INTRARENAL VASOCONSTRICTION DURING HYPERCHLOREMIA - ROLE OF THROMBOXANE
INTRARENAL VASOCONSTRICTION DURING HYPERCHLOREMIA - ROLE OF THROMBOXANE
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DOI：
10.1152/ajprenal.1989.256.1.f152
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发表时间：
1989-01-01
影响因子：
--
通讯作者：
WELCH, WJ
中科院分区：
文献类型：
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作者：
BULLIVANT, EMA;WILCOX, CS;WELCH, WJ
The role of thromboxane (Tx) in chloride-induced renal vasoconstriction was studied in Munich-Wistar rats. Hyperchloremia (induced by changing an intra-aortic, super-renal infusion of 1.2 M Na acetate to 1.2 M NaCl) reduced the glomerular filtration rate (GFR) by 31 .+-. 3% (P < 0.001; n = 27), and the clearance of p-aminohippurate (CPAH) by 36 .+-. 4% (P < 0.01). The Tx synthetase antagonists (25 mg/kg) UK-38,485 or OKY-046 prevented these changes. Pretreatment with indomethacin (5 mg/kg) also prevented Cl-induced changes in GFR and CPAH and blunted (P < 0.05) the Cl-induced increase in renal vascular resistance (RVR, vehicle +55.+-. 11%, n = 8, indomethacin +27 .+-. 7%, n = 6). Hyperchloremia reduced the hydraulic pressures (mmHg) in the outer cortical efferent arteriolar vessels (PEA, 23.9 .+-. 1.6 vs. 17.9 .+-. 0.9; P < 0.01) and proximal tubules (PT, 21.1 .+-. 1.5 vs. 15.8 .+-. 1.4; P < 0.01) but not in the glomerular capillaries (PGC, 47.0 .+-. 2.5 vs 49.5 .+-. 2.2; NS). Therefore the hydraulic pressure drop across the glomerular capillaries (PGC = PT) increased (24.9 .+-. 2.8 vs. 34.6 .+-. 2.9; P < 0.02). UK-38,485 prevented significant Cl-induced changes in these pressures. The calculated resistances of the afferent and efferent arterioles both increased during hyperchloremia (+56 .+-. 19%; P < 0.05 and +195 .+-. 66%; P < 0.01, respectively) but were blunted after UK-38,45 (+23 .+-. 8 and +21 .+-. 10%, respectively). In conclusion, products of cyclooxygenase and Tx synthetase mediate Cl-induced reductions in GFR and contribute to the increase in RVR by actions on the afferent and efferent arterioles.
