Renal medullary captopril delivery lowers blood pressure in spontaneously hypertensive rats. Hypertension 1994 Mar;23(3):337-45
Date
03/01/1994Pubmed ID
8125560DOI
10.1161/01.hyp.23.3.337Scopus ID
2-s2.0-0028294355 (requires institutional sign-in at Scopus site) 81 CitationsAbstract
We examined the contribution of renal medullary function to the maintenance of hypertension in spontaneously hypertensive rats by infusing captopril chronically into the renal medullary interstitial space of uninephrectomized rats. Changes in cortical and medullary blood flow were determined using a newly developed optical fiber implantation technique for laser-Doppler flowmetry. Renal medullary interstitial infusion of captopril (5 mg/kg per day) selectively increased medullary blood flow by 40% without altering renal cortical blood flow throughout the 5 days of captopril delivery. In association with the selective increase of medullary perfusion, a significant natriuresis was observed on the second day of the drug infusion, and urine osmolality was significantly reduced during the first 3 days of captopril infusion. Mean arterial pressure was significantly decreased by 20 mm Hg during 5 days of captopril infusion, and the chronic renal function curve was shifted to a lower level of arterial pressure compared with the control values when 0.9% sodium chloride saline vehicle was infused. Intravenously infused captopril at 5 mg/kg per day did not alter mean arterial pressure, excluding the possibility that the hypotensive effect of medullary captopril infusion was due to recirculation. In summary, chronic reduction of the elevated renal medullary vascular tone by medullary interstitial infusion of captopril reset the steady-state renal function curve and lowered arterial pressure in spontaneously hypertensive rats.
Author List
Lu S, Mattson DL, Cowley AW JrAuthor
Allen W. Cowley Jr PhD Professor in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBlood Pressure
Captopril
Dose-Response Relationship, Drug
Hypertension
Infusions, Intravenous
Kidney
Kidney Medulla
Male
Rats
Rats, Inbred SHR
Renal Circulation
Renin
Sodium
