15.10. 1977

Speeialia

The d e m o n s t r a t i o n t h a t t h e cerebral c o r t e x of all mice is c a p a b l e of some a r o m a t i z a t i o n is n o t e w o r t h y since o t h e r w o r k e r s h a v e failed to find s u c h e v i d e n c e in o t h e r r o d e n t s or mammals4,5, L This i n a b i l i t y to show a r o m a t i z a t i o n m a y be due t o low recoveries a n d / o r age d e p e n d e n t c h a n g e s in e n z y m e a c t i v i t y . T h a t c o r t e x can c o n c e n t r a t e radiolabel f r o m a d m i n i s t e r e d a n d r o g e n s h a s b e e n dem o n s t r a t e d b y several gr0ups 15-1s. H o w e v e r , t h e s e a u t h o r s did n o t d e t e r m i n e w h e t h e r a n y of t h e radioa c t i v i t y c o n c e n t r a t e d in t h i s b r a i n region was derived f r o m a r o m a t i z a t i o n of a c c u m u l a t e d androgen. H u m a n fetal c o r t e x h a s b e e n s h o w n t o a r o m a t i z e a n d r o g e n s 5 w h i c h is c o m p a r a b l e t o our o b s e r v a t i o n s on 30-day-old m o u s e c o r t e x . I n t h e p r e s e n t s t u d y no sex differences could be d e t e c t e d in c e r e b r a l c o r t e x a r o m a t i z a t i o n . Mouse h y p o t h a l a m i c tissue s h a s b e e n r e p o r t e d t o a r o m a tize a n d r o s t e n e d i o n e w i t h a male : female ratio of 3. Since n e i t h e r age of mice n o r p e r c e n t a g e c o n v e r s i o n s were g i v e n it was n o t possible t o m a k e d i r e c t c o m p a r i s o n s w i t h our results. Moreover, it was s u g g e s t e d t h a t T f m mice h a d a r o m a t i z i n g a b i l i t y similar t o t h a t of n o r m a l males< This

1393

is in c o n t r a s t t o t h e p r e s e n t d a t a w h e r e t h e a b i l i t y of b o t h m u t a n t s was t o w a r d s t h e female direction, a n d are cons i s t e n t w i t h d a t a using liver tissue w h e r e it w a s d e m o n s t r a t e d t h a t in a n d r o g e n i n s e n s i t i v e r a t s s t e r o i d m e t a b olism p r o c e e d s a l o n g female lines 1,. I t is also of i n t e r e s t t h a t t h e r e w a s a good c o n v e r s i o n of t e s t o s t e r o n e t o e s t r o n e in h y p o t h a l a m i c tissue of n o r m a l mice w h e r e a s in T f m t h e m a j o r e s t r o g e n f o r m e d was estradiol-17fl. S t u d i e s on f u r t h e r m e t a b o l i s m of t e s t o s t e r o n e in c e n t r a l tissues of genetic m u t a n t mice are still in progress.

15 E. O. Alvarez and V. D. Ramirez, Neuroendoerinology 6, 349 (1970). 16 M. Diamond and E. Dale, Anat. Ree. 157, 234 (1967). 17 G. Perez-Palacios, A. E. Perez, M. L. Cruz and C. Beyer, Biol. Reprod. 8, 395 (1973). 18 M. Vertes, A. Barnea, H. R. Lindner and R. J. B. King, Adv. exp. Med. Biol. 36, 137 (1973). 19 K. Einarsson, J.-B. Gustafsson and A. S. Goldman, Eur. J. Biochem. 31, 345 (1972).

