In:
Journal of Pharmacy and Pharmacology, Oxford University Press (OUP), Vol. 49, No. 11 ( 2011-04-12), p. 1121-1125
Abstract:
Two geometric isomers, the Z- and the E- forms, can be separated from synthetic mixtures of butylidenephthalide (Bdph). Z-Bdph (50–100 μm) non-competitively inhibited Ca2+-induced contractions in depolarized (K+, 60 mm) guinea-pig ileum longitudinal smooth muscle, with a pD2' value of 3.88 ± 0.20 (n = 5). However, E-Bdph (20–100 μm) competitively inhibited these contractions with a pA2 value of 4.56 ± 0.18 (n = 5) which was significantly (P & lt; 0.05) greater than the pD2' value of Z-Bdph. In contrast, the two isomers had no stereoselective inhibitory action on Ca2+ influx through pre- or post-junctional membranes of cholinergic nerve endings from which the transmitter acetylcholine is released or on Ca2+ release from intracellular stores. Therefore, the trans-Z and cis-E forms of Bdph might have geometric stereoselectivity for voltage-dependent calcium channels (VDC) in guinea-pig longitudinal smooth muscle. Both isomers might inhibit more selectively the contractile twitch responses evoked by electrical stimulation than by cumulative acetylcholine-or carbachol-induced transient contractions in guinea-pig ileum longitudinal smooth muscle.
Type of Medium:
Online Resource
ISSN:
2042-7158
,
0022-3573
DOI:
10.1111/j.2042-7158.1997.tb06053.x
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2011
detail.hit.zdb_id:
2041988-0
detail.hit.zdb_id:
2050532-2
SSG:
15,3
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