PT  - JOURNAL ARTICLE
AU  - Kohmoto, O
AU  - Barry, W H
TI  - Mechanism of protective effects of Ca++ channel blockers on energy deprivation contracture in cultured ventricular myocytes.
DP  - 1989 Feb 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 871--878
VI  - 248
IP  - 2
4099  - http://jpet.aspetjournals.org/content/248/2/871.short
4100  - http://jpet.aspetjournals.org/content/248/2/871.full
SO  - J Pharmacol Exp Ther1989 Feb 01; 248
AB  - To examine mechanisms of the protective effects of Ca++ channel blockers on energy deprivation contracture, we measured cystolic calcium ion concentration ([Ca++]i) (Indo-1 fluorescence), development of contracture (video motion detector) and ATP contents during exposure of cultured chick embryo ventricular cells to 1 mM cyanide (CN) and 20 mM 2-deoxyglucose (2-DG). The time periods required for [Ca++]i to reach 50% of [Ca++]i transient ([Ca++]i-50) and contracture were determined after exposure to 1) CN + 2-DG alone, 2) CN + 2-DG simultaneous with 1 microM verapamil (V-sim) and 3) verapamil followed by CN + 2-DG (V-pre). Time periods required to reach [Ca++]i-50 under these conditions were 4.2 +/- 0.4 min (CN + 2-DG alone), 3.8 +/- 0.4 min (NS vs. CN + 2-DG alone) (V-sim) and 6.4 +/- 1.1 min (P less than .05 vs. CN + 2-DG alone) (V-pre), respectively. Time periods required for contracture development were 4.4 +/- 0.3 min (CN + 2-DG alone), 4.4 +/- 0.6 min (NS vs. CN + 2-DG alone) (V-sim) and 9.3 +/- 1.2 min (P less than .05 vs. CN + 2-DG alone) (V-pre). Three minutes after metabolic inhibition, ATP contents declined from 32.3 +/- 0.7 nmol/mg of protein to 4.2 +/- 1.0 in CN + 2-DG alone, to 4.5 +/- 0.9 (NS vs. CN + 2-DG alone) with V-sim and to 8.3 +/- 2.2 (P less than .05 vs. CN + 2-DG alone) with V-pre.(ABSTRACT TRUNCATED AT 250 WORDS)