Parathyroid Hormone and Adenosine-3′,5′-Monophosphate Acutely Increase Phospholipids of the Phosphatidate-Polyphosphoinositide Pathway in Rabbit Kidney Cortex Tubulesin Vitroby a Cycloheximide-Sensitive Process*

Abstract

Parathyroid hormone (PTH) rapidly increased the concentrations of phosphatidic acid, phosphatidylinositol, diphosphoinositide, and triphosphoinositide during incubations of rabbit kidney cortical tubules in vitro. These effects were preceded by increases in cAMP, which also induced virtually identical increases in these phospholipids. Pretreating the tubules with cycloheximide inhibited these phospholipid effects of PTH and cAMP. These findings are similar to those reported for ACTH and cAMP in the adrenal cortex. Hormones that utilize cAMP as their ”second messenger“ may influence membrane structure and function via stimulation of the phosphatidate-polyphosphoinositide pathway.