Mechanisms in the pressor effects of hepatic portal venous fatty acid infusion

Roger J. Grekin, Craig J. Dumont, Alan P. Vollmer, Stephanie W. Watts, R. Clinton Webb

Research output: Contribution to journalArticle

58 Scopus citations

Abstract

Portal venous infusion of oleate solution has pressor effects. We have examined efferent mechanisms, measured the response to sustained infusion, and determined the effect of linoleate. Eight conscious animals received concurrent infusions of prazosin or vehicle with portal venous infusion of oleate. Oleate alone increased mean arterial pressure from 109.0 ± 4.1 to 123.0 ± 5.8 mmHg (P = 0.02), whereas no increase in blood pressure occurred when oleate was infused with prazosin. In 10 rats, concurrent infusion of losartan had no effect on the presser activity of portal oleate infusion. Twenty-two animals received portal oleate or vehicle as a continuous infusion for 7 days. Mean arterial pressure (126.1 ± 2.0 vs. 107.8 ± 2.6 mmHg, P < 0.001) and heart rate (383 ± 5 vs. 366 ± 5, P = 0.0257) were increased in oleate-infused animals. No differences in plasma fatty acids, glucose, insulin, pressor hormones, liver enzymes, or in vitro arterial pressor responsiveness were observed. Portal venous infusion of linoleate increased arterial pressure by 12.2 ± 3.2 mmHg (P = 0.033). These results indicate that α-adrenergic activity is necessary for the acute pressor effects of portal oleate, that sustained portal oleate infusion results in persistent blood pressure elevation, and that other long-chain fatty acids besides oleate have pressor effects.

Original languageEnglish (US)
Pages (from-to)R324-R330
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume273
Issue number1 42-1
StatePublished - Jul 1 1997
Externally publishedYes

Keywords

  • Angiotensin
  • Hypertension
  • Obesity
  • Sympathetic activity

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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    Grekin, R. J., Dumont, C. J., Vollmer, A. P., Watts, S. W., & Webb, R. C. (1997). Mechanisms in the pressor effects of hepatic portal venous fatty acid infusion. American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 273(1 42-1), R324-R330.