Impaired renal response to parathyroid hormone in potassium depletion
Beck, N.; Davis, B.B.
American Journal of Physiology 228(1): 179-183
1975
ISSN/ISBN: 0002-9513 PMID: 167590 Document Number: 87097
In K depletion, a possible alteration of the proximal tubular response to parathyroid hormone (PTH) was evaluated in rat kidney. There were impairments of both phosphaturic and urine cyclic AMP responses to PTH. The site of impairment was further examined by study of the PTH-dependent cyclic AMP system in renal cortex. There was a smaller increase of cyclic AMP concentration by PTH in K-depleted slices, indicating the fall of urine cyclic AMP was due to the specific impairment of PTH-dependent cyclic AMP in the kidney. The activation of adenylate cyclase by PTH was impaired, but phosphodiesterase activity was not affected by K depletion, indicating that impairment of cyclic AMP generation was due to the inhibition of adenylate cyclase. The phosphaturic response to dibutyryl cyclic AMP infusion was also significantly less in the rats depleted in K, indicating that the step subsequent to the cyclic AMP generation is also impaired.