Testosterone enhances calcium reabsorption by the kidney.

The kidney is a target tissue for androgens, but the role of these hormones in the regulation of calcium (Ca2+) reabsorption remains unclear. The present study examines the effects of testosterone on Ca2+ transport by the luminal membranes of proximal and distal nephrons of the rabbit kidney. Tubule suspensions were pre-incubated in the presence or absence of the hormone, and 45C2+ uptake by the luminal membranes was measured using the rapid filtration technique.

Aldosterone enhances renal calcium reabsorption by two types of channels.

Background: Aldosterone has been known for many years to increase sodium (Na(+)) reabsorption by the distal nephron. The present in vitro experiments investigated the effect of the hormone on calcium (Ca(2+)) transport by the luminal membrane of the rabbit nephron, independent of any systemic influence.

Methods: Proximal and distal tubules were incubated with either aldosterone or the carrier.

Renal action of progesterone: effect on calcium reabsorption.

Recently, the kidney has been reported to be the site of receptors for progesterone. Although the exact segment of the nephron has not been precisely determined, the cortical collecting tubule was suspected, since the hormone displaces bound 3H aldosterone. The aim of the present study was to investigate the effect of progesterone on calcium (Ca(2+)) transport by the renal luminal membranes and to determine the site and mechanisms of action.