RENAL MEDULLARY CAPTOPRIL DELIVERY LOWERS BLOOD-PRESSURE IN SPONTANEOUSLY HYPERTENSIVE RATS

被引:80
作者
LU, SH [1 ]
MATTSON, DL [1 ]
COWLEY, AW [1 ]
机构
[1] MED COLL WISCONSIN,DEPT PHYSIOL,MILWAUKEE,WI 53226
关键词
KIDNEY; KIDNEY MEDULLA; HEMODYNAMICS; CAPTOPRIL; RATS; INBRED SHR;
D O I
10.1161/01.HYP.23.3.337
中图分类号
R6 [外科学];
学科分类号
1002 ; 100210 ;
摘要
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 captropril 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.
引用
收藏
页码:337 / 345
页数:9
相关论文
共 29 条
  • [1] AONO J, 1988, ARCH INT PHARMACOD T, V292, P203
  • [2] RENAL-FUNCTION OF CONSCIOUS SPONTANEOUSLY HYPERTENSIVE RATS
    BEIERWALTES, WH
    ARENDSHORST, WJ
    [J]. CIRCULATION RESEARCH, 1978, 42 (05) : 721 - 726
  • [3] INVITRO PERFUSION OF JUXTAMEDULLARY NEPHRONS IN RATS
    CASELLAS, D
    NAVAR, LG
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1984, 246 (03): : F349 - F358
  • [4] ACUTE BLOOD-PRESSURE AND URINARY RESPONSES TO SINGLE DOSE COMBINATIONS OF CAPTOPRIL AND DIURETICS IN CONSCIOUS SPONTANEOUSLY HYPERTENSIVE RATS
    CHIU, PJS
    VEMULAPALLI, S
    BARNETT, A
    [J]. JOURNAL OF PHARMACY AND PHARMACOLOGY, 1985, 37 (02) : 105 - 109
  • [5] RENAL MEDULLARY CIRCULATION - HORMONAL-CONTROL
    CHOU, SY
    PORUSH, JG
    FAUBERT, PF
    [J]. KIDNEY INTERNATIONAL, 1990, 37 (01) : 1 - 13
  • [6] COWLEY AW, 1989, NEWS PHYSIOL SCI, V4, P219
  • [7] LONG-TERM CONTROL OF ARTERIAL BLOOD-PRESSURE
    COWLEY, AW
    [J]. PHYSIOLOGICAL REVIEWS, 1992, 72 (01) : 231 - 300
  • [8] NORMALIZATION OF PRESSURE NATRIURESIS BY NISOLDIPINE IN SPONTANEOUSLY HYPERTENSIVE RATS
    FENOY, FJ
    KAUKER, ML
    MILICIC, I
    ROMAN, RJ
    [J]. HYPERTENSION, 1992, 19 (01) : 49 - 55
  • [9] EFFECT OF VOLUME EXPANSION ON PAPILLARY BLOOD-FLOW AND SODIUM-EXCRETION
    FENOY, FJ
    ROMAN, RJ
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1991, 260 (06): : F813 - F822
  • [10] SUPERFICIAL AND JUXTAMEDULLARY NEPHRON FUNCTION DURING CONVERTING ENZYME-INHIBITION
    GORANSSON, A
    SJOQUIST, M
    ULFENDAHL, HR
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1986, 251 (01): : F25 - F33