Acta Physiol 2014, 212, 189–190
ExActa Extreme environments As a physiologist, one can often not help but marvel at the versatility of the mammalian body with regard to its adaptability to changing environments. In an earlier contribution to the Exacta series, we have discussed the latest developments in research on thermoregulation, introducing the tiny water bear (tardigrade), which is equipped with resources to not only withstand temperatures near absolute zero or centuries without any water, but also being shot into outer space (Persson & Persson 2012). With increasing structural complexity, organisms become, obviously, more restricted to certain environmental conditions. Mammals, nevertheless, survive and often thrive in environments ranging from tropical rainforests to eternal ice, but are, however, more limited than small eukaryotes when it comes to pressure, radiation or toxin exposure, to name but a few. Changing climatic conditions induce a change in the spectrum of mammals inhabiting certain regions of the globe (World Wildlife Fund 2014); mammals try to migrate or adapt – if they can (Schloss et al. 2012). But not only comparative physiologists are interested in the adaptability of organisms to environmental stress. Humans have climbed the highest mountains (Hunt 1953), dived in submarines to depths below 10,900 metres (Naval History & Heritage 2014), regularly look at the inside of active volcanoes (Solid Earth Science Working Group 2014) and reached the poles of the globe quite some time ago, let alone those who have left earth’s gravity. Following the headlinegenerating first explorations of these extreme environments, a current tendency towards the voluntary self-exposition to extreme environments for recreational purposes (and for showing off to one’s peers afterwards) is notable, as in: I can pay for it, so I am entitled to see/do/touch it – always aiming higher/deeper/further etc. Apart from these endeavours, limited exposition to challenging environments is used clinically, as in therapeutic hyperthermia, cryotherapy, chemotherapy or irradiation. Thus, the reaction of the human body or appropriately chosen animal models to extreme environments remains a current topic in physiological research. Underwater diving for leisure is a comparatively old activity (Richardson 1999), and not only the battle for ever-increasing depths fostered physiological research on that topic. The works of Tocco et al. (2013) and Marabotti et al. (2013) are especially relevant with
regard to current demographic developments, that is, an elderly, but still very active population. Responses to hyper-and hypothermic challenges are a classic topic in environmental physiology. Bain and co-workers (Bain et al. 2012) recently investigated the effect of hot fluid ingestion during physical activity and found that body heat storage is lower with warm water ingestion, possibly because of the activation of warm-sensitive thermosensors in the upper gastrointestinal tract. Fieger and Wong (Fieger & Wong 2012) have recently shed light on the mechanisms of thermoregulatory vasodilation during heat stress in humans. Further interesting findings have been reported by Yoshihara et al. (2013) on heat stress signalling, and by Machado-Moreira & Taylor (2012) on sudomotor response physiology. Hypothermia has recently been investigated by (Wold et al. 2013) with regard to myocardial calcium content in an in vivo rat model. Exposure to heights and the development of mountain sickness comprise, in contrast, a number of different stimuli. The role of the natriuretic peptide system in this pathology has been investigated thoroughly in (Woods et al. 2012). In a similar line, Kiviniemi et al. (2012) have investigated complex sympathoexcitatory manoeuvres to elicit the contribution of non-a-adrenergic mechanisms to systemic vascular conductance. Sudden-onset exercise may, in contrast to chronic training studies, also be seen as a challenging change of the environmental conditions that an individual undergoes. In this regard, Petersen et al. (2012) found a remarkable effect of antioxidant N-Acetylcysteine on acute exercise adaptation. Acute exercise exerts a number of interesting responses, among them a modulation of flow-mediated vascular responses to fluid shear stress (Llewellyn et al. 2012). Exposure to environmental toxins is a cluster of (often highly politicized) topics which, when considering the general image, is well beyond the reach of the physiologist alone. Nevertheless, certain toxins such as cigarette smoke (Cao et al. 2013) (Yu et al. 2012), hyperoxia (Micarelli et al. 2013) or hypercapnia (Taxini et al. 2013) fall within the physiologist’s realm. Keramidas et al. have demonstrated the effects of carbon monoxide during exercise performance (Keramidas et al. 2012) – by the way, did you cycle to the lab this morning? Acta Physiologica, although not specifically targeted to environmental or comparative physiology, continues
© 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd, doi: 10.1111/apha.12347
189
ExActa
· A Bondke Persson and P B Persson
to provide interesting data on environmental stimuli, and the reaction of the human/mammalian body to these, showing, in addition to scientific insight, how integrative physiology is very much alive.
