1321
relative lack of uterine stimulation, which contrasts with the experience with prostaglandins, made management more predictable. This is preferable in cases in which placental function is suspect and fetal monitoring in labour is essential. Further, the occurrence of bleeding at the time of catheter insertion is accepted as a contraindication to prostaglandin therapy because of the danger of hyperstimulation of the uterus, but in these circumstances oestradiol may be administered without risk. Insertion of a Foley catheter may change the shape of the cervix and improve the cervical score. 12 This is confirmed by the results in the control group. However, a much greater improvement in score was seen in the treatment group. More important, the clinical benefit in the form of shorter, easier labours seen in those patients who had oestradiol therapy supports the belief that this reduced the resistance offered by the cervix to the forces of parturition.
Preliminary Communications
We thank the obstetric staff of the Glasgow Royal Maternity Hospital for their co-operation. Schering Chemicals Limited supplied the oestradiol valerate and Hoechst Pharmaceuticals the tylose gel. A. J. G. was supported by a Cruden medical research scholarship awarded by the Scottish Hospital Endowments Research Trust.
Requests for reprints should be addressed to A. A. C. REFERENCES
Anderson, A. B. M., Turnbull, A. C. Am. J. Obstet. Gynec. 1969, 105, 1207. Calder, A. A., Embrey, M. P., Tait, T. Br. J. Obstet. Gynœc. 1977, 84, 264. Danforth, D. M. Am. J. Obstet. Gynec. 1947, 53, 541. Bryant, W. M., Greenwell, J. E., Weeks, P. M. Surgery Gynec. Obstet. 1968, 126, 27. 5. Danforth, D. N., Veis, A., Breen, M., Weinstein, H. G., Buckingham, J. C., Manalo, P. Am. J. Obstet. Gynec. 1974, 120, 641. 6. Pinto, R. M., Fisch, L., Schwarcz, R. L., Montiori, E. ibid. 1964, 90, 99. 7. Leppi, T. J., Kinnison, P. A. Anat. Rec. 1971, 170, 97. 8. Shepherd, J., Sims, C., Craft, I. Lancet, 1976, ii, 709. 9. Calder, A. A., William Blair Bell Memorial Lecture, Royal College of Obstetricians and Gynæcologists, June 1977. 10. Najak, Z., Hillier, K., Karim, S. M. M. J. Obstet. Gynœc. Br. Commonw. 1970, 77, 701. 11. Henneman, D. H. in Endocrinology (edited by R. D. Scow); p. 1109. New York,1973. 12. Embrey, M. P., Mollison, B. G. J. Obstet. Gynœc. Br. Commonw. 1967, 74, 1. 2. 3. 4.
44.
with that of immunoenkephalin-immunoreactive in more sites than extrapituitary reactivity was detected expected, and the findings suggest that A.c.T.H. and its fragments may have more important physiological and clinical implications than hitherto believed. to
compare the distribution of such
nerves.
CORTICOTROPIN-LIKE PEPTIDES IN CENTRAL NERVES AND IN ENDOCRINE CELLS OF GUT AND PANCREAS
nerves
A.C.T.H.
L. -I. LARSSON Institute of
DK-8000 Aarhus C, Denmark
Summary
MATERIALS AND METHODS
Medical Biochemistry, University of Aarhus,
Extrapituitary corticotropin-like
pep-
tides have been found in central nerves and in gastrointestinal and pancreatic endocrine cells. Previous biological and immunological data strongly indicate that the immunoreactivity present in the central nerves represents corticotropin (A.C.T.H.) or a closely related peptide. In some areas of the brain, the distribution of A.C.T.H. nerves parallels that of nerves containing the endogenous opioid ligand, enkephalin. Since A.C.T.H. fragments bind to the opioid receptor the two neuronal peptides may interact. The antiserum used demonstrates the COOH-terminus of the A.C.T.H. molecule, which is devoid of adrenocortical stimulatory activity. A COOHterminal A.C.T.H.-peptide, corticotropin-like intermediate peptide (C.L.I.P.), originally isolated from the pars intermedia, has been shown to stimulate release of pancreatic insulin. The presence of C.L.I.P.-like molecules in gut and pancreatic endocrine cells may indicate that C.L.I.P.’S insulin-releasing activity is physiologically important. Further, the occurrence of A.C.T.H.-related molecules in such cells may account for the ectopic A.C.T.H. syndrome associated with some tumours of gut and pancreas. INTRODUCTION
PEPTIDES with
corticotropin (A.C.T.H.) bioactivity and are present not only in pituitary but also in brain.1-4 A.C.T.H. and its fragments, furthermore, affect learning motivation, memory, and behaviour.s,6 Certain A.c.T.H. fragments also bind to brain opiate receptors,7 without exerting opiate-like effects.8 I decided to investigate whether A.C.T.H.-like peptides occur in neural structures of the brain and, if they do,