Effects o f h a n d l i n g n o r m a l and b u l b e c t o m i z e d rats at adrenal and p l a s m a corticosterone levels I. L o y b e r , N. I. Perassi, F. A. L e c u o n a a n d M. E. P e r a l t a

Instituto de Fisiologta, Facuitad de Ciencias Mddicas, Universidad National de C6rdoba, Santa Rosa 1085, Cdrdoba (Argentina), 22 March 1977 Summary. N o r m a l a n d b u l b e c t o m i z e d a d u l t rats, male a n d female, h a n d l e d d a i l y for 4 weeks, s h o w p l a s m a a n d a d r e n a l c o r t i c o s t e r o n e values s i g n i f i c a n t l y lower t h a n t h e n o n - h a n d l e d ones. I n our p r e v i o u s i n v e s t i g a t i o n s , we were able t o s t u d y t h e effects of r e m o v a l of o l f a c t o r y b u l b s on t h e c o r t i c o a d r e n a l f u n c t i o n in female rats1, *. The a n i m a l s were h a n d l e d d u r i n g a p r e d e t e r m i n e d p e r i o d in o r d e r to avoid stress a t t h e m o m e n t of d e c a p i t a t i o n . B e a r i n g in m i n d t h a t t h e a c t i v i t y of a d r e n a l g l a n d s can be influenced b y m a n y factors, we w o n d e r e d w h e t h e r daily h a n d l i n g , in itself, w o u l d affect a d r e n o c o r t i c a l secretion. If t h i s were t h e case, w o u l d it r e v e a l itself in a similar m a n n e r in b o t h n o r m a l a n d b u l b e c t o m i z e d r a t s ? T h e p r e s e n t s t u d y was u n d e r t a k e n to clarify t h i s p o i n t . Material and methods. 67 w h i t e a d u l t r a t s b r e d in our i n s t i t u t e were u s e d : 34 females of b e t w e e n 160 a n d 270 g w e i g h t , a n d 33 males of b e t w e e n 230 a n d 360 g weight. All a n i m a l s w e r e k e p t u n d e r t h e s a m e conditions, h o u s e d 8 p e r cage, w i t h food a n d w a t e r available ad l i b i t u m .

A n i m a l s of each sex were d i v i d e d i n t o 4 lots: a) n o n h a n d l e d n o r m a l r a t s ; b) h a n d l e d n o r m a l r a t s ; c) n o n h a n d l e d r a t s w i t h b i l a t e r a l r e m o v a l of o l f a c t o r y bulbs; d) h a n d l e d rat's w i t h b i l a t e r a l r e m o v a l of o l f a c t o r y bulbs. H a n d l i n g c o n s i s t e d in t a k i n g r a t s one a t a t i m e a n d h o l d i n g t h e m for a few seconds o u t s i d e t h e cage, twice a d a y , for 5 d a y s in t h e week. The cages of n o n - h a n d l e d r a t s were only o p e n e d t w i c e a day. A f t e r 4 weeks' handling, t h e r a t s were d e c a p i t a t e d b y m e a n s of a s m a l l a n i m a l guillotine a t b e t w e e n 9 a n d 11 a.m., t h e t i m e b e t w e e n

1 2

I. Loyber, N. I. Perassi, F. A. Lecuona and M. E. Peralta, Neuroendocrinology 13, 93 (1973/74). I. Loyber, N. I. Perassi and F. A. Lecuona, Physiol. Behav. 17, 153 (1976).

Effects of handling normal and bulbectomized rats at adrenal and plasma corticosterone Cortieosterone

Female Normal Bulbeetomized Male Normal Bulbeetomized

Adrenal (~tg/g) Non-handled

Handled

Plasma ([zg/100 ml) Non-handled

Handled

20.9 4- 5.20* (8) 10.0 • 2.30 (7)

7.2 -+- 1.19 (8) 3.7 -t- 0.55 (11)

35.1 4- 4.98 (8) 19.9 • 1.97 (7)

14.1 4- 1.26 (8) 6.9 4- 1.10 (10)

10.5 4- 2.43 (9) 11.2 4- 2.18 (9)

3.8 4- 0.71 (8) 3.9 4-0.59 (7)

19.8 4- 3.70 (9) 20.2 4- 3.13 (9)

9.0 4- 1.48 (8) 7.3 4- 2.07 (7)

* Mean 4- SE. Number of animals is given in parentheses.

