Purchase this article with an account.
P N Patil; Antimuscarinic effects of stereoisomers of tropicamide on rabbit iris sphincter.. Invest. Ophthalmol. Vis. Sci. 1978;17(1):65-68.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The antimuscarinic activity of optical isomers of tropicamide were compared on the isolated rabbit iris sphincter. The increasing concentrations of both the (--)- and (+)-isomer shifted the dose-response curve of carbachol to the right in a parallel fashion. The competitive reversible muscarinic blocking effects of both isomers were confirmed by pA2 plots. The pA2 values from the nonpigmented irides for (--)- and (+)-tropicamide were 7.88 and 6.18, respectively. Thus the (+)-isomer has only 1/50 the blocking activity of the (--)-isomer. Although both isomers are slightly less active in the pigmented iris, the activity difference between the isomers was high. From the nonpigmented iris, the blocking effect of the active (--)-tropicamide was readily reversed by washing, whereas reversal of this isomer's effect from the pigmented iris was relatively slow.
This PDF is available to Subscribers Only