THE EFFECTS OF PRENATALLY ADMINISTERED ENDOGENOUS CANNABINOID ON RAT OFFSPRING

WENGER, T., G. FRAGKAKIS, P. GIANNIKOU AND N. YIANNIKAKIS. The effects of prenatally administered endogenous cannabinoid on mt offspring. PH ARMACOL BIOCHEM BEHAV 58(2) 537-544, 1997.--We reported previously tha t the main psychoactive component of marihuana, Delta(9) tetrahydrocan nabinol (THC), when injected prenatally, temporarily inhibited the dev eloping hypothalamo-pituitary system in rat offspring. In the present study, we investigated the effects of the recently described endogenou s ligand for the central cannabinoid receptor, arachidonyl-ethanolamid e (anandamide, ANA), on the postnatal development of the hypothalamo-p ituitary axis (HPA) when administered during the third week of gestati on. Rat pups were killed every fifth day from delivery to the 20th pos tnatal day; gonads, pituitary, and rest of body were weighed, and samp les were collected for analysis of gonadotropin releasing hormone in t he hypothalamus and luteinizing hormone, follicle stimulating hormone, prolactin, and growth hormone in the pituitaries and sera. The effect s of ANA and THC were compared. Both ANA and THC caused predominantly inhibitory effects on the measured parameters. The inhibition was most pronounced immediately following delivery, whereas at the end of the investigated period (20th postnatal day) no differences were observed. We conclude that endogenous and exogenous cannabinoids have similar b ut slightly different effects on the developing HPA and that the actio n is transitory. We postulate that ANA probably acts via central canna binoid receptors and/or neuroendocrine receptors to function as a neur omodulator. (C) 1997 Elsevier Science Inc.