immunoreactivity
Human material was obtained at operations for various non-endocrine diseases. In addition, material was collected from green monkeys, dogs, cats, and rats. Some of the rats had been hypophysectomised two to four weeks before being killed. Tissue specimens from brain, gastrointestinal tract, pancreas, and pituitary were freeze-dried and fixed in paraformaldehyde vapour before being embedded in paraffin; alternatively, specimens were fixed in Bouin’s fluid and processed routinely. Sections 3 µm thick were tested for A.c.T.H. by an indirect immunocytochemical method.9 The antiserum had been raised in rabbits by intramuscular injection of purified porcine A.c.T.H. every 14 days for 5 months.lO As suggested by Sternberger,9 control tests were done after absorption of the antiserum with
purified porcine A.c.T.H. (1-39), A.C.T.H. (1-24) (’Synacthen’), metenkephalin (Beckman Ltd), and gastrin (synthetic human gastrin I, I.C.I.). The site of antigen/antibody reaction was displayed either with fluorescein isothiocyanate-labelled goat anti-rabbit IgG or with the peroxidase/antiperoxidase (P.A.P.) procedure of Sternberger. 9.11 RESULTS
Pituitary Numerous cells of the anterior lobe as well as the intermediate lobe were stained. Staining was abolished by pretreatment of the antiserum with porcine A.c.T.H. (1-39), but not with A.C.T.H. (1-24), metenkephalin, or gastrin. This pattern of reactivity was seen in all structures stained by the A.c.T.H. antiserum. Since A.c.T.H. (1-24) did not inactivate the antiserum, our anti-A.C.T.H. is presumably directed towards the COOH-terminal region of the molecule.
Brain and Spinal Cord
hypophysectomised animals had strongly immunoreactive nerves in the hypothalamus and other brain regions (fig. 1). The Both normal and
numerous
1322
spinal cord did not stain. Immunoreactive nerves were mapped in the normal and hypophysectomised rats. Briefly, dense networks of immunoreactive nerves were detected in the ventral part of the dorsomedial hypothalamic nucleus, the median eminence, and the periventricular thalamic nucleus. Less dense networks were found in the ventro-lateral aspect of the lateral septal nucleus, the nucleus interstitialis stria terminalis, the median aspect of the preoptic nucleus, the anterior hypothalamic nucleus, parts of the amygdaloid nucleus, the periaqueductal grey of the mid-brain, and the floor of the fourth ventricle. Regions ’containing no or only occasional immunoreactive fibres included the thoracic spinal cord, the spinal ganglia, the medulla oblongata, the cerebellum, the pineal gland, and the cerebral cortex. Immunoreactive nerve-cell bodies were detected only in the supraoptic nucleus (fig. 1). Distribution of the nerves seemed the same in normal and hypophysectomised rats. Gastrointestinal Tract and Pancreas Numerous immunoreactive endocrine-like cells occurred in the antropyloric mucosa of the stomach in the dog, cat, and rat (fig. 2), and their distribution was reminiscent of that of gastrin cells.12 In man and monkey, however, such cells were very rare. The duodenal mucosa of all species examined, including man, con-
tained scattered flask-shaped endocrine-like cells. These cells were most frequent in dog, cat, and man and less frequent in monkey and rat. Also the pancreas contained scattered, strongly immunoreactive cells. In human and canine pancreas, the cells occurred in both insular and extrainsular locations (fig. 2). In the rat, the immunoreactive cells were scattered at the periphery of the pancreatic islets. The distribution, topography, and morphology of the immunoreactive cells suggest that they are distinct from, and scarcer than, the four pancreatic endocrine cells which have been characterised-insulin, glucagon, somatostatin, and pancreatic polypeptide cells. Tumours
4 endocrine pancreatic tumours and 1 duodenal-wall examined for A.C.T.H.-like immunoreactivThe duodenal-wall tumour contained almost exclusiity. cells and was devoid of A.C.T.H. immunovely gastrin whereas 2 of the pancreatic tumours, both reactivity, associated with the Zollinger-Ellison syndrome, contained numerous A.C.T.H. immunoreactive cells. One of these tumours was already, known to lack cells reactive with an NH2-terminal A.C.T.H. antiserum. None of the tumours had been associated with the ectopic Cushing’s tumour were
syndrome.
