J. Navarro et al., HORMONAL, RENAL, AND METABOLIC ALTERATIONS DURING HYPERTENSION INDUCED BY CHRONIC INHIBITION OF NO IN RATS, American journal of physiology. Regulatory, integrative and comparative physiology, 36(6), 1994, pp. 180001516-180001521
The evolution of renal excretory function and circulating vasoactive s
ystems was studied during progressive increases in blood pressure (BP)
induced in rats by oral administration of N-G-nitro-L-arginine methyl
ester (L-NAME; 5-30 mg/100 ml) for 5 wk. L-NAME induced a stepped ele
vation (P < 0.05) in BP levels without changing creatinine clearance,
urine flow, or sodium excretion rate along the study. Reductions (P <
0.05) in plasma renin activity and plasma aldosterone concentration we
re found only during treatment with 30 mg/100 ml of L-NAME. Plasma nor
epinephrine and epinephrine concentrations were elevated (P < 0.05) in
the last week of the study. Plasma concentrations of endothelin-1 and
urinary excretion of prostaglandin E(2), 6-ketoprostaglandin F1(alpha
), and thromboxane B-2 were not significantly affected by L-NAME. Simi
larly, no changes in plasma concentrations of glucose, insulin, total
cholesterol, or triglycerides were observed. In summary, during long-t
erm administration of L-NAME, progressive increases in BP levels were
observed without changes in either sodium excretion or enhanced circul
ating vasoconstrictor activity. Thus, it is likely that inhibition of
synthesis of nitric oxide (NO) in the vasculature leads to an imbalanc
e between the tonic relaxing action of NO and the influences of vasoco
nstrictor agents even when the latter remain at normal levels.