The major tranquillizers

Rudenko, Gloria; Лепахин, В К

doi:10.1016/s0378-6080(79)80009-4

Cited by 2 publications

(1 citation statement)

References 22 publications

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“…Our in vitro observations may explain the in vivo effects of TFP, which has been shown to induce both bradycardia and hypotension when given to psychotic patients under controlled conditions (29). Similar to the present finding, the in vivo effects of TFP on cardiovascular function were reversible after removal of the drug.…”

Section: Discussionsupporting

confidence: 89%

Trifluoperazine Inhibits the Contraction of Cultured Rat Cardiac Cells and the Phosphorylation of Myosin Light Chain

Klein¹

1983

J. Clin. Invest.

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A B S T R A C T Cultured, spontaneously beating heart cells were used to study the role of calmodulin in regulating cardiac contraction. Trifluoperazine (TFP), an antipsychotic drug that binds to calmodulin, reversibly inhibited myocardial contraction. This effect occurred over a TFP concentration range of 5-100 MM with half maximal activity at -15 uM TFP. When the phosphoprotein profile of TFP-treated cells was compared with control cultures, there was a significant decrease in 32P content of the 20,000-D myosin light chain. As measured by two-dimensional gel electrophoresis, the fraction of phosphorylated myosin light chain decreased from 0.31±0.06 in control to 0.16±0.05 in TFP-treated cells (P < 0.05). This inhibition of protein phosphorylation was relatively selective, as two other phosphoproteins (-41,000 and 36,000 D) were unaffected, and a third protein (-28,000 D) showed an increase in 32P activity. In contrast, the cessation of spontaneous beating by 50 mM KC1 did not reproduce these changes. This inhibition of contraction mediated by TFP associated with alterations in the phosphorylation of certain cardiac phosphoproteins suggests a role for calmodulin and for the myosin light chain in the regulation of cardiac cell contraction.

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Section: Discussionsupporting

confidence: 89%