,
DISCUSSION
These
findings
show that A.C.T.H.-like
peptides
are
brain, the immunowidespread body. of either occurrence reflects the reactivity probably in the
1—Brain sections from
hypophysectomised rats. The upper figure (A.C.T.H. immunostaining) shows numerous immunofluorescent varicose fibres of the periaqueductal grey matter (x273), whereas the lower figure shows immunoperoxidase staining of nerve-cell bodies of the supraoptic ( x187). Fig.
In the
Fig. 2-A.C.T.H. immunoreactive endocrine cells of dog antropyloric mucosa (top, x 187) and human pancreas (below, x 230). Immunoperoxidase staining for A.C.T.H.
1323 itself or of a very closely related molecule, since both bioactive and immunoreactive A.C.T.H. are known to occur in this site.3,4 The sequence A.C.T.H. (4-10) occurs in the &bgr;-lipotropin as well as &bgr;-melanocyte-stimulating hormone (&bgr;-M.S.H.) molecules. The inactivation experiments show, however, that even the sequence A.C.T.H. (1-24) fails to inactivate our antiserum; therefore the immunostaining is unlikely to depend on these molecules. Further, in experiments with metenkephalin as well as gastrin our antiserum did not bind these peptides. Since specific immunostaining persisted after hypophysectomy, the pituitary is very unlikely to be a source of central-nervous-system A.C.T.H..13 The distribution of A.c.T.H.-immunoreactive nerves was in some ways different from, and in others similar to, that of enkephalin nerves.14,15 No staining for A.C.T.H. was seen in, for example, the spinal cord or the medulla oblongata - regions reported to contain both enkephalin nerves and opiate receptors.14,15 However, the distributions overlapped—e.g., in the periventricular thalamic nuclei, the amygdala, and in the periventricular and ventral parts of the hypothalamus. Whether the overlaps reflects any functional interaction between nerves containing A.C.T.H.-like peptides and receptors for opioid peptides such as enkephalin deserves further study. A.c.T.H.-like immunoreactivity was detected also in gastrointestinal and pancreatic endocrine cells. Whereas in dog, cat, and rat the antropyloric mucosa contained immunoreactive cells in the same number and distribution as gastrin cells, in man the immunoreactive cells seemed confined to pancreas and duodenum. Enkephalin immunoreactivity has been reported to occur in the antral gastrin cells.16 Absorption of our antiserum with enkephalin and gastrin, however, did not affect the staining results. The nature of the immunoreactive peptide stored in these cells is unknown. The A.C.T.H. antiserum is specific for the COOH-terminal portion of A.C.T.H. A peptide corresponding to this portion has been isolated from the pituitary intermediate lobe and named corticotropin-like intermediate peptide (C.L.LP.).17,18 C.L.LP. is believed to arise by cleavage of A.C.T.H. (1-39) into a-M.S.H. and A.C.T.H. (18-39) (=C.L.I.P.).17 Its physiological importance is a mystery, since the adrenocortical stimulatory activity resides in the NH2-terminus of A.C.T.H. Recently, however, c.L.l.p. has been noted to be a potent insulin secretagogue. 19 The occurrence of c.L.i.p.-like peptides in gastrointestinal and pancreatic endocrine cells may suggest that C.L.I.P.’S insulin-releasing activity is physiologically important. Studies are under way to establish whether peptides resembling the NH2-terminal portion of A.C.T.H. also occur in the gut and pancreas although, for physiologic reasons, the secretion of adrenal-stimulating peptides from the gut A.C.T.H.
seems
unlikely.
The presence of c.L.i.p.-like molecules in gut and pancreatic endocrine cells may explain why tumours in this region sometimes cause an ectopic Cushing’s syndrome. Interestingly, one tumour, devoid of NH2-terminal A.C.T.H. immunoreactivity, proved to contain numerous cells reactive with the COOH-terminus-specific A.C.T.H. antiserum. Although still very preliminary, this observation indicates that some tumour cells, and perhaps their corresponding normal cells, predominantly contain C.L.i.p.-like peptides. Similar observations have previously been made with radioimmunoassay of a bronchial carcinoid tumour.20
Since I submitted this paper some pertinent new data have emerged. We find that, in the rat, A.C.T.H.immunoreactive antropyloric cells are identical to the gastrin cells (unpublished). Studies with yet another COOH-terminus-specific A.C.T.H. antiserum have, furthermore, produced results identical to those described above. In absorption studies, both antisera were inactivated by highly purified A.C.T.H. (1-39) (Ferring) but not by A.C.T.H. (1-24) (Ciba). Mains and his coworkers2l have reported the occurrence of a large 31 000 dalton peptide that contains the sequence of both A.C.T.H. and enkephalin. The existence of both enkephalin-likel6 and A.C.T.H.-like immunoreactivity in the antral gastrin cells may indicate that these cells, too, manufacture this putative precursor molucule. I thank Dr U.
