Antihypertensive and bilateral renal responses to diuretics in 2-kidney, 1-clip Goldblatt hypertensive rats.
Experiments were conducted to assess the effect of furosemide or amiloride alone and a combination of both agents on each kidney in anesthetized 2-kidney, 1 clip Goldblatt hypertensive rats (n = 25). Intravenous infusion of furosemide alone (1.02 mg/kg.hr) significantly reduced the blood pressure by 14 +/- 5 mmHg. There were 6- to 10-fold increases in water, absolute sodium and fractional sodium excretions and a 2-fold increase in potassium excretion in the nonclipped kidney. A smaller but significant increase in the excretory function was also observed in the clipped kidney. There was no significant change in GFR of both kidneys. Indomethacin pretreatment (2 mg/kg) failed to significantly alter the vasodepressor and renal responses to furosemide in both hypertensive and normal rats. Removal of the renal artery clip from the hypertensive rats reduced the blood pressure by 12 +/- 3 mmHg and enhanced the function of the ipsilateral, unclipped kidney. Subsequent administration of furosemide further increased the excretory response. Administration of amiloride alone (2.4 mg/kg.hr) or with furosemide into hypertensive rats reduced the arterial pressure and increased excretion rates of urine flow and urinary sodium. Potassium excretion rate decreased bilaterally in amiloride treated rats but did not alter significantly in rats which received a combination of amiloride and furosemide. These results indicate that diuretics ameliorate the excretory function of both the stenotic kidney and the nonstenotic kidney and that the improvement of the kidney function is independent of prostaglandin. Furthermore, removal of the stenosis accentuates the beneficial effect of diuretics on the kidney.
Huang
W C
WC
Department of Physiology and Biophysics, National Defense Medical Center, Taipei, R.O.C.
Wu
J N
JN
Han
Y F
YF
Tsai
L M
LM
D000584:Amiloride / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005665:Furosemide / Q000494:pharmacology* / Q000627:therapeutic use; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006978:Hypertension, Renovascular / Q000188:drug therapy / Q000503:physiopathology*; D007213:Indomethacin / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D000584:Amiloride; D005665:Furosemide; D007213:Indomethacin