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Analysis of responses to serotonin in the pulmonary vascular bed of the cat.

Publication ,  Journal Article
McMahon, TJ; Hood, JS; Nossaman, BD; Kadowitz, PJ
Published in: J Appl Physiol (1985)
July 1993

Pulmonary vascular responses to serotonin (5-hydroxytryptamine; 5-HT) were investigated in the intact-chest cat under constant-flow conditions. Injections of 5-HT into the perfused lobar artery in doses of 1-30 micrograms caused dose-related increases in lobar arterial pressure and, at doses of 3-30 micrograms, decreases in systemic arterial pressure. Left atrial pressure was not changed, and responses to 5-HT were not altered by a thromboxane receptor blocking agent. Responses to 5-HT were blocked by ketanserin in doses that did not alter responses to agonists that increase pulmonary vascular resistance by various mechanisms. The ketanserin-induced blockade was not surmountable and at a dose of 0.5 mg/kg iv persisted for > 4 h. Prazosin and yohimbine, selective alpha 1- and alpha 2-adrenoceptor antagonists, were without effect on the pressor response to 5-HT, and ketanserin did not reduce responses to norepinephrine or the alpha 1-agonists, phenylephrine and methoxamine. 5-HT and the thromboxane mimic, U-46619, produced large increases in pulmonary vascular resistance; however, U-46619 was 300 times more potent than 5-HT. 5-HT increased lobar arterial pressure when the lung was perfused with dextran, and increases in lobar arterial pressure in response to 5-HT were not diminished when lobar ventilation was interrupted but were enhanced by N omega-nitro-L-arginine methyl ester and to a small extent by meclofenamate. The present data suggest that increases in pulmonary vascular resistance in the cat in response to 5-HT are due to activation of an S2 receptor in undefined "resistance vessel elements." These data suggest that pulmonary vasoconstrictor responses to 5-HT may be modulated to a small extent by release of a vasodilator prostaglandin and endothelium-derived nitric oxide but are not dependent on activation of thromboxane receptors, changes in bronchomotor tone, and interaction with alpha 1-receptors or with formed elements in blood.

Duke Scholars

Published In

J Appl Physiol (1985)

DOI

ISSN

8750-7587

Publication Date

July 1993

Volume

75

Issue

1

Start / End Page

93 / 102

Location

United States

Related Subject Headings

  • Vasoconstrictor Agents
  • Vascular Resistance
  • Thromboxane A2
  • Serotonin
  • Pulmonary Circulation
  • Prostaglandin Endoperoxides, Synthetic
  • Physiology
  • Norepinephrine
  • NG-Nitroarginine Methyl Ester
  • Muscle Tonus
 

Citation

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McMahon, T. J., Hood, J. S., Nossaman, B. D., & Kadowitz, P. J. (1993). Analysis of responses to serotonin in the pulmonary vascular bed of the cat. J Appl Physiol (1985), 75(1), 93–102. https://doi.org/10.1152/jappl.1993.75.1.93
McMahon, T. J., J. S. Hood, B. D. Nossaman, and P. J. Kadowitz. “Analysis of responses to serotonin in the pulmonary vascular bed of the cat.J Appl Physiol (1985) 75, no. 1 (July 1993): 93–102. https://doi.org/10.1152/jappl.1993.75.1.93.
McMahon TJ, Hood JS, Nossaman BD, Kadowitz PJ. Analysis of responses to serotonin in the pulmonary vascular bed of the cat. J Appl Physiol (1985). 1993 Jul;75(1):93–102.
McMahon, T. J., et al. “Analysis of responses to serotonin in the pulmonary vascular bed of the cat.J Appl Physiol (1985), vol. 75, no. 1, July 1993, pp. 93–102. Pubmed, doi:10.1152/jappl.1993.75.1.93.
McMahon TJ, Hood JS, Nossaman BD, Kadowitz PJ. Analysis of responses to serotonin in the pulmonary vascular bed of the cat. J Appl Physiol (1985). 1993 Jul;75(1):93–102.

Published In

J Appl Physiol (1985)

DOI

ISSN

8750-7587

Publication Date

July 1993

Volume

75

Issue

1

Start / End Page

93 / 102

Location

United States

Related Subject Headings

  • Vasoconstrictor Agents
  • Vascular Resistance
  • Thromboxane A2
  • Serotonin
  • Pulmonary Circulation
  • Prostaglandin Endoperoxides, Synthetic
  • Physiology
  • Norepinephrine
  • NG-Nitroarginine Methyl Ester
  • Muscle Tonus