Lundkvist, Pharmacia, Sweden, for A.C.T.H. antiand Mrs J. B. Lauridsen and Mrs E. Peterson for technical assistance. The work was supported by a grant from the Danish M.R.C.
serum
REFERENCES
1. Guillemin, R., Schally, A. V., Lipscomb, H. S., Andersen, R. N., Long, J. M. Endocrinology, 1962, 70, 471. 2. Schally, A. V., Lipscomb, H. S., Long, J. H., Dear, W. E., Guillemin, R. ibid. 1962, 70, 478. 3. Krieger, D. T., Liotta, A., Brownstein, M. J. Proc. natn. Acad. Sci., U.S.A., 1977. 74, 648. 4. Krieger, D. T., Liotta, A., Brownstein, M. J. Brain Res. 1977, 128, 575. 5. DeWied, D. in The Neurosciences Third Study Program (edited by F. O. Schmitt and F. G. Worden): p. 653. Cambridge, Mass., 1974. 6. Gispen, W. H., Wiegant, V. M., Greven, H. M., DeWied, D. Life Sci. 1976, 17, 645. 7. Terenius, L. J. Pharm. Pharmacol. 1975, 27, 450. 8. Ling, N., Guillemin, R. Proc. natn. Acad. Sci., U.S.A. 1976, 73, 3308. 9. Sternberger, L. Immunocytochemistry. New Jersey, 1974. 10. Håkanson, R., Sundler, F., Larsson, L. -I., Ekman, R., Sjöberg, N. -O. J. Histochem. Cytochem. 1975, 23, 65. 11. Larsson, L. -I., Hirsch, M. A., Hoist, J. J., Ingemansson, S., Kühl, C., Lindkaer Jensen, S., Lundquist, G., Rehfeld, J. F., Schwartz, T. Lancet, 1977, i, 666. 12. Larsson, L. -I., Sundler, F., Håkanson, R., Grimelius, L., Rehfeld, J. F., Stadil, F. J. Histochem. Cytochem. 1974, 22, 419. 13. Bergland, R. M., Davis, S. L., Page, R. B. Lancet, 1977, ii, 276. 14. Simantov, R., Kuhar, M. J., Uhl, G. R., Snyder, S. H. Proc. natn. Acad. Sci., U.S.A., 1977, 74, 2167. 15. Hökfelt, T., Elde, R., Johansson, O., Terenius, L., Stein, L. Neurosci. Letters, 1977,5,25. 16. Polak, J. M., Sullivan, S. N., Bloom, S. R., Facer, P., Pearse, A. G. E. Lancet, 1977, i, 972. 17. Scott, A. P., Ratcliffe, J. G., Rees, L. H., Landon, J., Bennett, H. P. J., Lowry, P. J., McMartin, C. Nature, 1973, 244, 65. 18. Scott, A. P., Lowry, P. J., Bennett, H. P. J., McMartin, C., Ratcliffe, J. G. J. Endocr. 1974, 61, 369. 19. Beloff-Chain, A., Edwardson, J. A., Hawthorn, J. ibid. 1977, 73, 28P. 20. Scott, A. P., Bennett, H. P. J., Lowry, P. J. McMartin, C., Ratcliffe, J. G. ibid. 1972, 55, 36. 21. Mains, R. E., Eipper, B. A., Ling, N. Proc. natn. Acad. Sci. U.S.A. 1977, 74, 3014.
TREATMENT OF CARCINOID LIVER METASTASES BY HEPATIC-ARTERY EMBOLISATION I. M. MODLIN J. ALLISON W. J. JENKINS Departments of Diagnostic Radiology, Surgery and Medicine, Hammersmith Hospital and Royal Postgraduate Medical D.
