L-methionine enhances the contractile responses of rat uterine smooth muscle to acetylcholine and high KCl

The contractile responses of isolated uterine smooth muscle from estradiol-treated ovariectomized rats to acetylcholine and high KCl in Ca-depleted modified Locke-Ringer (without CaCl2 and with 0.1 mM EGTA) solution on addition of CaCl2 (final concentration, 5 mM) are used as an indicator of Ca influx through the Ca channel. L-Methionine significantly enhanced these responses in the absence and presence of 3-deazaadenosine plus homocysteine thiolactone, blockers of methylation. These findings suggest that methylations of some components in isolated uterine smooth muscle seem to be important in stimulation-contraction coupling in the muscle.