The density of 5-hydoxytryptamine2A receptors in forebrain is increased at pro-oestrus in intact female rats.
We have shown previously that in ovariectomised rats, oestradiol-17beta, in its positive-feedback mode for luteinizing hormone (LH) release, induces a significant increase in the density of 5-hydroxytryptamine2A (5-HT2A) receptors in the forebrain. Here we investigated whether there are any changes in 5-HT2A receptor density in relation to the spontaneous surge of oestradiol-17beta in female COB Wistar rats between dioestrus and pro-oestrus. Using [3H]RP62203-binding and autoradiography, we found that 5-HT2A binding sites were significantly increased at 1630-1800 h on pro-oestrus compared with 0900-1130 h on dioestrus in frontal and cingulate cortex, olfactory tubercle and nucleus accumbens. The densities of 5-HT2A binding sites in male rats were similar to dioestrous female values in cortex, and to pro-oestrous female values in nucleus accumbens. The changes in the density of 5-HT2A binding sites in the forebrain of female rats may be relevant to oestrogen effects on mood and mental state.
Sumner
B E
BE
MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh, UK. bsumner@srv1.bmu.mrc.ac.uk
Fink
G
G
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D007091:Image Processing, Computer-Assisted; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D011359:Proestrus / Q000378:metabolism*; D016548:Prosencephalon / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000378:metabolism*; D012636:Secretory Rate; D012727:Sex Characteristics
D011985:Receptors, Serotonin; D007986:Luteinizing Hormone