In vitro effect of. Delta. sup 9 -tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E sub 2
- Univ. of Texas Southwestern Medical Center at Dallas (United States)
- Centro de Estudios Farmacologicos y de Principios Naturales, Buenos Aires (Argentina)
Previous in vivo studies have shown that {Delta}{sup 9}-tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release. The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E{sub 2} (PGE{sub 2}) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE{sub 2} suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE{sub 2} synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release.
- OSTI ID:
- 5012945
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 87:24; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LH
INHIBITION
LH-RH
RADIOIMMUNOASSAY
MARIHUANA
BIOLOGICAL EFFECTS
STH
DOSE-RESPONSE RELATIONSHIPS
PROSTAGLANDINS
RATS
SOMATOSTATIN
ANIMALS
BIOASSAY
DIAGNOSTIC TECHNIQUES
GONADOTROPINS
HERBS
HORMONES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
LIBERINS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MAMMALS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PITUITARY HORMONES
PLANTS
PROTEINS
RADIOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
RODENTS
TRACER TECHNIQUES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics