In:
Journal of Cerebral Blood Flow & Metabolism, SAGE Publications, Vol. 3, No. 2 ( 1983-06), p. 238-245
Abstract:
The effects of prostacyclin (PGI 2 ) were studied in isolated cat basilar and middle cerebral arteries and in human pial arteries. In feline vessels with low resting tension, PGI 2 had a contractile effect that reached a maximum of 132% (basilar artery) and 23% (middle cerebral artery) of the potassium-induced (127 m M) contraction. In potassium-contracted feline vessels, PGI 2 caused a further contraction. When these vessels were contracted by PGF 2α , PGI 2 induced relaxation, which was most marked in the middle cerebral artery. PGI 2 consistently relaxed the middle cerebral artery contracted by the prostaglandin endoperoxide analogue U-44069, whereas the basilar artery was almost unaffected. In human pial arteries with low resting tension, PGI 2 had no effects in concentrations below 10 −6 M, whereas higher concentrations induced contractions. In potassium-contracted (35 or 127 m M) preparations, PGI 2 in concentrations below 10 −6 M produced relaxation; in higher concentrations further contraction was induced. Human pial arteries contracted by PGF 2α , U-44069, noradrenaline, or 5-hydroxytryptamine consistently relaxed in response to PGI 2 ( 〈 10 −6 M). The PGI 2 metabolite 6-keto-PGE 1 had effects similar to those of PGI 2 , but proved to be less potent on human pial vessels. 6-Keto-PGF 1α was ineffective, whereas 6, 15-diketo-PGF 1α had minor relaxant effects. The results suggest that consideration must be given to regional as well as species differences concerning the cerebrovascular effects of PGI 2 .
Type of Medium:
Online Resource
ISSN:
0271-678X
,
1559-7016
DOI:
10.1038/jcbfm.1983.32
Language:
English
Publisher:
SAGE Publications
Publication Date:
1983
detail.hit.zdb_id:
2039456-1
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