School, Du Cane Road, London W12
Summary
Two
patients
with
multiple hepatic
car-
cinoid metastases experienced considerable symptomatic relief after the hepatic artery was embolised with fragments of absorbable gelatin sponge administered through a percutaneous arterial catheter. With adequate pharmacological cover the technique is a
safe, effective, and relatively painless treatment for condition which is usually very difficult to manage.
a
relative lack of uterine stimulation, which contrasts with the experience with prostaglandins, made management more predictable. This is preferable in cases in which placental function is suspect and fetal monitoring in labour is essential. Further, the occurrence of bleeding at the time of catheter insertion is accepted as a contraindication to prostaglandin therapy because of the danger of hyperstimulation of the uterus, but in these circumstances oestradiol may be administered without risk. Insertion of a Foley catheter may change the shape of the cervix and improve the cervical score. 12 This is confirmed by the results in the control group. However, a much greater improvement in score was seen in the treatment group. More important, the clinical benefit in the form of shorter, easier labours seen in those patients who had oestradiol therapy supports the belief that this reduced the resistance offered by the cervix to the forces of parturition.
Preliminary Communications
We thank the obstetric staff of the Glasgow Royal Maternity Hospital for their co-operation. Schering Chemicals Limited supplied the oestradiol valerate and Hoechst Pharmaceuticals the tylose gel. A. J. G. was supported by a Cruden medical research scholarship awarded by the Scottish Hospital Endowments Research Trust.
Requests for reprints should be addressed to A. A. C. REFERENCES
Anderson, A. B. M., Turnbull, A. C. Am. J. Obstet. Gynec. 1969, 105, 1207. Calder, A. A., Embrey, M. P., Tait, T. Br. J. Obstet. Gynœc. 1977, 84, 264. Danforth, D. M. Am. J. Obstet. Gynec. 1947, 53, 541. Bryant, W. M., Greenwell, J. E., Weeks, P. M. Surgery Gynec. Obstet. 1968, 126, 27. 5. Danforth, D. N., Veis, A., Breen, M., Weinstein, H. G., Buckingham, J. C., Manalo, P. Am. J. Obstet. Gynec. 1974, 120, 641. 6. Pinto, R. M., Fisch, L., Schwarcz, R. L., Montiori, E. ibid. 1964, 90, 99. 7. Leppi, T. J., Kinnison, P. A. Anat. Rec. 1971, 170, 97. 8. Shepherd, J., Sims, C., Craft, I. Lancet, 1976, ii, 709. 9. Calder, A. A., William Blair Bell Memorial Lecture, Royal College of Obstetricians and Gynæcologists, June 1977. 10. Najak, Z., Hillier, K., Karim, S. M. M. J. Obstet. Gynœc. Br. Commonw. 1970, 77, 701. 11. Henneman, D. H. in Endocrinology (edited by R. D. Scow); p. 1109. New York,1973. 12. Embrey, M. P., Mollison, B. G. J. Obstet. Gynœc. Br. Commonw. 1967, 74, 1. 2. 3. 4.
44.
with that of immunoenkephalin-immunoreactive in more sites than extrapituitary reactivity was detected expected, and the findings suggest that A.c.T.H. and its fragments may have more important physiological and clinical implications than hitherto believed. to
compare the distribution of such
nerves.
CORTICOTROPIN-LIKE PEPTIDES IN CENTRAL NERVES AND IN ENDOCRINE CELLS OF GUT AND PANCREAS
nerves
A.C.T.H.
L. -I. LARSSON Institute of
DK-8000 Aarhus C, Denmark
Summary
MATERIALS AND METHODS
Medical Biochemistry, University of Aarhus,
Extrapituitary corticotropin-like
pep-
tides have been found in central nerves and in gastrointestinal and pancreatic endocrine cells. Previous biological and immunological data strongly indicate that the immunoreactivity present in the central nerves represents corticotropin (A.C.T.H.) or a closely related peptide. In some areas of the brain, the distribution of A.C.T.H. nerves parallels that of nerves containing the endogenous opioid ligand, enkephalin. Since A.C.T.H. fragments bind to the opioid receptor the two neuronal peptides may interact. The antiserum used demonstrates the COOH-terminus of the A.C.T.H. molecule, which is devoid of adrenocortical stimulatory activity. A COOHterminal A.C.T.H.-peptide, corticotropin-like intermediate peptide (C.L.I.P.), originally isolated from the pars intermedia, has been shown to stimulate release of pancreatic insulin. The presence of C.L.I.P.-like molecules in gut and pancreatic endocrine cells may indicate that C.L.I.P.’S insulin-releasing activity is physiologically important. Further, the occurrence of A.C.T.H.-related molecules in such cells may account for the ectopic A.C.T.H. syndrome associated with some tumours of gut and pancreas. INTRODUCTION
PEPTIDES with
