Inhibition by oxytocin of voltage-activated calcium influx in cultured PC12 pheochromocytoma cells.
1. Voltage-activated dihydropyridine-sensitive Ca2+ influx was measured in PC12 pheochromocytoma cells using 45Ca. 2. It has been found that oxytocin inhibits voltage-activated dihydropyridine-sensitive Ca2+ influx with ED50 about 0.30 x 10(-6) M. 3. Tolbutamide (1.3 x 10(-3) M) has no visible effect on both Ca2+ influx itself and on the inhibitory oxytocin effect. 4. External application of Li+ (10 mM) causes a slight shift of ED-curve to lower oxytocin concentrations. 5. It is suggested that the hydrolysis of phosphoinositides may play a role in oxytocin action on Ca2+ influx in PC12 cells.
Kolchinskaya
L I
LI
A. A. Bogomoletz Institute of Physiology, Ukrainian Academy of Sciences, Kiev, U.S.S.R.
Kononenko
N I
NI
Pogorelaya
N C
NC
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000310:Adrenal Gland Neoplasms / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000493:pharmacokinetics; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009568:Nitrendipine / Q000494:pharmacology; D010673:Pheochromocytoma / Q000378:metabolism* / Q000473:pathology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D015290:Second Messenger Systems / Q000502:physiology; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009568:Nitrendipine; D008094:Lithium; D011188:Potassium; D002118:Calcium