title: Captopril and tubuloglomerular feedback in remnant kidneys of prehypertensive rats.
abstract: The activity and characteristics of tubuloglomerular feedback (TGF) are altered subsequent to reductions in renal mass or blockade of the renin-angiotensin system. This study assessed the combined effects of renal ablation and captopril on TGF. Renal mass was reduced in male Sprague-Dawley rats by the surgical removal of 1 1/2 kidneys. At 2 and 8 wk postsurgery, TGF was studied by micropuncture before and after the administration of captopril (0.5 mg/kg i.v.) Before captopril, TGF in remnant kidneys (NX) was characterized by a higher tubular perfusion rate required for a 50% maximal response (TGF turning point) as compared with intact kidneys of controls (CNT) at both 2 (NX, 35 +/- 3; CNT, = 19 +/- 1 nL/min; P less than 0.05) and 8 wk (NX, 54 +/- 5; CNT, 20 +/- 1 nL/min; P less than 0.05). Captopril significantly increased the turning point in both intact and remnant kidneys at both 2 (NX, 43 +/- 2; CNT, 25 +/- 2 nL/min) and 8 wk (NX, 61 +/- 5; CNT, 28 +/- 2 nL/min) postsurgery. Captopril also significantly reduced the maximal TGF response in both intact and remnant kidneys at 2 (NX from 13 +/- 3 to 7 +/- 1 mm Hg; CNT from 10 +/- 1 to 5 +/- 1 mm Hg) and 8 wk (NX from 15 +/- 1 to 9 +/- 2 mm Hg; CNT from 13 +/- 1 to 7 +/- 1 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, Colorado State University, Fort Collins 80523.
authors.forename: W L
authors.initials: WL
authors.lastname: Wilke
authors.forename: A E
authors.initials: AE
authors.lastname: Persson
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight; D002216:Captopril / Q000494:pharmacology*; D005246:Feedback; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006973:Hypertension / Q000209:etiology*; D007668:Kidney / Q000473:pathology; D007678:Kidney Glomerulus / Q000187:drug effects*; D007684:Kidney Tubules / Q000187:drug effects*; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D009392:Nephrectomy / Q000379:methods; D009929:Organ Size; D051381:Rats
chemical_list: D002216:Captopril