Conflict of interest None.
A. Bondke Persson and P. B. Persson Institute of Vegetative Physiology, Charite-Universitaetsmedizin Berlin, Berlin, Germany E-mail: [email protected] References Bain, A.R., Lesperance, N.C. & Jay, O. 2012. Body heat storage during physical activity is lower with hot fluid ingestion under conditions that permit full evaporation. Acta Physiol 206, 98–108. Cao, L., Xu, C.B., Zhang, Y., Cao, Y.X. & Edvinsson, L. 2013. Secondhand cigarette smoke exposure causes upregulation of cerebrovascular 5-HT1B receptors via the Raf/ ERK/MAPK pathway in rats. Acta Physiol 207, 183–193. Fieger, S.M. & Wong, B.J. 2012. No direct role for A1/A2 adenosine receptor activation to reflex cutaneous vasodilatation during whole-body heat stress in humans. Acta Physiol 205, 403–410. Hunt, J. 1953. The Ascent of Everest. Hodder & Stoughton, London. Keramidas, M.E., Kounalakis, S.N., Eiken, O. & Mekjavic, I.B. 2012. Carbon monoxide exposure during exercise performance: muscle and cerebral oxygenation. Acta Physiol 204, 544–554. Kiviniemi, A.M., Frances, M.F., Rachinsky, M., Craen, R., Petrella, R.J., Huikuri, H.V., Tulppo, M.P. & Shoemaker, J.K. 2012. Non-alpha-adrenergic effects on systemic vascular conductance during lower-body negative pressure, static exercise and muscle metaboreflex activation. Acta Physiol 206, 51–61. Llewellyn, T.L., Chaffin, M.E., Berg, K.E. & Meendering, J.R. 2012. The relationship between shear rate and flowmediated dilation is altered by acute exercise. Acta Physiol 205, 394–402. Machado-Moreira, C.A. & Taylor, N.A.S. 2012. Sudomotor responses from glabrous and non-glabrous skin during cognitive and painful stimulations following passive heating. Acta Physiol 204, 571–581. Marabotti, C., Scalzini, A., Menicucci, D., Passera, M., Bedini, R. & L’Abbate, A. 2013. Cardiovascular changes during
190
Acta Physiol 2014, 212, 189–190 SCUBA diving: an underwater Doppler echocardiographic study. Acta Physiol 209, 62–68. Micarelli, A., Jacobsson, H., Larsson, S.A., Jonsson, C. & Pagani, M. 2013. Neurobiological insight into hyperbaric hyperoxia. Acta Physiol 209, 69–76. Naval History and Heritage. 2014. Dictionary of American naval fighting ships: Trieste. (online) Available at: http:// www.history.navy.mil/danfs/t8/trieste.htm (accessed July 9, 2014). Persson, A.B. & Persson, P.B. 2012. Getting a kick out of thermoregulation. Acta Physiol (Oxf) 204, 291–293. Petersen, A.C., McKenna, M.J., Medved, I., Murphy, K.T., Brown, M.J., Della Gatta, P. & Cameron-Smith, D. 2012. Infusion with the antioxidant N-acetylcysteine attenuates early adaptive responses to exercise in human skeletal muscle. Acta Physiol 204, 382–392. Richardson, D. 1999. A brief history of recreational diving in the United States. SPUMS J 29, 173–176. Schloss, C.A., Nu~ nez, T.A. & Lawler, J.J. 2012. Dispersal will limit ability of mammals to track climate change in the Western Hemisphere. Proc Natl Acad Sci USA 109, 8606–8611. Solid Earth Science Working Group. 2014. Nasa’s Research: Volcanoes. (online) Available at: http://solidearth.jpl.nasa. gov/PAGES/volc04.html (accessed July 9, 2014). Taxini, C.L., Puga, C.C.I., Dias, M.B., Bıcego, K.C. & Gargaglioni, L.H. 2013. Ionotropic but not metabotropic glutamatergic receptors in the locus coeruleus modulate the hypercapnic ventilatory response in unanaesthetized rats. Acta Physiol 208, 125–135. Tocco, F., Marongiu, E., Pinna, M., Roberto, S., Pusceddu, M., Angius, L., Migliaccio, G., Milia, R., Concu, A. & Crisafulli, A. 2013. Assessment of circulatory adjustments during underwater apnoea in elite divers by means of a portable device. Acta Physiol (Oxf) 207, 290–298. Wold, R.M., Kondratiev, T. & Tveita, T. 2013. Myocardial