Open AccessConcerted regulation of renal plasma flow and glomerular filtration rate by renal dopamine and NOS I in rats on high salt intake
Author(s) -
Ibarra Mariano E.,
Albertoni Borghese Maria F.,
Majowicz Mónica P.,
Ortiz María C.,
Loidl Fabián,
ReyFunes Manuel,
Di Ciano Luis A.,
Ibarra Fernando R.
Publication year - 2017
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.13202
Subject(s) - endocrinology , medicine , natriuresis , macula densa , chemistry , renal function , diuresis , tubuloglomerular feedback , renal blood flow , excretion , nicotinamide adenine dinucleotide phosphate , enzyme , biochemistry , renin–angiotensin system , blood pressure , oxidase test
Under high sodium intake renal dopamine ( DA ) increases while NOS I expression in macula densa cells ( MD ) decreases. To explore whether renal DA and NOS I, linked to natriuresis and to the stability of the tubuloglomerular feedback, respectively, act in concert to regulate renal plasma flow ( RPF ) and glomerular filtration rate ( GFR ). Male Wistar rats were studied under a normal sodium intake ( NS , NaCl 0.24%) or a high sodium intake ( HS , NaCl 1% in drinking water) during the 5 days of the study. For the last two days, the specific D 1 ‐like receptor antagonist SCH 23390 (1 mg kg bwt −1 day −1 , sc) or a vehicle was administered. HS intake increased natriuresis, diuresis, and urinary DA while it decreased cortical NOS I expression ( P < 0.05 vs. NS ), Nicotinamide adenine dinucleotide phosphate diaphorase ( NADPH ‐d) activity in MD ( P < 0.001 vs. NS ) and cortical nitrates+nitrites ( NO x) production ( NS 2.04 ± 0.22 vs. HS 1.28 ± 0.10 nmol mg protein −1 , P < 0.01). Treatment with SCH 23390 to rats on HS sharply decreased hydroelectrolyte excretion ( P < 0.001 vs. HS ) while NOS I expression, NADPH ‐d activity and NO x production increased ( P < 0.05 vs. HS for NOS I and P < 0.001 vs. HS for NADPH ‐d and NO x). SCH 23390 increased RPF and GFR in HS rats ( P < 0.01 HS + SCH vs. HS ). It did not cause variations in NS rats. Results indicate that when NS intake is shifted to a prolonged high sodium intake, renal DA through the D 1 R, and NOS I in MD cells act in concert to regulate RPF and GFR to stabilize the delivery of NaCl to the distal nephron.