Parathyroid hormone stimulation of renal phosphoinositide metabolism is a cyclic nucleotide-independent effect

Victor Meltzer, Steven Weinreb, Ezequiel Bellorin-Font, Keith A. Hruska

Research output: Contribution to journalArticlepeer-review

41 Scopus citations

Abstract

The effects of parathyroid hormone (PTH) and cyclic nucleotides on renal phosphoinositide metabolism were studied using cortical tubules isolated from dog kidneys. PTH stimulated the initial rates of 32Pi incorporation into phosphatidylinositol 4'5'-diphosphate, phosphatidylinositol 4'-monophosphate, phosphatidylinositol and phosphatidic acid. PTH also caused a 45-55% increase in the actual tissue levels of these phospholipids by 5 min of incubation. By 30 min of incubation, the levels of 32i incorporated were similar in PTH and control flasks, but the actual levels of the phosphoinositides remained elevated, indicating stimulation of their turnover. Additional evidence of increased turnover of phosphatidylinositol was obtained from tubules pre-incubated with myo-[2-3H] inositol. PTH stimulated a rapid short-lived decrement in [3H]phosphati-dylinositol while total phosphatidylinositol levels increased, indicating increased turnover rates of phosphati-dylinositol. In tubules pre-incubated with [14C]arachidonic acid, PTH increased the initial rates of [14C]di-acylglycerol production and decreased release of [14C]arachidonic acid, indicating utilization of diacylglycerol produced during turnover for resynthesis of phosphatidic acid and phosphoinositides. Cyclic nucleotides and phosphodiesterase inhibition failed to reproduce the effect of PTH on phosphoinositide metabolism. These studies indicate that PTH stimulates renal phosphoinositide metabolism through a mechanism independent of cAMP which results in a net synthesis of the phosphoinositides.

Original languageEnglish
Pages (from-to)258-267
Number of pages10
JournalBiochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism
Volume712
Issue number2
DOIs
StatePublished - Aug 18 1982

Keywords

  • (Dog kidney)
  • Parathyroid hormone
  • Phosphatidic acid
  • Phosphatidylinosilol phosphate
  • Phosphatidylinositol
  • Phospholipid
  • cyclic A MP

Fingerprint

Dive into the research topics of 'Parathyroid hormone stimulation of renal phosphoinositide metabolism is a cyclic nucleotide-independent effect'. Together they form a unique fingerprint.

Cite this