Tubular site(s) of action of atrial natriuretic peptide in the rat.
With micropuncture techniques, the present study examined the delivery of chloride to the superficial late distal tubule and the base and tip of the papillary collecting duct in rats treated with either Wy 47663, a synthetic analogue of atrial natriuretic peptide (ANP), or vehicle alone. Whole kidney glomerular filtration rate (GFR) and single-nephron glomerular filtration rate were not significantly different between the two groups. Late distal tubule chloride delivery was also not different between ANP- (5.71 +/- 1.15%) and vehicle- (6.28 +/- 1.12%) treated animals. However, fractional delivery to the base of the papillary collecting duct was significantly greater in the ANP-treated rats (14.37 +/- 1.98%) compared with vehicle-treated rats (7.32 +/- 1.47%). Tip papillary collecting duct delivery was also significantly greater in the ANP-treated rats (1.97 +/- 1.96 vs. 3.09 +/- 0.60%). In addition, the percent of chloride delivered that was reabsorbed along the papillary collecting duct was significantly less in the ANP-treated rats. In conclusion, ANP inhibits reabsorption in some tubular segments between the superficial late distal tubule and papillary collecting duct base as well as in the accessible portion of the papillary collecting duct.
Fried
T A
TA
Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7882.
Osgood
R W
RW
Stein
J H
JH
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001794:Blood Pressure; D002712:Chlorides / Q000378:metabolism; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007444:Inulin / Q000493:pharmacokinetics; D007684:Kidney Tubules / Q000187:drug effects / Q000502:physiology*; D007686:Kidney Tubules, Distal / Q000502:physiology; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012079:Renal Circulation
D002712:Chlorides; D010446:Peptide Fragments; C042703:anaritide; D009320:Atrial Natriuretic Factor; D007444:Inulin