Central injection of a sigma opioid receptor agonist alters body temperature of cats.
The prototype sigma opioid receptor agonist N-allyl-normetazocine (SKF 10,047) was injected into the third cerebral ventricle of conscious, unrestrained cats, and their temperature was monitored automatically from the retroperitoneal space. In a cold environment (0 degrees C) a small, but not dose-related, hypothermia occurred after doses of 100-500 micrograms. This response was not antagonized by naloxone given intraventricularly either 15 min before or 1 hr after the opioid. A smaller hypothermia resulted after 250 micrograms SKF 10,047 when the environmental temperature was 22 degrees C, whereas hyperthermia developed in a hot environment (34 degrees C). Thus SKF 10,047 appears to allow body temperature to drift, upward in the heat and downward in the cold, a pattern indicative of thermoregulatory depression. These results are similar to those obtained in the first 2-3 hr after pentazocine administration, and they support a previous classification of the initial temperature response to centrally injected pentazocine as due to stimulation of sigma opioid receptors.
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D010423:Pentazocine / Q000494:pharmacology; D010620:Phenazocine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects*
D011957:Receptors, Opioid; C012134:SK&F 10047; D010620:Phenazocine; D010423:Pentazocine