1394

Specialia

t a k i n g t h e a n i m a l o u t a n d its d e c a p i t a t i o n b e i n g n o t m o r e t h a n 5 sec. T r u n k b l o o d w a s collected a n d c e n t r i fuged. I n d i v i d u a l s a m p l e s of p l a s m a were frozen a n d k e p t for s u b s e q u e n t d e t e r m i n a t i o n of corticosterone. I m m e d i a t e l y a f t e r d e c a p i t a t i o n , t h e a d r e n a l g l a n d s were d i s s e c t e d a n d w e i g h e d t o a n a p p r o x i m a t i o n of 0.1 rag, h o m o g e n i z e d in a s a l i n e - a l c o h o l s o l u t i o n a n d t h e n frozen u n t i l c o r t i c o s t e r o n e was d e t e r m i n e d . B u l b e c t o m y was p e r f o r m e d a c c o r d i n g t o p r e v i o u s l y d e s c r i b e d t e c h n i q u e 2. A d r e n a l a n d p l a s m a c o r t i c o s t e r o n e was d e t e r m i n e d b y m e a n s of t h e R e r u p a n d H e d n e r m e t h o d 3 . R e s u l t s were evaluated by Student's t-test. Results and discussion. R e s u l t s o b t a i n e d m a y b e seen in t h e t a b l e . I n t h e first i n s t a n c e , w h e n c o m p a r i n g n o r m a l a n i m a l s , h a n d l e d w i t h n o n - h a n d l e d , i t m a y b e seen t h a t a d r e n a l a n d p l a s m a c o r t i c o s t e r o n e v a l u e s are s i g n i f i c a n t l y less in h a n d l e d r a t s , b o t h m a l e a n d female. I n e v e r y case, t h e d r o p was o v e r 5 0 % . W h e n c o n s i d e r i n g b u l b e c t o m i z e d a n i m a l s , h o w e v e r , we h a v e d e e m e d it m o r e c o n v e n i e n t to m a k e a s e p a r a t e a n a l y s i s of r e s u l t s o b t a i n e d in f e m a l e s a n d in males. I n b u l b e c t o m i z e d females, h a n d l e d a n i m a l s r e v e a l a d r e n a l a n d p l a s m a c o r t i c o s t e r o n e v a l u e s s i g n i f i c a n t l y lower t h a n i n n o n - h a n d l e d . F u r t h e r m o r e , as m a y b e seen in t h e t a b l e , t h e r e m o v a l of o l f a c t o r y b u l b s p r o d u c e s a l o w e r i n g in levels of b o t h p a r a m e t e r s in t h e h a n d l e d a n d n o n - h a n d l e d lots. C o m p a r i n g b u l b e c t o m i z e d w i t h n o r m a l a n i m a l s , i t m a y b e o b s e r v e d t h a t t h e difference in a d r e n a l corticos t e r o n e levels is s t a t i s t i c a l l y s i g n i f i c a n t in t h e h a n d l e d a n i m a l lot (p < 0.010). I n n o n - h a n d l e d a n i m a l s , d e s p i t e t h e d r o p of m o r e t h a n 5 0 % , t h i s does n o t b e c o m e signific a n t o w i n g t o t h e g r e a t d i s p e r s i o n of d a t a . R e s p e c t i n g t h e p l a s m a c o r t i c o s t e r o n e , t h e differences w i t h t h e n o r m a l anim a l s are s i g n i f i c a n t in b o t h lots, i.e. h a n d l e d (p < 0.020) a n d n o n - h a n d l e d (p < 0.005). R e g a r d i n g males, t h e h a n d l e d a n i m a l s also s h o w signific a n t l y lower v a l u e s t h a n n o n - h a n d l e d ( a d r e n a l c o r t i c o sterone, p < 0.010 a n d p l a s m a c o r t i c o s t e r o n e p < 0.005).

