Effects of acute and subchronic delta 9-tetrahydrocannabinol administration on the plasma catecholamine, beta-endorphin, and corticosterone levels and splenic natural killer cell activity in rats.
The effect of acute (1 day) or subchronic (25 days) treatment with delta 9-tetrahydrocannabinol (THC), the major psychoactive constituent of marihuana, on plasma norepinephrine (NE), epinephrine (E), corticosterone, beta-endorphin (beta-end), and splenic natural killer (NK) cell activity of the rat was studied. Groups of animals received subcutaneously, either THC in corn oil + saline (3 mg THC/kg); oil + saline; or THC + naloxone (2 mg naloxone/kg and 3 mg THC/kg). Acute injection of THC with or without naloxone did not significantly change plasma levels of NE, E corticosterone, beta-end, or the NK cell activity. However, subchronic treatment with THC significantly reduced plasma levels of NE, E, corticosterone, and NK cell activity, compared to controls. The plasma beta-end levels were significantly elevated in the THC-treated animals. In the THC + naloxone group of animals, the plasma hormone levels (corticosterone and beta-end) were similar to control levels and the NK cell activity was significantly higher than in THC-treated animals. These results indicate that subchronic exposure to THC results in suppression of splenic NK cell activity. The interaction of THC with the endogenous opiate system appears to be a contributing factor leading to the NK cell suppression in rats. A direct suppressive action of THC or its metabolites on the NK cell is not ruled out by this study.
D000818:Animals; D002395:Catecholamines / Q000097:blood*; D003345:Corticosterone / Q000097:blood*; D013759:Dronabinol / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D004723:Endorphins / Q000097:blood*; D007153:Immunologic Deficiency Syndromes / Q000139:chemically induced; D007279:Injections, Subcutaneous; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D008297:Male; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000166:cytology / Q000187:drug effects; D001615:beta-Endorphin
D002395:Catecholamines; D004723:Endorphins; D009270:Naloxone; D001615:beta-Endorphin; D013759:Dronabinol; D003345:Corticosterone