The facilitating and suppressing effects of delta 9-tetrahydrocannabinol on the rise in intrasynaptosomal Ca2+ concentration in rats.
The effects of delta 9-tetrahydrocannabinol (delta 9-THC) on the rise in intracellular Ca2+ concentrations ([Ca2+]i) after stimulation with 15 mM or 29 mM K+ in rat whole brain synaptosomes were examined. A fluorescent chelating agent, Rhod-2, was employed to monitor any alterations of K(+)-evoked [Ca2+]i. Pretreatment with 10(-10) M delta 9-THC for 3 min enhanced K(+)-evoked [Ca2+]i significantly, while 10(-9), 10(-8) or 5 x 10(-8) M delta 9-THC significantly inhibited the K(+)-evoked [Ca2+]i. These results suggest that delta 9-THC had a biphasic effect on the K(+)-evoked Ca2+ response in rat brain synaptosomes.
Okada
M
M
Department of Physiology and Pharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
Urae
A
A
Mine
K
K
Shoyama
Y
Y
Iwasaki
K
K
Fujiwara
M
M
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000494:pharmacology*; D005456:Fluorescent Dyes; D006575:Heterocyclic Compounds, 3-Ring; D007700:Kinetics; D051381:Rats; D013050:Spectrometry, Fluorescence; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D005456:Fluorescent Dyes; D006575:Heterocyclic Compounds, 3-Ring; C068483:rhod-2; D013759:Dronabinol; D002118:Calcium