corticotropin (A.C.T.H.) bioactivity and are present not only in pituitary but also in brain.1-4 A.C.T.H. and its fragments, furthermore, affect learning motivation, memory, and behaviour.s,6 Certain A.c.T.H. fragments also bind to brain opiate receptors,7 without exerting opiate-like effects.8 I decided to investigate whether A.C.T.H.-like peptides occur in neural structures of the brain and, if they do,
immunoreactivity
Human material was obtained at operations for various non-endocrine diseases. In addition, material was collected from green monkeys, dogs, cats, and rats. Some of the rats had been hypophysectomised two to four weeks before being killed. Tissue specimens from brain, gastrointestinal tract, pancreas, and pituitary were freeze-dried and fixed in paraformaldehyde vapour before being embedded in paraffin; alternatively, specimens were fixed in Bouin’s fluid and processed routinely. Sections 3 µm thick were tested for A.c.T.H. by an indirect immunocytochemical method.9 The antiserum had been raised in rabbits by intramuscular injection of purified porcine A.c.T.H. every 14 days for 5 months.lO As suggested by Sternberger,9 control tests were done after absorption of the antiserum with
purified porcine A.c.T.H. (1-39), A.C.T.H. (1-24) (’Synacthen’), metenkephalin (Beckman Ltd), and gastrin (synthetic human gastrin I, I.C.I.). The site of antigen/antibody reaction was displayed either with fluorescein isothiocyanate-labelled goat anti-rabbit IgG or with the peroxidase/antiperoxidase (P.A.P.) procedure of Sternberger. 9.11 RESULTS
Pituitary Numerous cells of the anterior lobe as well as the intermediate lobe were stained. Staining was abolished by pretreatment of the antiserum with porcine A.c.T.H. (1-39), but not with A.C.T.H. (1-24), metenkephalin, or gastrin. This pattern of reactivity was seen in all structures stained by the A.c.T.H. antiserum. Since A.c.T.H. (1-24) did not inactivate the antiserum, our anti-A.C.T.H. is presumably directed towards the COOH-terminal region of the molecule.
Brain and Spinal Cord
hypophysectomised animals had strongly immunoreactive nerves in the hypothalamus and other brain regions (fig. 1). The Both normal and
numerous
1322
spinal cord did not stain. Immunoreactive nerves were mapped in the normal and hypophysectomised rats. Briefly, dense networks of immunoreactive nerves were detected in the ventral part of the dorsomedial hypothalamic nucleus, the median eminence, and the periventricular thalamic nucleus. Less dense networks were found in the ventro-lateral aspect of the lateral septal nucleus, the nucleus interstitialis stria terminalis, the median aspect of the preoptic nucleus, the anterior hypothalamic nucleus, parts of the amygdaloid nucleus, the periaqueductal grey of the mid-brain, and the floor of the fourth ventricle. Regions ’containing no or only occasional immunoreactive fibres included the thoracic spinal cord, the spinal ganglia, the medulla oblongata, the cerebellum, the pineal gland, and the cerebral cortex. Immunoreactive nerve-cell bodies were detected only in the supraoptic nucleus (fig. 1). Distribution of the nerves seemed the same in normal and hypophysectomised rats. Gastrointestinal Tract and Pancreas Numerous immunoreactive endocrine-like cells occurred in the antropyloric mucosa of the stomach in the dog, cat, and rat (fig. 2), and their distribution was reminiscent of that of gastrin cells.12 In man and monkey, however, such cells were very rare. The duodenal mucosa of all species examined, including man, con-
tained scattered flask-shaped endocrine-like cells. These cells were most frequent in dog, cat, and man and less frequent in monkey and rat. Also the pancreas contained scattered, strongly immunoreactive cells. In human and canine pancreas, the cells occurred in both insular and extrainsular locations (fig. 2). In the rat, the immunoreactive cells were scattered at the periphery of the pancreatic islets. The distribution, topography, and morphology of the immunoreactive cells suggest that they are distinct from, and scarcer than, the four pancreatic endocrine cells which have been characterised-insulin, glucagon, somatostatin, and pancreatic polypeptide cells. Tumours
4 endocrine pancreatic tumours and 1 duodenal-wall examined for A.C.T.H.-like immunoreactivThe duodenal-wall tumour contained almost exclusiity. cells and was devoid of A.C.T.H. immunovely gastrin whereas 2 of the pancreatic tumours, both reactivity, associated with the Zollinger-Ellison syndrome, contained numerous A.C.T.H. immunoreactive cells. One of these tumours was already, known to lack cells reactive with an NH2-terminal A.C.T.H. antiserum. None of the tumours had been associated with the ectopic Cushing’s tumour were
syndrome.