calcium overload during graded hypothermia and after rewarming in an in vivo rat model. Acta Physiol 207, 460–469. Woods, D.R., Begley, J., Stacey, M., Smith, C., Boos, C.J., Hooper, T., Hawkins, A., Hodkinson, P., Green, N. & Mellor, A. 2012. Severe acute mountain sickness, brain natriuretic peptide and NT-proBNP in humans. Acta Physiol 205, 349–355. World Wildlife Fund. 2014. The impacts of climate change on nature. (online) Available at: http://wwf.panda.org/about_our_earth/aboutcc/problems/impacts/ (accessed July 9, 2014). Yoshihara, T., Naito, H., Kakigi, R., Ichinoseki-Sekine, N., Ogura, Y., Sugiura, T. & Katamoto, S. 2013. Heat stress activates the Akt/mTOR signalling pathway in rat skeletal muscle. Acta Physiol 207, 416–426. Yu, Y.B., Liao, Y.W., Su, K.H., Chang, T.M., Shyue, S.K., Kou, Y.R. & Lee, T.S. 2012. Prior exercise training alleviates the lung inflammation induced by subsequent exposure to environmental cigarette smoke. Acta Physiol 205, 532–540.
© 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd, doi: 10.1111/apha.12347
ExActa Extreme environments As a physiologist, one can often not help but marvel at the versatility of the mammalian body with regard to its adaptability to changing environments. In an earlier contribution to the Exacta series, we have discussed the latest developments in research on thermoregulation, introducing the tiny water bear (tardigrade), which is equipped with resources to not only withstand temperatures near absolute zero or centuries without any water, but also being shot into outer space (Persson & Persson 2012). With increasing structural complexity, organisms become, obviously, more restricted to certain environmental conditions. Mammals, nevertheless, survive and often thrive in environments ranging from tropical rainforests to eternal ice, but are, however, more limited than small eukaryotes when it comes to pressure, radiation or toxin exposure, to name but a few. Changing climatic conditions induce a change in the spectrum of mammals inhabiting certain regions of the globe (World Wildlife Fund 2014); mammals try to migrate or adapt – if they can (Schloss et al. 2012). But not only comparative physiologists are interested in the adaptability of organisms to environmental stress. Humans have climbed the highest mountains (Hunt 1953), dived in submarines to depths below 10,900 metres (Naval History & Heritage 2014), regularly look at the inside of active volcanoes (Solid Earth Science Working Group 2014) and reached the poles of the globe quite some time ago, let alone those who have left earth’s gravity. Following the headlinegenerating first explorations of these extreme environments, a current tendency towards the voluntary self-exposition to extreme environments for recreational purposes (and for showing off to one’s peers afterwards) is notable, as in: I can pay for it, so I am entitled to see/do/touch it – always aiming higher/deeper/further etc. Apart from these endeavours, limited exposition to challenging environments is used clinically, as in therapeutic hyperthermia, cryotherapy, chemotherapy or irradiation. Thus, the reaction of the human body or appropriately chosen animal models to extreme environments remains a current topic in physiological research. Underwater diving for leisure is a comparatively old activity (Richardson 1999), and not only the battle for ever-increasing depths fostered physiological research on that topic. The works of Tocco et al. (2013) and Marabotti et al. (2013) are especially relevant with
