Effect of chronic administration of delta 9-tetrahydrocannabinol on the endogenous opioid peptide and catecholamine levels in the diencephalon and plasma of the rat.
The effect of chronic administration of delta 9-tetrahydrocannabinol (delta 9-THC) on the endogenous opiate and catecholamine levels was investigated. Intact male rats were injected daily either with vehicle (50 microliters oil) or delta 9-THC in oil (3 mg delta 9-THC/kg body wt). The treatments were administered subcutaneously over a period of 25 days. All animals were decapitated after the last injection and trunk plasma was assayed for prolactin, beta-endorphin-like immunoreactivity (beta-end LI), norepinephrine (NE), epinephrine (E), dihydroxyphenyl acetic acid (DOPAC) and dopamine (DA). The preoptic area (POA) and medial basal hypothalamus were assayed for methionine enkephalin, beta-endorphin and catecholamines. Chronic delta 9-THC treatment resulted in an increase in POA and MBH methioine-enkephalin and beta-end LI as well as an increase in plasma beta-end LI. The POA, MBH and plasma NE and E levels were lower in these animals when compared with the controls. In the MBH, however, the delta 9-THC treated rats contained higher DA and DOPAC levels when compared with the controls. These results support our view that chronic delta 9-THC administration alters the activities of the endogenous opiate system as well as the catecholaminergic system and consequently impairs the endocrine functions.
D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D013759:Dronabinol / Q000494:pharmacology*; D004723:Endorphins / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D007033:Hypothalamus, Middle / Q000187:drug effects; D008297:Male; D011301:Preoptic Area / Q000187:drug effects; D011388:Prolactin / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects*; D001615:beta-Endorphin
D002395:Catecholamines; D004723:Endorphins; D011957:Receptors, Opioid; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D013759:Dronabinol; D011388:Prolactin