Effects of parathyroid hormone on urinary excretion of N-acetyl-β-D-glucosaminidase in idiopathic hypoparathyroidism and pseudohypoparathyroidism

Summary N-acetyl-β-D-glucosaminidase(NAG) is a lysosomal enzyme predominantly located in renal proximal tubules. In idiopathic hypoparathyroidism(IHP), 100 Units of human PTH(1–34) increased urinary excretion of NAG from 0.029±0.027 to 0.173±0.035 U/1GF (p<0.05) in two patients before treatment and from 0.025±0.004 to 0.189±0.092U/1GF (p<0.02) in four patients during treatment with active vitamin D₃ (1,25(OH)₂D₃ or 1αOHD₃). In pseudohypoparathyroidism(PHP), PTH did not significantly increase the urinary excretion of NAG in one patient with before treatment (0.048 to 0.025 U/1GF) and four patients during treatment with active vitamin D₃ (0.018±0.008 to 0.036±0.015 U/1GF). Increase in urinary excretion of NAG after injection of PTH may be a new indicator of renal effect of PTH.