Abstract
The effect of morphine sulfate on the body temperature of the rat has been investigated. With a dose of 10 mg/kg administered intravenously there occurred a marked fall in core temperature and the degree and duration of hypothermia increased to give a maximum response with 35-50 mg/kg. Doses of 1 and 5 mg/kg caused either no change or a rise in temperature.
Injection of 50 µg morphine sulfate into the region of the preoptic/anterior hypothalamic nuclei also led to a fall in core temperature, while injections into other regions of the hypothalamus were ineffective. Introduction of the drug into the area of the mammillary nuclei caused hyperactivity and hyperthermia.
It is suggested that the hypothermic effect of morphine is due to depression of the set point of the thermoregulatory center in the anterior hypothalamus.
Footnotes
- Accepted May 18, 1965.
- The Williams & Wilkins Comapny
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|