The effect of dopamine on adenylate cyclase and Na+,K(+)-ATPase activity in the developing rat renal cortical and medullary tubule cells.
Dopamine has an age-dependent natriuretic and diuretic effect. We have investigated the ontogeny of the dopamine response on adenylate cyclase activity and Na+,K(+)-ATPase activity in two different cell populations in the infant (10-d-old) and the adult (40-d-old) rat kidney. Basal- and forskolin-stimulated adenylate cyclase activity in tubular suspensions of renal cortex was 5.4-fold (p < 0.05) higher in the 10-d-old rats than in the 40-d-old rats but unchanged between the ages in a suspension of medullary tubules. The dopamine-1-specific agonist fenoldopam did not stimulate adenylate cyclase activity in the cortical cells from 10-d-old rats but did stimulate activity 51 +/- 16% (p < 0.05) in the 40-d-old rats. In the medullary suspension, fenoldopam stimulated adenylate cyclase activity by 43.5 +/- 5% (p < 0.001) in the 10-d-old rats and by 32.0 +/- 7% (p < 0.01) in the 40-d-old rats. In the isolated proximal convoluted tubule, dopamine inhibited Na+,K(+)-ATPase activity in both the 10-d-old (34 +/- 3%, p < 0.001) and 40-d-old rats (44 +/- 7%, p < 0.001). In contrast, in the medullary thick ascending limb of Henle, inhibition of Na+,K(+)-ATPase activity by fenoldopam was more pronounced in the 10-d-old (56 +/- 6%, p < 0.001) than in the 40-d-old rat (33 +/- 6%, p < 0.001). In summary, the renal tubular effects of dopamine on adenylate cyclase and Na+,K(+)-ATPase activity change during postnatal development in a cell-specific manner.
Fryckstedt
J
J
Department of Pediatrics, St. Gören's Children's Hospital, Karolinska Institutet, Stockholm, Sweden.
Svensson
L B
LB
Lindén
M
M
Aperia
A
A
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000031:analogs & derivatives / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000367:Age Factors; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004298:Dopamine / Q000494:pharmacology*; D018818:Fenoldopam; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D008138:Loop of Henle / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D011954:Receptors, Dopamine; D005576:Colforsin; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D000254:Sodium-Potassium-Exchanging ATPase; D018818:Fenoldopam; D004298:Dopamine