Reduction of obesity, as induced by leptin, reverses endothelial dysfunction in obese (Lep(ob)) mice

Bradford Winters, Zhiping Mo, Esther Brooks-Asplund, Soonyul Kim, Artin Shoukas, Dechun Li, Daniel Nyhan, Dan E. Berkowitz

Research output: Contribution to journalArticle

Abstract

Obesity is a major health care problem and is associated with significant cardiovascular morbidity. Leptin, a neuroendocrine hormone released by adipose tissue, is important in modulating obesity by signaling satiety and increasing metabolism. Moreover, leptin receptors are expressed on vascular endothelial cells (ECs) and mediate angiogenesis. We hypothesized that leptin may also play an important role in vasoregulation. We investigated vasoregulatory mechanisms in the leptin-deficient obese (ob/ob)mouse model and determined the influence of leptin replacement on endothelial-dependent vasorelaxant responses. The direct effect of leptin on EC nitric oxide (NO) production was also tested by using 4,5-diaminofluorescein-2 diacetate staining and measurement of nitrate and nitrite concentrations. Vasoconstrictor responses to phenylephrine, norepinephrine, and U-46619 were markedly enhanced in aortic rings from ob/ob mice and were modulated by NO synthase inhibition. Vasorelaxant responses to ACh were markedly attenuated in mesenteric microvessels from ob/ob mice. Leptin replacement resulted in significant weight loss and reversal of the impaired endothelial-dependent vasorelaxant responses observed in ob/ob mice. Preincubation of ECs with leptin enhanced the release of NO production. Thus leptin-deficient ob/ob mice demonstrate marked abnormalities in vasoregulation, including impaired endothelial-dependent vasodilation, which is reversed by leptin replacement. These findings may be partially explained by the direct effect of leptin on endothelial NO production. These vascular abnormalities are similar to those observed in obese, diabetic, leptin-resistant humans. The ob/ob mouse may, therefore, be an excellent new model for the study of the cardiovascular effects of obesity.

Original languageEnglish (US)
Pages (from-to)2382-2390
Number of pages9
JournalJournal of applied physiology
Volume89
Issue number6
StatePublished - Dec 20 2000

Keywords

  • Diabetes
  • Nitric oxide

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Reduction of obesity, as induced by leptin, reverses endothelial dysfunction in obese (Lep(ob)) mice'. Together they form a unique fingerprint.

  • Cite this