Estrogens play a major role in mineral homeostasis, however it remains unclear whether they exert regulatory action upon reabsorption of phosphate (Pi) in proximal tubules of the kidney. We investigated the effect of β-estradiol (E2) injected to thyroparathyrodectomized and ovarectomized rats upon Na+-cotransport of Pi and other solutes across renal brush border membrane (BBM). In BBM from kidneys of E2-treated rats the capacity for Na+-Pi cotransport was considerably suppressed (Δ% - 42; P < 0.01) whereas Na+-cotransports of L-proline D-glucose and SO4 across the same BBM did not differ from controls. We surmise that E2 inhibits selectively Na+-Pi cotransport by direct interaction with E2 receptors in proximal tubular cells. These results indicate the existence of the inhibitory effect of estrogens upon renal proximal tubular Na+-Pi cotransport and, by extention, proximal Pi reabsorption. We suggest that this modulatory action of E2 plays a role in pathophysiology of mineral metabolism due to estrogen deficiency and should be considered when estrogens are used for pharmacotherapy of postmenopausal osteoporosis and some types of cancer.
|Original language||English (US)|
|Number of pages||4|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Apr 16 1996|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology