Effect of cAMP analogue infusion on phosphate reabsorption in phosphate-deprived rats
Berndt, T.J.; Onsgard, M.J.; Knox, F.G.
American Journal of Physiology 255(1 Pt 2): F96-F99
1988
ISSN/ISBN: 0002-9513 PMID: 2839992 Document Number: 307527
The effects of 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (cAMP analogue) and parathyrin (PTH) infusion on segmental phosphate reabsorption in phosphate-deprived rats were studied. Micropunctures of the late proximal and the early distal tubules were made in acutely thyroparathyroidectomized (TPTX) rats given a normal (NPD) or low-phosphate diet (LPD), and the phosphaturic response to infusion of PTH and cAMP analogue was evaluated. In NPD rats, PTH and the cAMP analogues markedly increased urinary phosphate excretion, due to inhibition of phosphate reabsorption along the proximal convoluted tubule and pars recta. In phosphate-deprived rats, PTH or cAMP analogue did not increase urinary phosphate excretion. PTH and cAMP analogue inhibited phosphate reabsorption along the proximal convoluted tubule but not in the pars recta in phosphate-deprived rats.