{alpha}-Toxin-permeabilised rabbit fetal ductus arteriosus is more sensitive to Ca2+ than aorta or main pulmonary artery

doi:10.1016/S0008-6363(96)00171-X

Cardiovascular Research 1997 33(1):223-229; doi:10.1016/S0008-6363(96)00171-X
© 1997 by European Society of Cardiology

This Article

	Full Text
	FREE Full Text (PDF)
	E-letters: Submit a response
	Alert me when this article is cited
	Alert me when E-letters are posted
	Alert me if a correction is posted

Services

	Email this article to a friend
	Similar articles in this journal
	Similar articles in PubMed
	Alert me to new issues of the journal
	Add to My Personal Archive
	Download to citation manager
	Request Permissions
	Disclaimer

Google Scholar

	Articles by Crichton, C. A.
	Articles by Smith, G. L.
	Search for Related Content

PubMed

	PubMed Citation
	Articles by Crichton, C. A.
	Articles by Smith, G. L.

Social Bookmarking

	What's this?

${alpha}$ -Toxin-permeabilised rabbit fetal ductus arteriosus is more sensitive to Ca²⁺ than aorta or main pulmonary artery

Catherine A. Crichton^a^,*, Gordon C.S. Smith^b and Godfrey L. Smith^a

^aInstitute of Biological and Life Sciences, West Medical Building, Glasgow University, Glasgow, G12 8QQ, UK
^bDept of Obstetrics and Gynaecology, Glasgow Royal Infirmary, Glasgow, UK

Objectives: The Ca²⁺ sensitivity of contractile protein-generatedtension production was measured in the smooth muscle of therabbit ductus arteriosus and compared with two neighbouringfetal blood vessels (main pulmonary artery and aorta). The effectof prostaglandin E₂ (PGE₂), 3-isobutyl-1-methylxanthine (IBMX,a phosphodiesterase inhibitor), cyclic adenosine 3',5'-monophosphate(CAMP) and forskolin (an activator of adenylate cyclase) onCa²⁺-activated force generated by preparations from ductus arteriosuswas also examined. Methods: Strips of smooth muscle from thethree vessels were permeabilised using crude ${alpha}$ -toxin from Staphylococcusaureus. The relationship between [Ca²⁺] and force productionwas then measured in the three tissues and the effect of PGE₂,cAMP, IBMX and forskolin was examined on submaximal Ca²⁺-activatedforce (0.3 µM Ca²⁺) in preparations from rabbit ductusarteriosus. Results: Permeabilised smooth muscle from fetalrabbit ductus arteriosus was significantly more sensitive toCa²⁺ (EC₅₀, 0.20 µM) than its two neighbouring blood vesselsaorta (EC₅₀, 0.52 µM) and main pulmonary artery (EC₅₀,0.72 µM). Submaximal Ca²⁺-activated force (0.3 µMCa²⁺) was depressed by PGE₂ (1 nM) in the presence of IBMX (10µM), by cAMP (10 and 100 µM) and by forskolin alone(0.1 µM and 1 µM). Conclusion: PGE₂-mediated depressionof Ca²⁺-activated force in the smooth muscle of the ductus arteriosusmay play a role in the maintenance of a patent ductus arteriosusin the fetus. The intrinsically high Ca²⁺ sensitivity of smoothmuscle contractile proteins may aid the sustained vasoconstrictionof the ductus when the PGE₂ levels fall after birth.

KEYWORDS ${alpha}$ -Toxin; Calcium sensitivity – Ductus arteriosus – Prostaglandin – cAMP – Rabbit, vascular myocytes – Rabbit arteries

^* Corresponding author. Tel. +44 141 330-5963; Fax +44 141 330-4612.

Add to CiteULike CiteULike Add to Connotea Connotea Add to Del.icio.us Del.icio.us What's this?

This article has been cited by other articles:

P. I. Aaronson, T. P. Robertson, G. A. Knock, S. Becker, T. H. Lewis, V. Snetkov, and J. P. T. Ward
Hypoxic pulmonary vasoconstriction: mechanisms and controversies
J. Physiol., January 1, 2006; 570(1): 53 - 58.
[Abstract] [Full Text] [PDF]