Release of an active sodium transport inhibitor (ASTI) from rat hypothalamic cells in culture.
To investigate the hypothesis whether the hypothalamus releases an active (ouabain-sensitive) sodium transport inhibitor, we cultured hypothalamic and cortical cells from day 17 fetal rats. Culture media from hypothalamic cells reduced the total erythrocyte sodium efflux rate constant from 0.487 +/- (SE) 0.014 to 0.408 +/- 0.013 (P less than 0.001), and the ouabain-sensitive rate constant from 0.305 +/- 0.015 to 0.240 +/- 0.016 (P less than 0.01). Hypothalamic media also showed a dose-dependent displacement of [3H]-ouabain-binding to erythrocyte membranes. Neither cortical nor conditioned media (incubated without cells) had any effect. Various well-characterized hormones of hypothalamic origin failed to inhibit sodium efflux rate constant. These studies demonstrate that fetal rat hypothalamic cells contain and release a factor which inhibits sodium transport in human erythrocytes.
D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000166:cytology*; D010042:Ouabain / Q000378:metabolism; D010455:Peptides; D011188:Potassium / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D012964:Sodium / Q000037:antagonists & inhibitors* / Q000097:blood / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D013004:Somatostatin / Q000378:metabolism
D003470:Culture Media; D010455:Peptides; C029311:serum sodium transport inhibitor; D013004:Somatostatin; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium; D002118:Calcium