Richter R, Oehme P, Marten F T, Bienert M
Pharmazie. 1982 Feb;37(2):134-6.
Various peptides have been shown to alter body temperature. Intraperitoneal administration of substance P (SP) in doses of 25 and 250 micrograms/kg produces a significant hypothermic response in normotensive rats under cold exposure at 4 degrees C, whereas a dose of 2.5 micrograms/kg causes an increase in body temperature. Pretreatment with naloxone (4 mg/kg, 30 min before SP) suppresses the hypothermic effect. In spontaneously hypertensive rats (SHR), however, SP does not alter the body temperature. This result points to an altered thermoregulation in SHR based on changes in endorphin systems.
