HUMAN PARATHYROID-HORMONE RELATED PROTEIN FRAGMENT-(1-34) HAD GLUCOSE-6-PHOSPHATE-DEHYDROGENASE ACTIVITY ON DISTAL CONVOLUTED TUBULES IN CYTOCHEMICAL BIOASSAY

In the present study, the action of parathyroid hormone related protein (PTHrP) on glucose-6-phosphate dehydrogenase (G6PD) activity of the distal convoluted tubules was examined utilizing cytochemical bioassay (CBA). Recently full amino acid residues of human PTHrP (hPTHrP), one of the causative agents of HHM, was identified based on the cDNA clone using BEN cells. We synthesized hPTHrP-(1-34) and examined the effect of this protein on G6PD activities on the distal convoluted tubules, and compared its bioactivity to that of human parathyroid hormone (hPTH)-(1-84). hPTHrP-(1-34) stimulated G6PD activity in a log linear fashion with equivalent activity to that of hPTH-(1-84) on a molar basis. Conclusively, we found that PTHrP act on distal convoluted tubules similar to hPTH.