Neurons from fetal rat brains contain functional luteinizing hormone/chorionic gonadotropin receptors.
Adult and neonatal rat brains contain functional LH/hCG receptors. These findings have led us to hypothesize that the fetal rat brain may also contain these receptors. To test this hypothesis, we isolated neurons from 19-day-old fetal rat brains and cultured them in chemically defined serum-free medium. The reverse transcription polymerase chain reaction amplified an expected 256-base pair size LH/hCG receptor fragment that could hybridize with a full-length LH/hCG receptor cDNA in Southern blotting. Northern blotting demonstrated that neurons contained a major 2.6 kilobase (kb) and a minor 4.3 kb transcript. Immunocytochemistry demonstrated that the neurons contained LH/hCG receptor immunostaining. Western immunoblotting showed that neurons contained an 80-kDa receptor protein that increased to a maximal level on Day 3 of culture and then gradually decreased until the 9th day of culture. Culturing neurons for 3 days in the presence of highly purified hCG resulted in a dose-dependent increase in the outgrowth of neurite processes and total cellular protein and a decrease in DNA fragmentation as compared to values in the corresponding controls. At the maximally effective hCG concentration, the number of neurite-bearing cells was increased by 53% and the total cellular protein by 60%, and DNA fragmentation decreased by 31%. In summary, this is the first study to demonstrate the presence of LH/hCG receptors and neurotrophic effects of hCG in fetal rat brain neurons. These findings imply that locally produced gonadotropins may possibly play a role in the growth and development of the fetal brain.
AL-Hader
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AA
Department of Physiology and Biochemistry, Jordan University of Science and Technology, Irbid.
Lei
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ZM
Rao
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D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005333:Fetus / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011974:Receptors, LH / Q000235:genetics / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D017931:DNA Primers; D012333:RNA, Messenger; D011974:Receptors, LH