Thromboxane-B2, prostaglandin-E2 and hypertension in the rat 2-kidney 1-clip model: a possible mechanism of the garlic induced hypotension

Serum collected from unilaterally clipped and unclipped rats before and after treatment with water, garlic or cilazapril and subsequent to measuring blood pressure was assayed for thromboxane-B2 and prostagtandin-E2. The unclipped rats' thromboxane-B2 and prostaglandin-E2 levels were about 23 ng/ml and 2 ng/ml, respectively, and blood pressure was 126 +/- 3 mm Hg. These values were not affected by either water or garlic administration. The clipped rats' thromboxane-B2 and prostaglandin-E2 concentrations were close to 34 ng/ml and 4 ng/ml, respectively, and declined only in response to garlic (by 15 ng/ml and 3 ng/ml) and cilazapril (by 12 ng/ml and 1.5 ng/ml). The brood pressure of these rats was 196 +/- 7 mmHg and again was reduced only by garlic to 169 +/- 14 mmHg and cilazapril to 137 +/- 5 mmHg. The no-treatment and water-treatment readings were significantly higher in the clipped rats. The data suggest that prostanoid system activity in the 2-kidney 1-clip rat is enhanced and mostly toward maintaining the hypertension. Furthermore, the brood pressure lowering effects of garlic and cilazapril might have been induced partially by a greater reduction in the synthesis of vasoconstrictor prostanoids. (C) 2001 Harcourt Publishers Ltd.