,
DISCUSSION
These
findings
show that A.C.T.H.-like
peptides
are
brain, the immunowidespread body. of either occurrence reflects the reactivity probably in the
1—Brain sections from
hypophysectomised rats. The upper figure (A.C.T.H. immunostaining) shows numerous immunofluorescent varicose fibres of the periaqueductal grey matter (x273), whereas the lower figure shows immunoperoxidase staining of nerve-cell bodies of the supraoptic ( x187). Fig.
In the
Fig. 2-A.C.T.H. immunoreactive endocrine cells of dog antropyloric mucosa (top, x 187) and human pancreas (below, x 230). Immunoperoxidase staining for A.C.T.H.
1323 itself or of a very closely related molecule, since both bioactive and immunoreactive A.C.T.H. are known to occur in this site.3,4 The sequence A.C.T.H. (4-10) occurs in the &bgr;-lipotropin as well as &bgr;-melanocyte-stimulating hormone (&bgr;-M.S.H.) molecules. The inactivation experiments show, however, that even the sequence A.C.T.H. (1-24) fails to inactivate our antiserum; therefore the immunostaining is unlikely to depend on these molecules. Further, in experiments with metenkephalin as well as gastrin our antiserum did not bind these peptides. Since specific immunostaining persisted after hypophysectomy, the pituitary is very unlikely to be a source of central-nervous-system A.C.T.H..13 The distribution of A.c.T.H.-immunoreactive nerves was in some ways different from, and in others similar to, that of enkephalin nerves.14,15 No staining for A.C.T.H. was seen in, for example, the spinal cord or the medulla oblongata - regions reported to contain both enkephalin nerves and opiate receptors.14,15 However, the distributions overlapped—e.g., in the periventricular thalamic nuclei, the amygdala, and in the periventricular and ventral parts of the hypothalamus. Whether the overlaps reflects any functional interaction between nerves containing A.C.T.H.-like peptides and receptors for opioid peptides such as enkephalin deserves further study. A.c.T.H.-like immunoreactivity was detected also in gastrointestinal and pancreatic endocrine cells. Whereas in dog, cat, and rat the antropyloric mucosa contained immunoreactive cells in the same number and distribution as gastrin cells, in man the immunoreactive cells seemed confined to pancreas and duodenum. Enkephalin immunoreactivity has been reported to occur in the antral gastrin cells.16 Absorption of our antiserum with enkephalin and gastrin, however, did not affect the staining results. The nature of the immunoreactive peptide stored in these cells is unknown. The A.C.T.H. antiserum is specific for the COOH-terminal portion of A.C.T.H. A peptide corresponding to this portion has been isolated from the pituitary intermediate lobe and named corticotropin-like intermediate peptide (C.L.LP.).17,18 C.L.LP. is believed to arise by cleavage of A.C.T.H. (1-39) into a-M.S.H. and A.C.T.H. (18-39) (=C.L.I.P.).17 Its physiological importance is a mystery, since the adrenocortical stimulatory activity resides in the NH2-terminus of A.C.T.H. Recently, however, c.L.l.p. has been noted to be a potent insulin secretagogue. 19 The occurrence of c.L.i.p.-like peptides in gastrointestinal and pancreatic endocrine cells may suggest that C.L.I.P.’S insulin-releasing activity is physiologically important. Studies are under way to establish whether peptides resembling the NH2-terminal portion of A.C.T.H. also occur in the gut and pancreas although, for physiologic reasons, the secretion of adrenal-stimulating peptides from the gut A.C.T.H.
seems
unlikely.
The presence of c.L.i.p.-like molecules in gut and pancreatic endocrine cells may explain why tumours in this region sometimes cause an ectopic Cushing’s syndrome. Interestingly, one tumour, devoid of NH2-terminal A.C.T.H. immunoreactivity, proved to contain numerous cells reactive with the COOH-terminus-specific A.C.T.H. antiserum. Although still very preliminary, this observation indicates that some tumour cells, and perhaps their corresponding normal cells, predominantly contain C.L.i.p.-like peptides. Similar observations have previously been made with radioimmunoassay of a bronchial carcinoid tumour.20
Since I submitted this paper some pertinent new data have emerged. We find that, in the rat, A.C.T.H.immunoreactive antropyloric cells are identical to the gastrin cells (unpublished). Studies with yet another COOH-terminus-specific A.C.T.H. antiserum have, furthermore, produced results identical to those described above. In absorption studies, both antisera were inactivated by highly purified A.C.T.H. (1-39) (Ferring) but not by A.C.T.H. (1-24) (Ciba). Mains and his coworkers2l have reported the occurrence of a large 31 000 dalton peptide that contains the sequence of both A.C.T.H. and enkephalin. The existence of both enkephalin-likel6 and A.C.T.H.-like immunoreactivity in the antral gastrin cells may indicate that these cells, too, manufacture this putative precursor molucule. I thank Dr U.
