Salutary effects of cysteine on cardiogenic shock in cats
Galvin, M.J.; Lefer, A.M.
American Journal of Physiology 235(6): H657-H663
1978
ISSN/ISBN: 0002-9513 PMID: 736153 Document Number: 127951
The sulfhydryl-containing amino acid cysteine was injected at concentrations of 100 mg/kg i.v., followed by a 5 h infusion of 10 mg/(kg .cntdot. h), in cats subjected to cardiogenic shock induced by ligation of the left anterior descending and circumflex branches of the left coronary artery or subjected to a sham operation. These groups of cats were compared with cats subjected to cardiogenic shock and infused with 0.9% NaCl as a vehicle control. Cats subjected to cardiogenic shock developed large S-T segment elevations and high circulating plasma activity of creatinine phosphokinase (CPK). Cysteine did not alter the S-T segment or plasma CPK changes, but maintained arterial blood pressure in cats subjected to cardiogenic shock. This improved hemodynamic state was not due to changes in heart rate or to central venous pressure. Cysteine also prevented the plasma accumulation of the lysosomal hydrolase, cathepsin D and the toxic factor, myocardial depressant factor (MDF), and maintained hepatic and cardiac nonprotein sulfhydryl concentrations in cardiogenic shock. Cysteine appears to exert beneficial effects in shock primarily by modulation of cellular metabolism and stabilization of lysosomal membranes rather than by direct hemodynamic actions.