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Young, genetically hypertensive Lyon (LH) rats exhibited an increased renal in vivo turnover of norepinephrine and an elevated urinary excretion of thromboxane B 2 when compared with nonnotensive (LN) and low blood pressure (LL) controls. Therefore, the effects of norepinephrine (1.2 xlO" 8 to 9.6 xlO" 7 M) and of phenylephrine (5xlO~8 to 1.9x10"' M) on renal function and the urinary excretion of prostanoids were assessed in isolated perfused kidneys of 8-week-old LH, LN, and LL rats. In addition, the effects of norepinephrine were assessed before and during thromboxane A 2 /prostaglandin H 2 receptor blockade by AH23848 (4xlO~* M). Before drug infusion, LH kidneys differed from those of LN and LL controls by having an elevated renal vascular resistance and a decreased natriuresis and glomerular filtration rate; the urinary output of prostaglandin E 2 and F^, of 6-ketoprostaglandin F la , and of thromboxane B 2 was similar in the three strains. The constrictor effects of norepinephrine and phenylephrine were significantly increased in LH rat kidneys compared with LL but not with LN controls, and their pressure-natriuresis was markedly reduced. Norepinephrine and phenylephrine induced a 10-to 20-fold dose-dependent increase in the synthesis of the four prostanoids, which was more pronounced in LH than in LN and LL rats for thromboxane B 2 only. AH23848 infusion significantly reduced the vascular effects of norepinephrine and increased the natriuretic response of LH but not of LN and LL rat kidneys. In conclusion, isolated perfused kidneys from LH rats exhibit an increased production of thromboxane A 2 , which enhances the renal effects of norepinephrine and therefore could participate in the development of hypertension of the Lyon model. (Hypertension 1991;17:296-302)

This study suggests that cold preservation in HEH has a beneficial action in in vivo renal preservation and reduces tubular necrosis, interstitial inflammation, and fibrosis in these groups. In addition, PBR detection was correlated to the level of preservation integrity.

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