Copper amplification of prostaglandin E/sub 2/ stimulation of the release of luteinizing hormone-releasing hormone is a postreceptor event
The authors have shown that copper amplifies prostaglandin E/sub 2/ (PGE/sub 2/) stimulation of luteinizing hormone-releasing hormone (LH-RH) from explants of the median eminence area (MEA) and that this process is calcium-dependent. Since a Ca-cAMP pathway has been implicated in PGE/sub 2/ action on the LH-RH neuron, in this study the authors wished to ascertain if copper exerts its effect on the PGE/sub 2/ receptor or on a postreceptor component involved in PGE/sub 2/ action. MEA of adult male rats were incubated for 5 min with 200 ..mu..M Cu/histidine and then incubated for 15 min either with 10 ..mu..M PGE/sub 2/ (Cu/PGE/sub 2/), 100 ..mu..M forskolin (Cu/forskolin), or 1 mM 8-bromoadenosine 3',5'-cyclic monophosphate (Cu/cAMP). Basal release of LH-RH was 4.6 +/- 0.45 pg/15 min per MEA determined by radioimmunoassay. Net stimulated release during the 15-min exposure to PGE/sub 2/, forskolin, or 8-bromoadenosine 3',5'-cyclic monophosphate was 3.6 +/- 0.52, 3.1 +/- 0.39, and 1.6 +/- 0.42 pg/15 min per MEA, respectively. Net stimulated release after exposure to Cu/PGE/sub 2/, Cu/forskolin, or Cu/cAMP indicated that copper amplifies the action of PGE/sub 2/ and forskolin but not cAMP action. When MEA were exposed to a mixture of PGE/sub 2/ and forskolin for 15 min, the effects of these two secretagogues on LH-RH release were not additive. In contrast to PGE/sub 2/ and forskolin, copper did not amplify K/sup +/ stimulation of OH-RH release. These results are supportive of the proposition that PGE/sub 2/ stimulation of OH-RH release is mediated by the Ca-cAMP pathway and that copper amplification of PGE/sub 2/ action is a postreceptor event.
- Research Organization:
- Univ. of Texas Health Science Center, Dallas
- OSTI ID:
- 6243163
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 84:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
COPPER CHLORIDES
BIOLOGICAL EFFECTS
LH-RH
RADIOIMMUNOASSAY
PROSTAGLANDINS
BIOCHEMISTRY
ADULTS
AMP
BIOLOGICAL PATHWAYS
DOSE-RESPONSE RELATIONSHIPS
HISTIDINE
MALES
RATS
AGE GROUPS
AMINO ACIDS
ANIMALS
AZOLES
CARBOXYLIC ACIDS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
COPPER COMPOUNDS
COPPER HALIDES
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HORMONES
IMIDAZOLES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
LIBERINS
MAMMALS
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDE HORMONES
PITUITARY HORMONES
RADIOASSAY
RADIOIMMUNOLOGY
RODENTS
TRACER TECHNIQUES
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics
560300 - Chemicals Metabolism & Toxicology