Nitric oxide may be required to prevent hypertension at the onset of diabetes

Sharyn M. Fitzgerald, Michael W. Brands

Research output: Contribution to journalArticlepeer-review

49 Scopus citations

Abstract

Nitric oxide (NO) plays an important role in the regulation of vascular tone, and evidence suggests that endothelial-dependent relaxation, possibly mediated via NO, is impaired in diabetes. However, the role of the endothelium in arterial pressure control early in diabetes, before dysfunction develops, is not known. This was evaluated in the present study by comparing the responses to induction of diabetes in vehicle-treated rats (D, n = 7) vs. rats chronically treated with N(G)-nitro-L-arginine methyl ester (L-NAME; D+L, n = 8). A nondiabetic group also was treated with L-NAME (L, n = 7) to control for L-NAME effects over time, independent of diabetes. After baseline measurements, rats were given either vehicle or L-NAME (10 μg·kg-1·min-1 iv) infusion throughout the experiment. Six days later, streptozotocin (60 mg/kg iv) was administered, followed by a 3-wk diabetic study period. Induction of diabetes in the D+L rats caused a marked and progressive increase in mean arterial pressure throughout the diabetic period, averaging ~70 mmHg greater than in the D rats and ~20 mmHg greater than in the L rats. Glomerular filtration rate and renal plasma flow tended to increase during diabetes, but this trend was reversed in the D+L rats. In addition, plasma renin activity increased in the D and D+L rats during week I of diabetes but then returned to control in the D rats, while continuing to increase in the D+L rats. These results suggest that, in the early stages of diabetes, NO synthesis is important to prevent hypertension from developing, possibly through actions to maintain glomerular filtration and suppress renin secretion.

Original languageEnglish (US)
Pages (from-to)E762-E768
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume279
Issue number4 42-4
DOIs
StatePublished - 2000
Externally publishedYes

Keywords

  • Angiotensin II
  • Arterial pressure
  • Glucose
  • N(G)-nitro-L-arginine methyl ester
  • Vasodilation

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Physiology (medical)

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