Protein deficiency: its effects on body temperature in health and disease states.

Little is known about the effects of protein malnutrition on the ability to regulate body temperature during health and disease. To investigate this area, we placed young rabbits on a low-protein diet and recorded their body temperatures. There were no differences between the protein-deprived and control animals concerning their abilities to maintain constant body temperatures during exposure to low (5 C, 10 C) and thermoneutral ambient temperature (20 C). In a warm ambient temperature (30 C) the protein-deprived animals were actually better able to maintain a lower body temperature. Injections with heat killed bacteria led to little or no fever in the protein-deprived group. However, intravenous injections of endogenous pyrogen, a protein mediator of fever, resulted in fevers virtually identical to that attained in control animals. These data indicate that the attenuated febrile response to bacterial injection during protein deprivation may be due to a diminished production of endogenous pyrogen, and not to some alteration in the central nervous system sensitivity to pyrogens.