VERAPAMIL PRETREATMENT PRESERVES MITOCHONDRIAL-FUNCTION AND TISSUE MAGNESIUM IN THE ISCHEMIC KIDNEY

  • 1 January 1984
    • journal article
    • research article
    • Vol. 13  (1) , 27-37
Abstract
These studies were designed to test the efficacy and possible mechanisms of the prevention of mitochondrial functional deterioration in renal ischemia by the slow channel Ca blocker verapamil. Renal ischemia was induced in guinea pigs by a unilateral ligation of the renal artery for 30 or 60 min. In the pretreated animals verapamil was given twice a day over a 5-d [day] period prior to the induction of ischemia. Sham-operated animals were used as normal controls. After 30 and 60 min, the kidneys were removed and used for mitochondrial isolation and analyses, total tissue Ca2+ and Mg2+ determinations or for EM. Verapamil pretreatment completely blocked the decrease of mitochondrial Ca2+ uptake rate induced by 30 or 60 min of ischemia. The pretreatment delayed by 30 min the ischemic decrease of state 3 respiratory activity. Total tissue Ca2+ concentration was not altered by ischemia or verapamil pretreatment. Total tissue Mg2+ concentration, however, was significantly reduced in the ischemic kidney at 60 min. This reduction was prevented completely by verapamil pretreatment. The mitochondrial functional deterioration induced by 30 min of ischemia evidently is a primary cellular insult secondarily leading to loss of tissue Mg2+. The point of irreversibility in the ischemic cell injury might be initiated by lowered tissue Mg2+/Ca2+ ratios.