ENPERIENTIA 33/10

O n t h e o t h e r h a n d , t h e r e m o v a l of o l f a c t o r y b u l b s in n o w a y modifies t h e a d r e n a l or p l a s m a c o r t i c o s t e r o n e e i t h e r in h a n d l e d or n o n - h a n d l e d a n i m a l s . T h e effects of b u l b e c t o m y i n f e m a l e s c o n f i r m s p r e v i o u s f i n d i n g s in t h i s l a b o r a t o r y 1, 3, 4 r e g a r d i n g r e l a t i o n s h i p bet w e e n o l f a c t o r y b u l b s a n d a d r e n a l g l a n d s in r a t s . T h e f a c t h a s b e e n c o n f i r m e d b y o t h e r i n v e s t i g a t o r s as b e i n g obs e r v e d n o t o n l y i n r a t s 5, ~ b u t also in dogs L T h e f a c t t h a t b u l b e c t o m y h a s n o effect o n t h e levels of c o r t i c o s t e r o n e in m a l e s r e v e a l s a s e x u a l difference in t h e effects of bulbectomy on adrenal activity. While studying other p a r a m e t e r s in b u l b e c t o m i z e d rats, we h a v e , a t t h e s a m e t i m e , b e e n able t o o b s e r v e s e x u a l differences in t h e results, t o g e t h e r w i t h i n s u l i n s e n s i t i v i t y t e s t s a n d levels in s e r u m free f a t t y acids 9. These results indicate that handling reduces adrenal c o r t i c o s t e r o n e s y n t h e s i s in n o r m a l a n d b u l b e c t o m i z e d rats. T h e e x a c t n a t u r e of t h e m e c h a n i s m , w h e r e b y h a n d l i n g p r o d u c e s d i m i n i s h i n g c o r t i c o a d r e n a l a c t i v i t y , we c a n n o t e x p l a i n a t p r e s e n t . P e r h a p s v a r i a t i o n in t h e levels of a d r e n a l s t e r o i d s p r o d u c e d b y h a n d l i n g m i g h t cause a l t e r a t i o n s in s e n s i t i v i t y in h y p o t h a l a m i c areas w h i c h c o n t r o l t h e a d r e n a l f u n c t i o n , as L e v i n e a n d Mullins 1~ s u g g e s t w h e n r e f e r r i n g to r a t s h a n d l e d d u r i n g p r e p u b e r a l age. C. Rerup and S. Hedner, Acta endocr., ]~bh. 38, 220 (1961). J.A. Palma, N. I. Perassi and I. Loyber, Life Sci. JO, 909 (1971). M.X. Zarrow, P. A. Schlein, V. H. Denenberg and H. A. Cohen, Endocrinology 91, 191 (1972). 6 J. Dunn, M. Bennet and R. Peppler, Proe. Soc. exp. Biol. Med. 140, 755 (1972). 7 P. Arcangeli, V. Digiesi, G. Madeddu and R. Toccafondi, Experientia 29, 358 (1973). 8 N.I. Perassi, I. Loyber and J. A. Palma, Neuroendocrinology 9, 83 (1972). 9 N . I . Perassi and I. Loyber, Archs int. Physiol. Biochim. 81, 639 (1973). 10 S. Levine and R. F. Mul!ins, Jr, Science 152, 1585 (1966). 3 4 5

'Adrenalectomy, ovarian HCG-binding and the onset of female: puberty in the rat* J. W. S i e b e r s l a n d W. E n g e l 3

