Abstract | OBJECTIVES: The purpose of this study was to determine the contribution of the functional changes in resistance vessels to the hypertension induced by chronic nitric oxide synthase inhibition in rats. Another goal of this study was to evaluate whether this model of hypertension is accompanied by changes in the activity of endothelium-derived hyperpolarizing factor ( EDHF). METHODS: RESULTS: Kidneys from L-NAME-induced hypertensive rats showed increased sensitivity to vasoconstrictors with a greater duration of the pressor responses at high doses and markedly up-shifted flow-pressure curve in comparison with that obtained in control kidneys. These differences disappeared when the kidneys from control and L-NAME-treated rats were infused with L-arginine. The kidneys from L-NAME-treated rats also showed a decreased responsiveness to acetylcholine with an augmented reactivity to nitroprusside. The acetylcholine dose-response curve was reduced in control preparations and greatly attenuated in L-NAME-treated preparations when the renal vasculature was preconstricted with potassium chloride. CONCLUSIONS: The changes in vascular reactivity observed in L-NAME-induced hypertensive rats may play an important role in the pathogenesis of this type of hypertension. Moreover, it is also suggested that long-term nitric oxide inhibition may be associated with increased activity of EDHF.
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Authors | F Vargas, A Osuna, A Fernández-Rivas |
Journal | Journal of hypertension
(J Hypertens)
Vol. 14
Issue 3
Pg. 373-9
(Mar 1996)
ISSN: 0263-6352 [Print] England |
PMID | 8723992
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Biological Factors
- endothelium-dependent hyperpolarization factor
- Arginine
- Nitric Oxide Synthase
- Acetylcholine
- NG-Nitroarginine Methyl Ester
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Topics |
- Acetylcholine
(pharmacology)
- Animals
- Arginine
(analogs & derivatives, pharmacology)
- Biological Factors
(physiology)
- Blood Vessels
(drug effects, physiopathology)
- Hypertension
(etiology, physiopathology)
- Kidney
(blood supply)
- Male
- NG-Nitroarginine Methyl Ester
- Nitric Oxide Synthase
(antagonists & inhibitors)
- Perfusion
- Rats
- Rats, Wistar
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