AJP - Regulatory, Integrative and Comparative Physiology, Vol 241, Issue 5 271-R276, Copyright © 1981 by American Physiological Society
Endogenous cryogen excreted by the kidneys
M. J. Kluger, A. J. Turnbull, W. I. Cranston, A. J. Wing, M. P. Gross and B. A. Rothenburg
Injection (iv) of human urine into rabbits results in a fall in body
temperature accompanied by peripheral vasodilation in a thermoneutral
ambient temperature and suppression of shivering metabolism in the cold.
There were no consistent changes in mean arterial pressure in response to
the injection of urine. If the production of urine is prevented by
occlusion of the ureters of rabbits, body temperature falls. Injection of
endogenous pyrogen (iv) into rabbits, which have had their ureters
occluded, results in a significant attenuation in the magnitude of the
fever as compared to controls. These observations suggest that there is an
endogenously produced cryogenic substance ("endogenous cryogen") normally
excreted in an active form by the kidneys and which when either injected,
or prevented from being excreted (by clamping the ureters), results in a
regulated fall in body temperature. In addition, in human patients on
regular dialysis treatment who still had residual renal function, the oral
temperature was slightly below normal before hemodialysis and slightly
above normal after hemodialysis, a difference averaging 0.39 degrees C (P
less than 0.001). These data are in agreement with the hypothesis that
endogenous cryogen is a dialyzable substance, and that its concentration is
reduced (and therefore the patient's body temperature rises) during
hemodialysis.
