Bicarbonate transport along the loop of Henle effects of adrenal steroids
Unwin, R.; Capasso, G.; Giebisch, G.
American Journal of Physiology 268(2 Pt 2): F234-F239
1995
ISSN/ISBN: 0002-9513 PMID: 7864161 Document Number: 453057
The role of adrenal steroids in the regulation of bicarbonate absorption in the loop of Henle was studied by in vivo microperfusion. Bicarbonate transport (J-HCO-3) was measured by microcalorimetry and fluid reabsorption by (14C)inulin, 7-10 days after surgery, in 1) sham-operated control rats, 2) adrenalectomized (Adx) rats, 3) Adx rats receiving dexamethasone (1.2 mu-g . 100 g body wt-1 cntdot 24 h-1) and a low dose of aldosterone (0.5 mu-g cntdot 100 g body wt-1 cntdot 24 h-1), 4) Adx rats receiving dexamethasone, 5) Adx rats receiving a low dose of aldosterone, and 6) Adx rats receiving a high dose of aldosterone (1.0 mu-g cntdot 100 g body wt-1 cntdot 24 h-1). J-HCO-3 along the loop of Henle was decreased by 40% in Adx rats. J-HCO-3 was increased by dexamethasone alone and by dexamethasone plus a low dose of aldosterone to rates observed in fully supplemented Adx rats. Aldosterone given alone at a low physiological dose had no effect, but, when administered at a high dose, returned J-HCO-3 to normal.