Top 50 words repeated twice, next 100 once, plus phrases. It is through such an action on smooth muscle that our ideas about BZ ant other potent antlcholinergica have developed. Atroplne ant BZ were alike in bladlag capacity to these altes. This suggests that, although events relates to muscarinic receptor action are blocked by antimnacarinic drugs, other actions may be stimulated. It is known that calcium ions activate phospholipase-C and stimulate the turnover of phoapholiplds, such as triphosphoinooltides, in excitable membranes.
Calcium ions have diverse functions in the regulation of cell function.
A small rice in intracellular calcium will produce a sharp rise in Kid conductance, hyperpolarization, ant tepreselon of excitability. Although the effects of BZ are qualitatively similar to the pharmacologic actions of atropine ant scopolamine, the potency and especially the duration of action of BZ are considerably greater. Waldo This has led to the hypothesis of a direct effect on presynaptic muscarinic receptors that regulate ACh release. Hey appear to be equally effective peripherally, when comparisons are based on affinity for muscarinic binding sites. Calcium ion contents can be regulated by any of the membrane systems that are in contact with the cytosol, e.g., plaama membrane, endoplaamic reticulum, and mitochondrial inner membrane.