Stier C T, Itskovitz H D, Chen Y H
Department of Pharmacology, New York Medical College Valhalla 10595.
Clin Exp Hypertens. 1993 Jan;15(1):105-23. doi: 10.3109/10641969309041614.
We measured urinary dopamine in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) before (days 0-6) and during high-salt diet, in the absence (days 6-10) and presence (days 10-14) of added L-dopa (2 mg/kg/day by gavage). Urinary excretion of sodium (UNaV) increased 20-fold during intake of chow containing 8% NaCl in both strains. Systolic blood pressure (SBP) of SHR increased slightly (9 +/- 4 mmHg; p < 0.05) on the high-salt diet, whereas SBP did not change in WKY. Urinary dopamine excretion was not different between strains in the basal state, and was as great or greater in SHR than WKY during high-salt intake with and without added L-dopa. SBP was unaffected by L-dopa administration and UNaV did not increase or differ between strains despite higher urinary dopamine excretion in SHR. We conclude that renal dopamine formation in vivo is not diminished in SHR, compared with WKY, on normal or high-salt diets, and that elevation of renal dopamine formation secondary to L-dopa administration is not associated with reductions in SBP or altered UNaV in these rats.
我们在自发性高血压大鼠（SHR）和正常血压的Wistar-Kyoto大鼠（WKY）中，于高盐饮食前（第0 - 6天）以及高盐饮食期间，在未添加（第6 - 10天）和添加左旋多巴（通过灌胃给予2 mg/kg/天）（第10 - 14天）的情况下，测量了尿多巴胺。在两种品系大鼠摄入含8%氯化钠的食物期间，尿钠排泄量（UNaV）增加了20倍。高盐饮食时，SHR的收缩压（SBP）略有升高（9±4 mmHg；p < 0.05），而WKY的SBP未发生变化。基础状态下，两品系大鼠的尿多巴胺排泄无差异，在高盐摄入期间，无论是否添加左旋多巴，SHR的尿多巴胺排泄量与WKY相同或更高。左旋多巴给药对SBP无影响，尽管SHR的尿多巴胺排泄量更高，但两品系大鼠的UNaV未增加或存在差异。我们得出结论，与WKY相比，在正常或高盐饮食条件下，SHR体内肾多巴胺的生成并未减少，并且左旋多巴给药继发的肾多巴胺生成增加与这些大鼠的SBP降低或UNaV改变无关。
