Intrarenal beta-adrenergic stimulation enhances excretion of urinary lysosomal enzyme in anesthetized dogs

The effects of intrarenal administration of isoproterenol on excretion of urinary enzymes were examined in dogs. Urinary N-acetyl-beta-D-glucosaminidase (NAG) and glutamyl transpeptidase (gamma-GTP) originated from lysosomes and the brush border membrane of the kidney, respectively. NAG excretion was elevated for 10 min by isoproterenol (0.2 microgram/kg/min) without a drastic change in glomerular filtration rate and renal blood flow. This elevation was inhibited by pretreatment with d,l-propranolol (0.6 mg/kg bolus injection 0.3 mg/kg/30 min) but less so by d-propranolol. Urinary gamma-GTP excretion was little affected by isoproterenol. In light of these findings, the possibility that beta-receptors may be involved in the excretion of NAG has to be considered.