Cardiovascular actions of dogfish urotensin II in the dogfish Scyliorhinus canicula

N. Hazon, C. Bjenning, J. M. Conlon

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)

Abstract

Bolus injections of synthetic dogfish urotensin II (0.1-1.0 nmol) into the celiac artery of the conscious dogfish Scyliorhinus canicula (n = 8) resulted in sustained and dose-dependent increases in arterial blood pressure and pulse pressure. A maximum rise in mean arterial pressure of 10.5 ± 1.2 mmHg (equivalent to 38.6 ± 4.2% over mean basal values) and a maximum increase in pulse pressure of 3.9 ± 0.8 mmHg was elicited by injection of 0.5 nmol of peptide. In comparison, a bolus injection of epinephrine (5 nmol) elicited a rise of 24.8 ± 3.3% in mean arterial pressure. Bolus injection of 0.5 nmol synthetic goby (Gillichthys mirabilis) urotensin II under the same conditions did not elicit a significant hypertensive response. When dogfish urotensin II (0.5 nmol) was administered 3 min after an intra-arterial injection of phentolamine, the rise in arterial blood pressure was completely abolished. Dogfish urotensin II produced a dose-dependent contraction (pD2 = 6.58 ± 0.07; n = 8) of isolated rings of vascular muscle prepared from the first afferent branchial artery of the dogfish. A maximum contractile force of 1.3 mN was produced by 10-5 M peptide. The urotensin II-induced contraction of the vascular rings was unaffected by pretreatment with tetrodotoxin (1 μM) or indomethacin (14 μM). It is concluded that urotensin II has potent hypertensive activity in the dogfish that is mediated, at least in part, through release of catecholamines, but the sustained nature of the pressor response suggests that the peptide may have a direct action on the heart.

Original languageEnglish
Pages (from-to)R573-R576
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume265
Issue number3 34-3
DOIs
Publication statusPublished - 1993
Externally publishedYes

Keywords

  • circulating catecholamines
  • elasmobranch
  • gill artery
  • myotropic peptide
  • vasoconstrictor

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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