Characterization of Muscarinic Receptor Involvement in Human Ciliary Muscle Cell Function

Abstract

ABSTRACT

Examination of signalling pathways involved in muscarinic responses in bovine ciliary muscle using YM‐254890, an inhibitor of the Gq/11 protein

“…Can we propose a similar signalling mechanism involving M 3 receptors, G q/11 and NSCCs for the ciliary muscle in mammalian species other than the bovine? The abundant localization of M 3 receptors (or at least of its mRNA) in the ciliary muscle has been reported in the human eye ( Pang et al ., 1993 , 1994 ; Gupta et al ., 1994 ; Matsumoto et al ., 1994 ) and the monkey eye ( Barany et al ., 1982 ; Barany, 1985 ; Gabelt et al ., 1990 ; Poyer and Kaufman, 1993 ) as well as in the bovine eye (Figure 11; see also Masuda et al ., 1998 ). The lack or extreme paucity of voltage‐gated Ca 2+ entry pathways has also been demonstrated in the ciliary muscle of the human ( Suzuki, 1983 ) and dog ( Ito and Yoshitomi, 1986 ).…”

Effects of Pirenzepine on Pupil Size and Accommodation in Rhesus Monkeys

“…There have been very few M 1 receptors localized to the ciliary muscle in many species, including chick (Yin GC, et al IOVS 2003;44:ARVO E-Abstract 4339), bovine, 35 dog, 36 rhesus monkey, 13 and human. 16,37 Therefore, it is likely that pirenzepine works through a nonselective mechanism in concentrations of 0.02% to 2%, when delivered subconjunctivally.…”

“…13 In vivo in rhesus monkeys, accommodation and pupil constriction elicited by pilocarpine are antagonized by continuous intracameral perfusion of 1.4 M pirenzepine (0.059% solution), 14 and responses elicited by aceclidine are antagonized by 7 M pirenzepine (0.3% solution). 16 At these relatively high concentrations, it is likely that pirenzepine acts through nonselective antagonism of the ciliary muscle through M 3 receptors. 13,14,15 Pirenzepine has been shown to reduce the progression of myopia in animal studies.…”

A current review of olanzapine's safety in the geriatric patient: from pre-clinical pharmacology to clinical data

“…Peripheral hM 3 receptors are found in very high concentrations in exocrine glands, where stimulation may produce salivation, lacrimation, and sweating and, conversely, blockade might be expected to produce dry mouth, dry eyes and dry skin. hM 3 receptors are found in moderate concentrations in ocular ciliary muscle and peripheral smooth muscle, where stimulation may produce increased ocular¯uid out¯ow, contraction of intestinal smooth muscle and urinary bladder contractions and blockade may produce acute exacerbation of glaucoma, constipation and urinary bladder atony (Pang et al, 1994;Ehlert and Thomas, 1995;Mutschler et al, 1995;Erickson and Schroeder, 2000). hM 4 receptors are predominately localized to the basal ganglia and cerebral cortex with the highest concentrations observed in neostriatum, olfactory tubercle and islands of Callej, suggesting an important role in extrapyramidal function (Levey, 1993;Yasuda et al, 1993).…”