title: Uptake and metabolism of female sex steroids by isolated small neurons and other cell fractions from the rat medial basal hypothalamus.
abstract: Rat medial basal hypothalami (MBH) and sections of cerebral cortex (CC) were dissociated with trypsin to prepare single cells and subcellular fractions. They were then separated into four fractions on a discontinuous sucrose gradient. The small neurons in Fraction D were highly purified. Fraction A had synaptosomes, myelin and other cell particulates. Fraction B had glial cells, neurons and a few synaptosomes. Fraction C had large neurons and red blood cells. All four fractions contained LHRH, but most (62.5%) of this hormone was present in Fraction A. Dissociated cell suspensions were incubated with [3H]-steroids, with and without a 100-fold excess of unlabeled steroids, then separated on sucrose gradients. In most fractions the total uptake and specific uptake of [3H]-progesterone, [3H]-5 alpha-pregnane-3,20-dione (5 alpha-dihydroprogesterone) and [3H]-17 beta-estradiol were greater for the dissociated cells from the MBH than the CC. The dissociated cells and cell particulates in all four fractions from the MBH and CC metabolized progesterone, 5 alpha-dihydroprogesterone and 17 beta-estradiol. These results indicate that hypothalamic neurons contain small amounts of LHRH and retain the ability to take up and metabolize progesterone, 5 alpha-dihydroprogesterone and 17 beta-estradiol.
mesh_terms: D004092:20-alpha-Dihydroprogesterone / Q000378:metabolism; D000818:Animals; D002469:Cell Separation; D002540:Cerebral Cortex / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D049671:History, 18th Century; D007031:Hypothalamus / Q000378:metabolism*; D007033:Hypothalamus, Middle / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D011280:Pregnanolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism*; D051381:Rats; D013574:Synaptosomes / Q000378:metabolism
chemical_list: D004092:20-alpha-Dihydroprogesterone; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D011280:Pregnanolone