Universitiits-Frauenklinik, Hugstetterstrasse 55, D-7800 Freiburg, and Institut [i~r Humangenetik und Anthropologie der Universittit, Albertstrasse 17, D-7800 Freiburg (Federal Republic o/ Germany, B RD), 17 March 1977 Summary. T h e d e l a y of p u b e r t y o n s e t i n f e m a l e r a t s a d r e n a l e c t o m i z e d before t h e 2 5 t h d a y of age is d u e n e i t h e r t o c h a n g e s in t h e n u m b e r of o v a r i a n H C G - r e c e p t o r s n o r to a n a l t e r e d h o r m o n e a f f i n i t y of t h e s e receptors. I t is a s s u m e d t h a t glucocorticoids a c t on a n i n t r a c e l l u l a r level in t h e o v a r i a n cells, p o s s i b l y b y a l t e r a t i o n s of cyclic A M P - d e p e n d e n t phosphodiesterase activity. I n v o l v e m e n t of t h e a d r e n a l g l a n d s in t h e m a t u r a t i o n a n d f u n c t i o n of t h e r e p r o d u c t i v e s y s t e m of t h e female r a t h a ~ b e e n i m p l i e d in p r e v i o u s studies. A l t h o u g h a d u l t r a t s w i t h o u t a d r e n a l f u n c t i o n m a i n t a i n o v u l a t o r y cycles a n d c a n r e p r o d u c e , some i r r e g u l a r i t i e s of t h e cycle h a v e b e e n n o t e d 3. A c c o r d i n g t o P e p p l e r a n d J a c o b s 4, t h e a d r e n a l g l a n d s are n e c e s s a r y for n o r m a l follicular d e v e l o p m e n t as well as for t h e n o r m a l c o m p l e m e n t of eggs to b e shed. I n t h e i m m a t u r e f e m a l e r a t , t h e a d r e n a l s p l a y a d e f i n i t e role in d e t e r m i n i n g t h e t i m e of o n s e t of p u b e r t y (for r e v i e w see R a m a l e y S ) . Cory a n d B r i t t o n s i n d u c e d precocious puberty with adrenocortical extracts. Bilateral adrenale c t o m y in r a t s y o u n g e r t h a n 25 d a y s of age d e l a y s t h e n o r m a l a p p e a r a n c e of v a g i n a l o p e n i n g a n d o v u l a t i o n 7-~. A r e s t o r a t i o n c a n b e a c h i e v e d b y t h e a d m i n i s t r a t i o n of low doses of c o r t i c o s t e r o n e 1~ or b y a d r e n a l a u t o t r a n s p l a n t a t i o n a.

Adrenalectomy has been found to impair the sensitivity of i m m a t u r e f e m a l e r a t s t o g o n a d o t r o p h i n s n-18, w i t h cortisone returning response to normat n. Hypophysectomized immature rats showed an impaired response to h u m a n c h o r i o n i c g o n a d o t r o p h i n (HCG) unless a d r e n o c o r t i c o t r o p h i c h o r m o n e (ACTH) was also g i v e n 1.. Since t h e s e n s i t i v i t y of t h e o v a r y to g o n a d o t r o p h i n s is d e p e n d e n t on t h e specific m e m b r a n e - b o u n d g o n a d o t r o p h i n r e c e p t o r s , o n e m i g h t s p e c u l a t e t h a t t h e effects caused b y a d r e n a l e c t o m y i n female r a t s a r e d u e to t h e i m p a i r m e n t of t h e s e receptors. I n o r d e r t o t e s t t h i s possibility, we s t u d i e d t h e o v a r i a n H C G - b i n d i n g in a d r e n a l e c t o m i z e d rats during sexual maturation. Material and methods. W i s t a r female r a t s were r e c e i v e d a t 20 d a y s of age a n d d i v i d e d i n t o c o n t r o l (N = 28) a n d e x p e r i m e n t a l (N = 16) groups. B i l a t e r a l a d r e n a l e c t o m y w a s p e r f o r m e d b y a n a b d o m i n a l a p p r o a c h w i t h t h e ani-

Effects of handling normal and bulbectomized rats at adrenal and plasma corticosterone levels.

15.10. 1977 Speeialia The d e m o n s t r a t i o n t h a t t h e cerebral c o r t e x of all mice is c a p a b l e of some a r o m a t i z a t i o...
223KB Sizes 0 Downloads 0 Views