Inhibition by lithium and rubidium of gentamicin-induced release of N-acetyl-beta-D-glucosaminidase from perfused rat kidney.
N-acetyl-beta-D-glucosaminidase (NAG) is one of the sensitive hydrolytic lysosomal enzymes which is released after renal tubular damages. We studied gentamicin-induced nephrotoxicity by determining the NAG release in perfused rat kidney. 100 micrograms/ml of gentamicin caused a time-dependent increase in enzymuria, peaking at 90 min. At this time the released NAG is about sixfold more than the control. The effect of concurrent perfusion with 100 micrograms/ml gentamicin and with 0.5 mmol/l lithium chloride or 0.5 mmol/l rubidium chloride in the perfusion fluid was also studied by measuring NAG activity in the perfusate. Both cations decrease the gentamicin-induced NAG release. However, the inhibitory effect of lithium chloride may be due to interference of this ion with the polyphosphoinositide cycle in renal tubular lysosomal membranes. There is no obvious evidence for an inhibitory effect of rubidium chloride.
Dehpour
A R
AR
Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Iran.
Ghafourifar
P
P
Ahangari
N
N
D000118:Acetylglucosaminidase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D002712:Chlorides / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005839:Gentamicins / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology; D007684:Kidney Tubules / Q000187:drug effects / Q000473:pathology; D018021:Lithium Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010477:Perfusion; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012413:Rubidium / Q000008:administration & dosage / Q000494:pharmacology*
D002712:Chlorides; D004791:Enzyme Inhibitors; D005839:Gentamicins; D018129:Phosphatidylinositol Phosphates; D000118:Acetylglucosaminidase; D018021:Lithium Chloride; D012413:Rubidium; C032710:rubidium chloride