Distinct vasopressin content in the hypothalamic supraoptic and paraventricular nucleus of rats exposed to low and high ambient temperature.
Both high and low ambient temperature represent thermal stressors that, among other physiological responses, induce activation of the hypothalamic-pituitary-adrenal (HPA) axis and secretion of arginine-vasopressin (AVP). The exposure to heat also leads to disturbance of osmotic homeostasis. Since AVP, in addition to its well-known peripheral effects, has long been recognized as a hormone involved in the modulation of HPA axis activity, the aim of the present study was to elucidate the hypothalamic AVP amount in the acutely heat/cold exposed rats. Rats were exposed to high (+38°C) or low (+4°C) ambient temperature for 60min. Western blot was employed for determining hypothalamic AVP levels, and the difference in its content between supraoptic (SON) and paraventricular nucleus (PVN) was detected using immunohistochemical analysis. The results showed that exposure to both high and low ambient temperature increased hypothalamic AVP levels, although the increment was higher under heat conditions. On the other hand, patterns of AVP level changes in PVN and SON were stressor-specific, given that exposure to cold increased the AVP level in both nuclei, while heat exposure affected the PVN AVP content alone. In conclusion, our results revealed that cold and heat stress influence hypothalamic AVP amount with different intensity. Moreover, different pattern of AVP amount changes in the PVN and SON indicates a role of this hormone not only in response to heat as an osmotic/physical threat, but to the non-osmotic stressors as well.
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia; Center for Laser Microscopy, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia. Electronic address: jasnicn@bio.bg.ac.rs.
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Jasnic
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Dakic
Center for Laser Microscopy, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Bataveljic
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Vujovic
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Lakic
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Jevdjovic
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Djurasevic
Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
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Djordjevic
D000818:Animals; D003080:Cold Temperature; D004777:Environment; D006358:Hot Temperature; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007032:Hypothalamus, Anterior / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D010913:Pituitary-Adrenal System / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000502:physiology; D013696:Temperature; D014667:Vasopressins / Q000378:metabolism*
D014667:Vasopressins
Cold; HPA axis; Heat; Hypothalamus; Vasopressin