These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Extreme hyperthermia induced in cats by the enkephalin analog FK 33-824.
    Author: Clark WG, Bernardini GL, Ponder SW.
    Journal: Pharmacol Biochem Behav; 1982 Jun; 16(6):989-93. PubMed ID: 6287503.
    Abstract:
    FK 33-824 [H2N-Tyr-D-Ala-Gly-MePhe-Met(O)-OH] was injected into the third cerebral ventricle of unrestrained cats. Doses of 0.25-4 microgram induced dose-related increases in body temperature. Hyperthermic responses to 1 microgram of the peptide were greater the warmer the environment. Naloxone given intraventricularly 1 hr after FK 33-824 (1 microgram) reduced the hyperthermia. In 12 tests with six cats FK 33-824 (1-25 microgram) increased temperature 4.2-4.7 degrees C. These marked responses were also inhibited by naloxone, but two cats died when administration of antagonist was delayed for 80 min to 3 hr after attainment of maximal body temperature. Larger doses of FK 33-824 (50-250 microgram) evoked little increase in temperature, indicative of a separate action to depress thermoregulation. Although responses to FK 33-824 were antagonized by naloxone, this peptide, like another enkephalin analog D-Ala2-Met-enkephalinamide, must act on receptors which are not affected by morphine since (1) the hyperthermic response to FK 33-824 varied with environmental temperature, whereas the response to morphine does not, and (2) high doses of FK 33-824 depressed thermoregulation, an activity not shared by morphine in the cat. Furthermore, the maximal increases in temperature after FK 33-824 injection were greater than those evoked by either morphine or D-Ala2-Met-enkephalinamide. This observation provides evidence for an additional subset of naloxone-sensitive, v, receptors, stimulation of which can influence thermoregulation in the cat.
    [Abstract] [Full Text] [Related] [New Search]