regard to current demographic developments, that is, an elderly, but still very active population. Responses to hyper-and hypothermic challenges are a classic topic in environmental physiology. Bain and co-workers (Bain et al. 2012) recently investigated the effect of hot fluid ingestion during physical activity and found that body heat storage is lower with warm water ingestion, possibly because of the activation of warm-sensitive thermosensors in the upper gastrointestinal tract. Fieger and Wong (Fieger & Wong 2012) have recently shed light on the mechanisms of thermoregulatory vasodilation during heat stress in humans. Further interesting findings have been reported by Yoshihara et al. (2013) on heat stress signalling, and by Machado-Moreira & Taylor (2012) on sudomotor response physiology. Hypothermia has recently been investigated by (Wold et al. 2013) with regard to myocardial calcium content in an in vivo rat model. Exposure to heights and the development of mountain sickness comprise, in contrast, a number of different stimuli. The role of the natriuretic peptide system in this pathology has been investigated thoroughly in (Woods et al. 2012). In a similar line, Kiviniemi et al. (2012) have investigated complex sympathoexcitatory manoeuvres to elicit the contribution of non-a-adrenergic mechanisms to systemic vascular conductance. Sudden-onset exercise may, in contrast to chronic training studies, also be seen as a challenging change of the environmental conditions that an individual undergoes. In this regard, Petersen et al. (2012) found a remarkable effect of antioxidant N-Acetylcysteine on acute exercise adaptation. Acute exercise exerts a number of interesting responses, among them a modulation of flow-mediated vascular responses to fluid shear stress (Llewellyn et al. 2012). Exposure to environmental toxins is a cluster of (often highly politicized) topics which, when considering the general image, is well beyond the reach of the physiologist alone. Nevertheless, certain toxins such as cigarette smoke (Cao et al. 2013) (Yu et al. 2012), hyperoxia (Micarelli et al. 2013) or hypercapnia (Taxini et al. 2013) fall within the physiologist’s realm. Keramidas et al. have demonstrated the effects of carbon monoxide during exercise performance (Keramidas et al. 2012) – by the way, did you cycle to the lab this morning? Acta Physiologica, although not specifically targeted to environmental or comparative physiology, continues
© 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd, doi: 10.1111/apha.12347
189
ExActa
· A Bondke Persson and P B Persson
to provide interesting data on environmental stimuli, and the reaction of the human/mammalian body to these, showing, in addition to scientific insight, how integrative physiology is very much alive.
Conflict of interest None.
A. Bondke Persson and P. B. Persson Institute of Vegetative Physiology, Charite-Universitaetsmedizin Berlin, Berlin, Germany E-mail: [email protected] References Bain, A.R., Lesperance, N.C. & Jay, O. 2012. Body heat storage during physical activity is lower with hot fluid ingestion under conditions that permit full evaporation. Acta Physiol 206, 98–108. Cao, L., Xu, C.B., Zhang, Y., Cao, Y.X. & Edvinsson, L. 2013. Secondhand cigarette smoke exposure causes upregulation of cerebrovascular 5-HT1B receptors via the Raf/ ERK/MAPK pathway in rats. Acta Physiol 207, 183–193. Fieger, S.M. & Wong, B.J. 2012. No direct role for A1/A2 adenosine receptor activation to reflex cutaneous vasodilatation during whole-body heat stress in humans. Acta Physiol 205, 403–410. Hunt, J. 1953. The Ascent of Everest. Hodder & Stoughton, London. Keramidas, M.E., Kounalakis, S.N., Eiken, O. & Mekjavic, I.B. 2012. Carbon monoxide exposure during exercise performance: muscle and cerebral oxygenation. Acta Physiol 204, 