Abstract
We compared the effects of Phospholipases A2, C, B and D on [3H]nitrendipine binding to hamster cardiac membranes, in the absence and presence of ATP or GTP. Phospholipase A2, competitively inhibited [3H]nitrendipine binding to hamster cardiac membranes unchanged by ATP or GTP (Ki = 5 ng/ml); as evidenced by complete and reversible displacement of [3H]nitrendipine binding and increase in KD on Scatchard analyses. Phospholipase C also completely inhibited [3H]nitrendipine binding to hamster cardiac membranes (Ki = 5 ug/ml) with a decrease in Bmax and no change in KD on Scatchard analyses. The addition of GTP alone inhibited the PLC effect in EGTA-treated membranes. The addition of GTP with either CaCl2, or ATP or both resulted in an equal and opposite enhancement of the PLC effect. Phospholipases B and D had no effect on [3H]nitrendipine binding. These data support: (1) Direct effect of PLA2 on dihydropyridine binding. (2) Indirect regulation of dihydropyridine binding by Phospholipase C through a GTP and ATP-sensitive mechanism.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1031-1041 |
| Number of pages | 11 |
| Journal | Life Sciences |
| Volume | 50 |
| Issue number | 14 |
| DOIs | |
| State | Published - 1992 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Pharmacology
Cite this
Regulation of [3H]nitrendipine binding by phospholipases A2 and C through direct and GTP-sensitive mechanisms. / Finkel, Mitchell S.; Hartsell, Theresa L.; Oddis, Carmine V.
In: Life Sciences, Vol. 50, No. 14, 1992, p. 1031-1041.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Regulation of [3H]nitrendipine binding by phospholipases A2 and C through direct and GTP-sensitive mechanisms
AU - Finkel, Mitchell S.
AU - Hartsell, Theresa L.
AU - Oddis, Carmine V.
PY - 1992
Y1 - 1992
N2 - We compared the effects of Phospholipases A2, C, B and D on [3H]nitrendipine binding to hamster cardiac membranes, in the absence and presence of ATP or GTP. Phospholipase A2, competitively inhibited [3H]nitrendipine binding to hamster cardiac membranes unchanged by ATP or GTP (Ki = 5 ng/ml); as evidenced by complete and reversible displacement of [3H]nitrendipine binding and increase in KD on Scatchard analyses. Phospholipase C also completely inhibited [3H]nitrendipine binding to hamster cardiac membranes (Ki = 5 ug/ml) with a decrease in Bmax and no change in KD on Scatchard analyses. The addition of GTP alone inhibited the PLC effect in EGTA-treated membranes. The addition of GTP with either CaCl2, or ATP or both resulted in an equal and opposite enhancement of the PLC effect. Phospholipases B and D had no effect on [3H]nitrendipine binding. These data support: (1) Direct effect of PLA2 on dihydropyridine binding. (2) Indirect regulation of dihydropyridine binding by Phospholipase C through a GTP and ATP-sensitive mechanism.
AB - We compared the effects of Phospholipases A2, C, B and D on [3H]nitrendipine binding to hamster cardiac membranes, in the absence and presence of ATP or GTP. Phospholipase A2, competitively inhibited [3H]nitrendipine binding to hamster cardiac membranes unchanged by ATP or GTP (Ki = 5 ng/ml); as evidenced by complete and reversible displacement of [3H]nitrendipine binding and increase in KD on Scatchard analyses. Phospholipase C also completely inhibited [3H]nitrendipine binding to hamster cardiac membranes (Ki = 5 ug/ml) with a decrease in Bmax and no change in KD on Scatchard analyses. The addition of GTP alone inhibited the PLC effect in EGTA-treated membranes. The addition of GTP with either CaCl2, or ATP or both resulted in an equal and opposite enhancement of the PLC effect. Phospholipases B and D had no effect on [3H]nitrendipine binding. These data support: (1) Direct effect of PLA2 on dihydropyridine binding. (2) Indirect regulation of dihydropyridine binding by Phospholipase C through a GTP and ATP-sensitive mechanism.
UR - http://www.scopus.com/inward/record.url?scp=0026611414&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026611414&partnerID=8YFLogxK
U2 - 10.1016/0024-3205(92)90098-A
DO - 10.1016/0024-3205(92)90098-A
M3 - Article
C2 - 1313132
AN - SCOPUS:0026611414
VL - 50
SP - 1031
EP - 1041
JO - Life Sciences
JF - Life Sciences
SN - 0024-3205
IS - 14
ER -