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Internal and External Effects of Dihydropyridines in the Calcium Channel of Skeletal Muscle

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Journal J Gen Physiol
Specialty Physiology
Date 1990 Jan 1
PMID 2153750
Citations 8
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Abstract

The agonist effect of the dihydropyridine (DHP) (-)Bay K 8644 and the inhibitory effects of nine antagonist DHPs were studied at a constant membrane potential of 0 mV in Ca channels of skeletal muscle transverse tubules incorporated into planar lipid bilayers. Four phenylalkylamines (verapamil, D600, D575, and D890) and d-cis-diltiazem were also tested. In Ca channels activated by 1 microM Bay K 8644, the antagonists nifedipine, nitrendipine, PN200-110, nimodipine, and pure enantiomer antagonists (+)nimodipine, (-)nimodipine, (+)Bay K 8644, inhibited activity in the concentration range of 10 nM to 10 microM. Effective doses (ED50) were 2 to 10 times higher when HDPs were added to the internal side than when added to the external side. This sidedness arises from different structure-activity relationships for DHPs on both sides of the Ca channel since the ranking potency of DHPs is PN200-110 greater than (-)nimodipine greater than nifedipine approximately S207-180 on the external side while PN200-110 greater than S207-180 greater than nifedipine approximately (-)nimodipine on the internal side. A comparison of ED50's for inhibition of single channels by DHPs added to the external side and ED50's for displacement of [3H]PN200-110 bound to the DHP receptor, revealed a good quantitative agreement. However, internal ED50's of channels were consistently higher than radioligand binding affinities by up to two orders of magnitude. Evidently, Ca channels of skeletal muscle are functionally coupled to two DHP receptor sites on opposite sides of the membrane.

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References
1.
Cheng Y, Prusoff W . Relationship between the inhibition constant (K1) and the concentration of inhibitor which causes 50 per cent inhibition (I50) of an enzymatic reaction. Biochem Pharmacol. 1973; 22(23):3099-108. DOI: 10.1016/0006-2952(73)90196-2. View

2.
Lacerda A, Brown A . Nonmodal gating of cardiac calcium channels as revealed by dihydropyridines. J Gen Physiol. 1989; 93(6):1243-73. PMC: 2216246. DOI: 10.1085/jgp.93.6.1243. View

3.
Hescheler J, Pelzer D, Trube G, TRAUTWEIN W . Does the organic calcium channel blocker D600 act from inside or outside on the cardiac cell membrane?. Pflugers Arch. 1982; 393(4):287-91. DOI: 10.1007/BF00581411. View

4.
Bolger G, Gengo P, Klockowski R, Luchowski E, Siegel H, Janis R . Characterization of binding of the Ca++ channel antagonist, [3H]nitrendipine, to guinea-pig ileal smooth muscle. J Pharmacol Exp Ther. 1983; 225(2):291-309. View

5.
Lee K, Tsien R . Mechanism of calcium channel blockade by verapamil, D600, diltiazem and nitrendipine in single dialysed heart cells. Nature. 1983; 302(5911):790-4. DOI: 10.1038/302790a0. View