Lundkvist, Pharmacia, Sweden, for A.C.T.H. antiand Mrs J. B. Lauridsen and Mrs E. Peterson for technical assistance. The work was supported by a grant from the Danish M.R.C.
serum
REFERENCES
1. Guillemin, R., Schally, A. V., Lipscomb, H. S., Andersen, R. N., Long, J. M. Endocrinology, 1962, 70, 471. 2. Schally, A. V., Lipscomb, H. S., Long, J. H., Dear, W. E., Guillemin, R. ibid. 1962, 70, 478. 3. Krieger, D. T., Liotta, A., Brownstein, M. J. Proc. natn. Acad. Sci., U.S.A., 1977. 74, 648. 4. Krieger, D. T., Liotta, A., Brownstein, M. J. Brain Res. 1977, 128, 575. 5. DeWied, D. in The Neurosciences Third Study Program (edited by F. O. Schmitt and F. G. Worden): p. 653. Cambridge, Mass., 1974. 6. Gispen, W. H., Wiegant, V. M., Greven, H. M., DeWied, D. Life Sci. 1976, 17, 645. 7. Terenius, L. J. Pharm. Pharmacol. 1975, 27, 450. 8. Ling, N., Guillemin, R. Proc. natn. Acad. Sci., U.S.A. 1976, 73, 3308. 9. Sternberger, L. Immunocytochemistry. New Jersey, 1974. 10. Håkanson, R., Sundler, F., Larsson, L. -I., Ekman, R., Sjöberg, N. -O. J. Histochem. Cytochem. 1975, 23, 65. 11. Larsson, L. -I., Hirsch, M. A., Hoist, J. J., Ingemansson, S., Kühl, C., Lindkaer Jensen, S., Lundquist, G., Rehfeld, J. F., Schwartz, T. Lancet, 1977, i, 666. 12. Larsson, L. -I., Sundler, F., Håkanson, R., Grimelius, L., Rehfeld, J. F., Stadil, F. J. Histochem. Cytochem. 1974, 22, 419. 13. Bergland, R. M., Davis, S. L., Page, R. B. Lancet, 1977, ii, 276. 14. Simantov, R., Kuhar, M. J., Uhl, G. R., Snyder, S. H. Proc. natn. Acad. Sci., U.S.A., 1977, 74, 2167. 15. Hökfelt, T., Elde, R., Johansson, O., Terenius, L., Stein, L. Neurosci. Letters, 1977,5,25. 16. Polak, J. M., Sullivan, S. N., Bloom, S. R., Facer, P., Pearse, A. G. E. Lancet, 1977, i, 972. 17. Scott, A. P., Ratcliffe, J. G., Rees, L. H., Landon, J., Bennett, H. P. J., Lowry, P. J., McMartin, C. Nature, 1973, 244, 65. 18. Scott, A. P., Lowry, P. J., Bennett, H. P. J., McMartin, C., Ratcliffe, J. G. J. Endocr. 1974, 61, 369. 19. Beloff-Chain, A., Edwardson, J. A., Hawthorn, J. ibid. 1977, 73, 28P. 20. Scott, A. P., Bennett, H. P. J., Lowry, P. J. McMartin, C., Ratcliffe, J. G. ibid. 1972, 55, 36. 21. Mains, R. E., Eipper, B. A., Ling, N. Proc. natn. Acad. Sci. U.S.A. 1977, 74, 3014.
TREATMENT OF CARCINOID LIVER METASTASES BY HEPATIC-ARTERY EMBOLISATION I. M. MODLIN J. ALLISON W. J. JENKINS Departments of Diagnostic Radiology, Surgery and Medicine, Hammersmith Hospital and Royal Postgraduate Medical D.
School, Du Cane Road, London W12
Summary
Two
patients
with
multiple hepatic
car-
cinoid metastases experienced considerable symptomatic relief after the hepatic artery was embolised with fragments of absorbable gelatin sponge administered through a percutaneous arterial catheter. With adequate pharmacological cover the technique is a
safe, effective, and relatively painless treatment for condition which is usually very difficult to manage.
a
