Summary
Thermoregulatory reactions evoked by selective preoptic-anterior hypothalamic (PO/AH) heating in conscious rabbits were associated with significant changes in renal function. Urine flow rate decreased from a control value of 0.92±(S.E.) 0.08 to 0.47±0.07 ml/min after 10–20 min of heating, urine osmolality increased from 273±34 to 417±46 Osm/kg H2O, and free water clearance per 100 ml GFR decreased from 1.11±0.46 to −0.50±0.23 ml/min. These changes were followed by a gradual recovery despite continued heating. Clearances of exogenous creatinine and p-aminohippurate fell transiently during the first 10 min of heating and then returned to normal.
Plasma antidiuretic activity (ADA) measured by rat bioassay increased regularly and markedly during PO/AH heating but was poorly correlated with changes in urine concentration. Moreover, a similar increase in plasma ADA observed with selective heating of a different brain area (supraoptic nucleus) never produced urine concentration or other renal changes. This suggests that a large and variable fraction of ADA appearing in rabbit blood in response to thermal stimuli was not identical with antidiuretic hormone. Therefore, the causal relationship of ADH release and antidiuresis associated with thermoregulatory reactions could not be clearly demonstrated. The physiological role of renal water conservation would be to compensate for extrarenal water loss related to thermal sweating or panting.
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Cowley, A. W., Jr., Mons, E., Guyton, A. C.: Interaction of vasopressin and the baroreceptor reflex system in the regulation of arterial blood pressure in the dog. Circulat. Res.34, 505–514 (1974)
Czaczkes, J. W., Kleeman, C. R., Koenig, M.: Physiologic studies of antidiuretic hormone by its direct measurement in human plasma. J. clin. Invest.43, 1625–1640 (1964)
Fifková, E., Maršala, J.: Stereotaxic atlas for the cat, rabbit and rat brains. Prague: State Medical Publishers 1960
Iriki, M., Riedel, W., Simon, E.: Regional differentiation of sympathetic activity during hypothalamic heating and cooling in anesthetized rabbits. Pflügers Arch.328, 320–331 (1971)
Kozlowski, S., Szczepańaka-Sadowska, E., Drzewiecki, K.: Plasma ADH changes in human subjects exposed to high ambient temperature (in Polish). Pol. Arch. intern Med.48, 251–256 (1971)
Kruk, B. Davydov, B.: Effect of ambient temperature on thermal sensitivity of POAH area in the rabbit. J. Thermal Biol. (in press, 1977)
Radigan, L. R., Robinson, S.: Effects of environmental heat stress and exercise on renal blood flow and filtration rate. J. appl. Physiol.2, 185–191 (1949)
Rowell, L. B., Bengelmann, G. L., Blackmon, J. R., Murray, J. A.: Redistribution of blood flow during sustained high skin temperature in resting man. J. appl. Physiol.28, 415–420 (1970)
Sadowski, J., Szreder, I., Sternik-Sagalara, K.: Indirect sodium-retaining action of oxytocin on dog kidney. Proc. Soc. exp. Biol. (N. Y.)128, 294–300 (1968)
Schönung, W., Wayner, H., Jessen, C., Simon, E. Regional blood flow antagonism induced by central thermal stimulation in the conscious dog. Experientia (Basel)27, 1291–1292 (1971)
Schönung, W., Wayner, H., Jessen, C., Simon, E.: Differentiation of cutaneous and intestinal blood flow during hypothalamic heating and cooling in anesthetized dogs. Pflügers Arch.328, 145–154 (1971)
Segar, W. E., Moore, W. W.: The regulation of antidiuretic hormone-release in man. I. Effect of change in position and ambient temperature on blood ADH levels. J. clin. Invest.47, 2143–2151 (1968)
Szczepańska-Sadowska, E., Hemodynamic effects of a moderate increase of the plasma vasopressin level in conscious dogs. Pflügers Arch.338, 313–322 (1973)
Szczepańska-Sadowska, E., Sadowski, B.: Antidiuretic assay for vasopressin. Acta physiol. pol.24, 479–483 (1973)
Szczepańska-Sadowska, E.: Plasma ADH increase and thirst suppression elicited by preoptic heating in the dog. Amer. J. Physiol.226, 155–161 (1974)
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Sadowski, J., Kruk, B., Chwalbińska-Moneta, J. et al. Renal function changes during preoptic-anterior hypothalamic heating in the rabbit. Pflugers Arch. 370, 51–57 (1977). https://doi.org/10.1007/BF00707945
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DOI: https://doi.org/10.1007/BF00707945