PURPOSE Muscarinic acetylcholine receptors (mAChRs) have been implicated in the control of myopia in humans and in animal models. This study was conducted to determine whether mAChRs influence the growth of the chick sclera and, if so, which mAChR subtypes are involved. METHODS Sclera and scleral chondrocytes from normal and form-deprived eyes of 10- to 14-day-old chicks were treated with a t...

PURPOSE Previous studies have indicated that muscarinic acetylcholine receptors (mAChR) may be present in an unexpected, unique location and play a singular role in cellular growth regulation of rabbit corneal epithelium that may be of general physiologic significance if found in other cells. The purpose of this study was to examine rabbit corneas and corneal cells in culture to determine mAChR...

Previously we have shown that G protein-coupled receptor kinase (GRK) 6 plays a major role in the regulation of the human M3 muscarinic acetylcholine receptor (M3 mAChR) in the human neuroblastoma SH-SY5Y. However, 30-fold overexpression of the catalytically inactive, dominant-negative K215RGRK6 produced only a 50% suppression of M3 mAChR phosphorylation and desensitization. Here, we have attem...

Antagonists of the muscarinic acetylcholine receptors (mAChRs) were among the first treatments for Parkinson's disease. However, the clinical utility of mAChR antagonists is limited by adverse effects associated with the blockade of multiple mAChR subtypes. Understanding the roles of specific mAChR subtypes in regulating basal ganglia and motor function could lead to the development of novel ag...

The muscarinic acetylcholine receptor (mAChR) has been considered one of the neurotransmitter receptors regulating hippocampal synaptic plasticity, which likely plays a critical role in learning and memory. In previous studies, however, muscarinic agonists were used at relatively high concentrations, and the subtype selectivity of muscarinic antagonists was not satisfactory. Thus, it remains to...

Endocytosis of agonist-activated G protein-coupled receptors (GPCRs) is required for both resensitization and recycling to the cell surface as well as lysosomal degradation. Thus, this process is crucial for regulation of receptor signaling and cellular responsiveness. Although many GPCRs internalize into clathrin-coated vesicles in a dynamin-dependent manner, some receptors, including the M(2)...

The M(3) subtype of muscarinic acetylcholine receptors (M(3)-mAChR) plays a protective role in myocardial ischemia and microRNAs (miRNAs) participate in many cardiac pathophysiological processes, including ischemia-induced cardiac injury. However, the role of miRNAs in M(3)-mAChR mediated cardioprotection remains unexplored. The present study was designed to identify miRNAs that are involved in...

There are 9 cysteine residues in the rat m1 muscarinic acetylcholine receptor (mAChR) that are conserved among all five mammalian mAChR subtypes sequenced to date. To study the role of these cysteines in rat m1 mAChR function, site-directed mutagenesis was used to convert each Cys residue to Ser, and the mutant receptor genes were transfected into mAChR-deficient Chinese hamster ovary (CHO) cel...

Yang, Qing, Andrew D. Sumner, Henry L. Puhl, and Victor Ruiz-Velasco. M1 and M2 muscarinic acetylcholine receptor subtypes mediate Ca channel current inhibition in rat sympathetic stellate ganglion neurons. J Neurophysiol 96: 2479 –2487, 2006; doi:10.1152/jn.00093.2006. Muscarinic acetylcholine receptors (mAChRs) are known to mediate the acetylcholine inhibition of Ca channels in central and pe...

Margas W, Mahmoud S, Ruiz-Velasco V. Muscarinic acetylcholine receptor modulation of Mu ( ) opioid receptors in adult rat sphenopalatine ganglion neurons. J Neurophysiol 103: 172–182, 2010. First published November 4, 2009; doi:10.1152/jn.00295.2009. The sphenopalatine ganglion (SPG) neurons represent the parasympathetic branch of the autonomic nervous system involved in controlling cerebral bl...