Phosphorylation in coronary artery cold-induced contraction in the newborn lamb

Cryobiology
N S DahdahL C Wagerle

Abstract

Myocardial dysfunction after hypothermic protection has been linked to various mechanisms. Coronary vasospasm in particular may be responsible for ischemic injury during reperfusion. Herein we hypothesized that coronary arteries (CA) sustain a cold-induced contraction during hypothermia mediated by a protein tyrosine kinase (PTK)-/protein tyrosine phosphatase (PTP)-dependent pathway. Isolated newborn lamb CA rings were studied in a tissue bath for isometric contraction during 2-h profound (17 degrees C) or ultra-profound (7 degrees C) hypothermia. In parallel, protein tyrosine phosphorylation was evaluated by use of the Western blot technique. Na-orthovanadate (SOV) and genestein (GEN) were used separately and in combination to evaluate the effect of PTK/PTP activation on CA contraction and tyrosine phosphorylation during cooling (17 or 7 degrees C) vs 37 degrees C. Cooling from 37 to 7 degrees C induced transient contraction at approximately 17 degrees C (29% KCl response), which was more prominent during rewarming to 37 degrees C (36% KCl). Cooling to 17 degrees C resulted in sustained contraction (7-10% KCl), which was reversible upon rewarming. Cold-induced contraction was significantly enhanced by SOV (7- to 10-fold at 17 ...Continue Reading

Citations

Sep 24, 2002·American Journal of Transplantation : Official Journal of the American Society of Transplantation and the American Society of Transplant Surgeons·Jonathan F McAnultyChristopher J Murphy
Jan 17, 2009·Resuscitation·T SpangenbergK-H Kuck
Jan 13, 2009·Free Radical Biology & Medicine·Michael A J Zieger, Mahesh P Gupta

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