Neuroactive steroids modulate in vitro the Mg(2+)-dependent Ca(2+)-ATPase activity in cultured rat neurons.
1. The in vitro effect of neuroactive steroids on the Mg(2+)-dependent Ca(2+)-ATPase activity in neuronal membranes isolated from primary cell culture of rat cortex was examined. 2. A 1-hr treatment of neuronal cell culture with 17-beta-estradiol (10 pM) and pregnenolone sulfate (1 microM) resulted in an increase in the enzyme activity of as much as 130% and 160%, respectively. 3. Neuroactive steroids moderately decreased the stimulation of the Mg(2+)-dependent Ca(2+)-ATPase activity by 72 nM calmodulin, by 20-30%. 4. The effects of hormones on the ATPase activity were irreversible after extensive washing of the membranes. 5. These results suggest that 17-beta-estradiol and pregnenolone sulfate at physiological concentrations could participate in the regulation of neuronal calcium homeostasis at a membrane level.
Zylińska
L
L
II Department of Biochemistry, Medical University, Lódź, Poland.
Legutko
B
B
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000187:drug effects* / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology; D004789:Enzyme Activation; D004958:Estradiol / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D011284:Pregnenolone / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
C018370:pregnenolone sulfate; D004958:Estradiol; D011284:Pregnenolone; D000252:Calcium-Transporting ATPases