Khraibi A A, Liang M, Berndt T J
Department of Obstetrics and Gynecology, University of Illinois at Chicago, USA.
Am J Hypertens. 2001 Sep;14(9 Pt 1):893-6. doi: 10.1016/s0895-7061(01)02164-1.
The objective of this study was to compare renal interstitial hydrostatic pressure (RIHP) and sodium excretion in female and male Sprague-Dawley (SD) rats. The RIHP and pressure natriuresis responses were determined in female (n=13) and male (n=8) SD rats. Renal perfusion pressure (RPP) was controlled at two levels (100 and 120 mm Hg). Clearances were taken at each level and RIHP was measured with a chronically implanted polyethylene matrix in all rats. At the lower RPP level, RIHP was similar in both groups of rats (5.2+/-0.2 mm Hg for female, and 5.5+/-0.4 mm Hg for male), whereas fractional excretion of sodium (FENa) was significantly lower (P < .05) in male (1.10+/-0.27%) as compared to female (2.23+/-0.32%) rats at similar lower RPP. Allowing RPP to increase from 100 to 120 mm Hg resulted in similar increases in FENa (deltaFENa), urine flow rate (deltaV), and RIHP (deltaRIHP) in both groups of rats. The deltaFENa, deltaV, and deltaRIHP were 1.67+/-0.43%, 38.45+/-4.74 microL/min/g kidney weight, and 2.7+/-0.2 mm Hg for female, and 1.79+/-0.42%, 30.40+/-4.37 microl/min/g kidney weight, and 2.8+/-0.3 mm Hg for male rats. In conclusion, RIHP is similar in female and male SD rats at similar RPP levels. Both female and male SD rats increase RIHP and sodium excretion similarly in response to increases in RPP. The lower basal FENa in male as compared to female rats may play an important role in the more significant elevation of blood pressure in males with age.
本研究的目的是比较雌性和雄性Sprague-Dawley（SD）大鼠的肾间质静水压（RIHP）和钠排泄情况。测定了雌性（n = 13）和雄性（n = 8）SD大鼠的RIHP和压力性钠尿反应。肾灌注压（RPP）控制在两个水平（100和120 mmHg）。在每个水平进行清除率测定，并使用长期植入的聚乙烯基质测量所有大鼠的RIHP。在较低的RPP水平，两组大鼠的RIHP相似（雌性为5.2±0.2 mmHg，雄性为5.5±0.4 mmHg），而在相似的较低RPP下，雄性大鼠的钠分数排泄（FENa）显著低于雌性大鼠（P <.05）（雄性为1.10±0.27%，雌性为2.23±0.32%）。使RPP从100 mmHg增加到120 mmHg导致两组大鼠的FENa（ΔFENa）、尿流率（ΔV）和RIHP（ΔRIHP）有相似的增加。雌性大鼠的ΔFENa、ΔV和ΔRIHP分别为1.67±0.43%、38.45±4.74 μL/min/g肾重和2.7±0.2 mmHg，雄性大鼠分别为1.79±0.42%、30.40±4.37 μL/min/g肾重和2.8±0.3 mmHg。总之，在相似的RPP水平下，雌性和雄性SD大鼠的RIHP相似。雌性和雄性SD大鼠对RPP升高的反应中，RIHP和钠排泄的增加相似。与雌性大鼠相比，雄性大鼠较低的基础FENa可能在雄性随着年龄增长血压更显著升高方面起重要作用。
