title: Uninephrectomy prevents the ischemia-induced increase in renin activity.
abstract: Contralateral uninephrectomy attenuates unilateral ischemic injury. The present work was performed to elucidate whether the beneficial effect of uninephrectomy was associated with the modification of ischemia-induced changes in plasma or renal renin activity. A 60-min left renal artery occlusion was conducted in right nephrectomized (Nx) and sham-nephrectomized (Sham-Nx) rats. The decline in inulin clearance 48 h after ischemia was significantly less in Nx rats than in Sham-Nx animals (0.50 +/- 0.10 vs. 0.052 +/- 0.029 ml/min/kidney, p < 0.05). Following ischemia, plasma renin activity (PRA) significantly increased in Sham-Nx (from 5.4 +/- 0.9 to 15.5 +/- 1.4 ng AI/ml/min, p < 0.01) but not in Nx (from 3.5 +/- 0.5 to 5.0 +/- 1.0 ng AI/ml/ min) animals. PRA and renal cortical renin content (2,200 +/- 225 vs. 1,257 +/- 187 ng AI/h/mg protein, p < 0.05) were significantly less in Nx rats than in Sham-Nx animals 48 h after renal ischemia. The decrease in body weight was greater in Nx rats than in Sham-Nx animals. Plasma atrial natriuretic peptide (ANP) (195 +/- 30 vs. 302 +/- 40 pg/ml, p < 0.05) and renal dopamine (DA) content (3.2 +/- 0.5 vs. 13.7 +/- 1.3 ng/g tissue, p < 0.01) were rather lower in the Nx group when compared with the Sham-Nx group. No significant difference was found in the intrarenal content of norepinephrine (NE) between two ischemic groups. These findings suggested that uninephrectomy prevents the ischemia-induced increase in renin activity. The prevention of the increase in renin activity in Nx rats is not be mediated through the modulation of ischemia-induced changes in sodium balance, plasma ANP level and/or intrarenal contents of NE and DA.
authors.affiliation: First Department of Medicine, Hamamatsu University School of Medicine, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kato
authors.forename: A
authors.initials: A
authors.lastname: Hishida
authors.forename: I
authors.initials: I
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Komatsu
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood; D001835:Body Weight; D002250:Carbon Radioisotopes; D004298:Dopamine / Q000378:metabolism; D007444:Inulin / Q000493:pharmacokinetics; D007511:Ischemia / Q000097:blood / Q000517:prevention & control*; D007668:Kidney / Q000098:blood supply* / Q000378:metabolism; D008297:Male; D009392:Nephrectomy; D009638:Norepinephrine / Q000097:blood; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D012078:Renal Artery Obstruction / Q000150:complications; D012083:Renin / Q000097:blood*; D015427:Reperfusion Injury / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D012964:Sodium / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D009320:Atrial Natriuretic Factor; D007444:Inulin; D012964:Sodium; D012083:Renin; D004298:Dopamine; D009638:Norepinephrine