Role of 5-hydroxytryptamine in ketamine-induced hypothermia in the rat

I Fahim, M Ismail, O H Osman, I Fahim, M Ismail, O H Osman

Abstract

1. Intraperitoneal injection of graded doses of ketamine produced a dose-dependent fall in body temperature of rats. Similarly, intracerebral injection of much smaller doses produced hypothermia.2. Pretreatment of the rats with p-chlorophenylalanine (PCPA) greatly attenuated the hypothermic response to ketamine whereas the intraperitoneal injection of 5-hydroxytryptophan in PCPA-treated rats restored the hypothermic effect of ketamine.3. Depletion of the brain monoamines by reserpine completely prevented the ketamine-induced hypothermia. Treatment with sodium diethyldithiocarbamate (DEDTC), however, did not modify the hypothermic effect of ketamine.4. Pretreatment of the rats with pargyline potentiated the ketamine-induced hypothermia.5. Depletion of brain monoamines by reserpine in combination with inhibition of noradrenaline biosynthesis (DEDTC) resulted in a long lasting fall in temperature which was not modified by ketamine.6. When the ambient temperature was raised from 26 degrees C to 32 degrees C, ketamine-induced hypothermia was much reduced and superimposed on a hyperthermia which occurred in all animals.7. It is concluded that ketamine produces hypothermia in rats possibly through the release of 5-hydroxytryptamine in the hypothalamus and that this effect is similar in some respects to that produced by morphine in non-tolerant rats.

References

    1. J Physiol. 1964 Sep;173:226-31
    1. Br J Pharmacol. 1969 Oct;37(2):400-13
    1. Br J Pharmacol. 1970 Jan;38(1):157-70
    1. Med Pharmacol Exp Int J Exp Med. 1967;17(6):576-85
    1. Nature. 1963 Dec 28;200:1325
    1. Anesthesiology. 1967 Sep-Oct;28(5):823-33
    1. J Pharmacol Exp Ther. 1956 Jan;116(1):84-9
    1. J Pharmacol Exp Ther. 1966 Dec;154(3):499-516
    1. J Neurochem. 1956 May;1(1):8-11
    1. J Physiol. 1967 May;190(1):203-20
    1. Can J Biochem Physiol. 1958 Dec;36(12):1243-9
    1. J Physiol. 1964 Dec;175:464-78
    1. J Pharm Pharmacol. 1965 Aug;17(8):526-7
    1. Br J Pharmacol Chemother. 1967 Sep;31(1):152-61
    1. Eur J Pharmacol. 1970 Feb;9(2):183-9
    1. Neuropharmacology. 1970 May;9(3):277-82
    1. J Pharmacol Exp Ther. 1972 Jan;180(1):136-43
    1. J Physiol. 1966 Oct;186(2):416-23
    1. J Pharm Pharmacol. 1966 Jan;18(1):60-2

Source: PubMed

Sponsorer og samarbeidspartnere

Medisinsk tilstand

Legemiddelintervensjoner

3
Abonnere