Effect of 5,7-dihydroxytryptamine, ovariectomy and gonadal steroids on serotonin receptor binding in rat brain.
Quantitative autoradiography was used to assess alterations in serotonin (5-HT) receptor binding in the hypothalamus and hippocampus following denervation with 5,7-dihydroxytryptamine (5,7-DHT), ovariectomy (OVX) and gonadal steroid manipulation. Seven days after 5,7-DHT injection, 5-HT1a receptor density was significantly increased in the ventromedial hypothalamic nucleus (VMN) of intact but not OVX female rats. Under these conditions 5-HT1b receptor density was unchanged in any brain region examined and 5-HT transporter binding was decreased in all 5,7-DHT injected animals. In addition, there was a significant interaction between OVX and 5,7-DHT for both the 5-HT1a receptor and the 5-HT transporter in the VMN, such that OVX inhibited the 5,7-DHT-induced increase in 5-HT1a receptors and attenuated the 5,7-DHT-induced decrease in 5-HT transporter binding. In a separate experiment the effect of gonadal steroid manipulation on 5-HT receptor binding was assessed. In female OVX rats, 5-HT1a receptor density was unchanged by estrogen or estrogen and progesterone administration. In male rats, castration significantly decreased 5-HT1a receptor density in the medial preoptic area. Estrogen and progesterone administration to female OVX rats increased the density of 5-HT1b receptors in the VMN, as compared to estrogen alone. The relationship of these results to the role of 5-HT in mediating lordosis behavior is discussed.
Frankfurt
M
M
Rockefeller University, New York, NY 10021.
McKittrick
C R
CR
Mendelson
S D
SD
McEwen
B S
BS
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology*; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000493:pharmacokinetics; D000818:Animals; D001345:Autoradiography; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D020120:Iodocyanopindolol; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009919:Orchiectomy; D010052:Ovariectomy; D017374:Paroxetine / Q000493:pharmacokinetics; D010869:Pindolol / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D011374:Progesterone / Q000494:pharmacology; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D050486:Serotonin Plasma Membrane Transport Proteins; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism
D002352:Carrier Proteins; D004967:Estrogens; D012739:Gonadal Steroid Hormones; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011985:Receptors, Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; C493232:Slc6a4 protein, rat; D015116:5,7-Dihydroxytryptamine; D017374:Paroxetine; D011374:Progesterone; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D020120:Iodocyanopindolol; D010869:Pindolol