544–554. Kiviniemi, A.M., Frances, M.F., Rachinsky, M., Craen, R., Petrella, R.J., Huikuri, H.V., Tulppo, M.P. & Shoemaker, J.K. 2012. Non-alpha-adrenergic effects on systemic vascular conductance during lower-body negative pressure, static exercise and muscle metaboreflex activation. Acta Physiol 206, 51–61. Llewellyn, T.L., Chaffin, M.E., Berg, K.E. & Meendering, J.R. 2012. The relationship between shear rate and flowmediated dilation is altered by acute exercise. Acta Physiol 205, 394–402. Machado-Moreira, C.A. & Taylor, N.A.S. 2012. Sudomotor responses from glabrous and non-glabrous skin during cognitive and painful stimulations following passive heating. Acta Physiol 204, 571–581. Marabotti, C., Scalzini, A., Menicucci, D., Passera, M., Bedini, R. & L’Abbate, A. 2013. Cardiovascular changes during
190
Acta Physiol 2014, 212, 189–190 SCUBA diving: an underwater Doppler echocardiographic study. Acta Physiol 209, 62–68. Micarelli, A., Jacobsson, H., Larsson, S.A., Jonsson, C. & Pagani, M. 2013. Neurobiological insight into hyperbaric hyperoxia. Acta Physiol 209, 69–76. Naval History and Heritage. 2014. Dictionary of American naval fighting ships: Trieste. (online) Available at: http:// www.history.navy.mil/danfs/t8/trieste.htm (accessed July 9, 2014). Persson, A.B. & Persson, P.B. 2012. Getting a kick out of thermoregulation. Acta Physiol (Oxf) 204, 291–293. Petersen, A.C., McKenna, M.J., Medved, I., Murphy, K.T., Brown, M.J., Della Gatta, P. & Cameron-Smith, D. 2012. Infusion with the antioxidant N-acetylcysteine attenuates early adaptive responses to exercise in human skeletal muscle. Acta Physiol 204, 382–392. Richardson, D. 1999. A brief history of recreational diving in the United States. SPUMS J 29, 173–176. Schloss, C.A., Nu~ nez, T.A. & Lawler, J.J. 2012. Dispersal will limit ability of mammals to track climate change in the Western Hemisphere. Proc Natl Acad Sci USA 109, 8606–8611. Solid Earth Science Working Group. 2014. Nasa’s Research: Volcanoes. (online) Available at: http://solidearth.jpl.nasa. gov/PAGES/volc04.html (accessed July 9, 2014). Taxini, C.L., Puga, C.C.I., Dias, M.B., Bıcego, K.C. & Gargaglioni, L.H. 2013. Ionotropic but not metabotropic glutamatergic receptors in the locus coeruleus modulate the hypercapnic ventilatory response in unanaesthetized rats. Acta Physiol 208, 125–135. Tocco, F., Marongiu, E., Pinna, M., Roberto, S., Pusceddu, M., Angius, L., Migliaccio, G., Milia, R., Concu, A. & Crisafulli, A. 2013. Assessment of circulatory adjustments during underwater apnoea in elite divers by means of a portable device. Acta Physiol (Oxf) 207, 290–298. Wold, R.M., Kondratiev, T. & Tveita, T. 2013. Myocardial calcium overload during graded hypothermia and after rewarming in an in vivo rat model. Acta Physiol 207, 460–469. Woods, D.R., Begley, J., Stacey, M., Smith, C., Boos, C.J., Hooper, T., Hawkins, A., Hodkinson, P., Green, N. & Mellor, A. 2012. Severe acute mountain sickness, brain natriuretic peptide and NT-proBNP in humans. Acta Physiol 205, 349–355. World Wildlife Fund. 2014. The impacts of climate change on nature. (online) Available at: http://wwf.panda.org/about_our_earth/aboutcc/problems/impacts/ (accessed July 9, 2014). Yoshihara, T., Naito, H., Kakigi, R., Ichinoseki-Sekine, N., Ogura, Y., Sugiura, T. & Katamoto, S. 2013. Heat stress activates the Akt/mTOR signalling pathway in rat skeletal muscle. Acta Physiol 207, 416–426. Yu, Y.B., Liao, Y.W., Su, K.H., Chang, T.M., Shyue, S.K., Kou, Y.R. & Lee, T.S. 2012. Prior exercise training alleviates the lung inflammation induced by subsequent exposure to environmental cigarette smoke. Acta Physiol 205, 532–540.
© 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd, doi: 10.1111/apha.12347
