It was attempted to clarify the participation of K+ channels in the post-receptor mechanisms of the muscarinic and A1-adenosine receptor-mediated control of acetylcholine (ACh) release in the present study. Slices from the rat hippocampus were equilibrated with (3H)choline and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 V/cm, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium-outflow was investigated. Oxotremorine (Oxo, 0.1~10 micrometer), a muscarinic agonist, and N6-cyclopentyladenosine (CPA, 1~30 micrometer), a specific A1-adenosine agonist, decreased the ACh release in a dose-dependent manner, without affecting the basal rate of release. 4-aminopyridine (4AP), a specific A-type K+-channel blocker (1~100 micrometer), increased the evoked ACh release in a dose-related fashion, and the basal rate of release is increased by 3 and 100 micrometer. Tetraethylammonium (TEA), a non-specific K+-channel blocker (0.1~10 mM), increased the evoked ACh release in a dose-dependent manner without affecting the basal release. The effects of Oxo and CPA were not affected by 3 micrometer 4AP co-treatment, but 10 mM TEA significantly inhibited the effects of Oxo and CPA. 4AP (10 micrometer- and TEA (10 mM)-induced increments of evoked ACh release were completely abolished in Ca2+-free medium, but these were recovered in low Ca2+ medium. And the effects of K+-channel blockers in low Ca2+ medium were inhibited by Mg2+ (4 mM) and abolished by 0.3 micrometer tetrodotoxin (TTX). These results suggest that the changes in TEA-sensitive potassium channel permeability and the consequent limitation of Ca2+ influx are partly involved in the presynaptic modulation of the evoked ACh-release by muscarinic and A1-adenosine receptors of the rat hippocampus.
4-Aminopyridine ; Acetylcholine* ; Animals ; Electric Stimulation ; Hippocampus* ; Muscarinic Agonists ; Oxotremorine ; Permeability ; Potassium Channels ; Rats* ; Receptors, Muscarinic ; Tea ; Tetraethylammonium ; Tetrodotoxin

Cognitive deficit is frequently observed in patients with schizophrenia. It is significantly associated with functional outcome. In the past 20 years, due to significant advances on the concept of schizophrenia, cognitive deficit has been accepted as a core feature. In the DSM-5, cognitive deficit does not introduce diagnostic criteria of schizophrenia, but did one dimension of diagnosis of psychosis. Existing schizophrenia drugs are effective in treatment of positive symptoms of schizophrenia, but lack of effectiveness on improving cognitive function. Led by NIMH (National Institute of Mental Health), the MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) meeting was conducted in order to achieve consensus on measuring tools and neuropharmacological targets for clinical trials for development of new drugs for improvement of cognitive function in schizophrenia. At the MATRICS consensus meeting, glutamatergic modulators and nicotinic and muscarinic agonists are expected to be promising, but should be proven by a double-blind placebo-controlled multicenter study for patients.
Cognition ; Consensus ; Diagnosis ; Drug Therapy ; Humans ; Muscarinic Agonists ; National Institute of Mental Health (U.S.) ; Psychotic Disorders ; Schizophrenia*

The relationship between M3 cholinergic receptor agonist (carbachol) hyperstimulation-induced pancreatic acinar cellular injury and trypsinogen activation or NF-kappaB activation in rats was studied in vitro. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, the active protease inhibitor (pefabloc), and NF-kappaB inhibitor (PDTC) in vitro. Intracellular trypsin activity was measured by using a fluorogenic substrate. The cellular injury was evaluated by measuring the leakage of LDH from pancreatic acinar cells. The results showed that as compared with control group, 10(-3) mol/L carbachol induced a significant increase of the intracellular trypsin activity and the leakage of LDH from pancreatic acinar cells. Pretreatment with 2 mmol/L pefabloc could significantly decrease the activity of trypsin and the leakage of LDH from pancreatic acinar cells (P < 0.01) following the treatment with a high concentration of carbachol (10(-3) mol/L) in vitro. The addition of 10(-2) mol/L PDTC didn't result in a significant decrease in the activity of trypsin and the leakage of LDH from pancreatic acinar cells treated with a high concentration of carbachol (10(-3) mol/L) in vitro (P > 0.05). It was concluded that intracellular trypsinogen activation is likely involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro. NF-kappaB activation may not be involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro.
Carbachol/*pharmacology ; Cholinergic Agonists/pharmacology ; NF-kappa B/*metabolism ; Pancreas/metabolism ; Pancreas/*pathology ; Rats, Wistar ; Receptor, Muscarinic M3/agonists ; Trypsinogen/*metabolism

The autonomic nervous system contributes to prostate cancer proliferation and metastasis. However, the exact molecular mechanism remains unclear. In this study, muscarinic acetylcholine receptor M1 (CHRM1) expression was measured via immunohistochemical analysis in human prostate cancer tissue array slides. PC-3, LNCaP, and A549 cells were treated with pirenzepine or carbachol, and the cell migration and invasion abilities were evaluated. Western blotting and quantitative real-time PCR were performed to measure GLI family zinc finger 1 (GLI1), patched 1 (PTCH1), and sonic hedgehog (SHH) expression levels. High expression of CHRM1 was found in early-stage human prostate cancer tissues. In addition, the selective CHRM1 antagonist pirenzepine inhibited PC-3, LNCaP, and A549 cell migration and invasion, but the agonist carbachol promoted the migration and invasion of these three cell lines. Muscarinic signaling can be relayed by hedgehog signaling. These data show that CHRM1 is involved in the regulation of prostate cancer migration and invasion through the hedgehog signaling pathway.
Carbachol/pharmacology* ; Cell Movement/genetics* ; Cell Proliferation ; Hedgehog Proteins/genetics* ; Humans ; Male ; Muscarinic Agonists/pharmacology* ; Muscarinic Antagonists/pharmacology* ; Patched-1 Receptor/genetics* ; Pirenzepine/pharmacology* ; Prostatic Neoplasms/pathology* ; Receptor, Muscarinic M1/genetics* ; Zinc Finger Protein GLI1/genetics*

No abstract available.
Adrenergic beta-3 Receptor Agonists/therapeutic use ; Humans ; Muscarinic Antagonists/therapeutic use ; Precision Medicine/methods/*trends ; Urinary Bladder, Overactive/*therapy

BACKGROUND/AIMS: Gastric peristalsis begins in the orad corpus and propagates to the pylorus. Directionality of peristalsis depends upon orderly generation and propagation of electrical slow waves and a frequency gradient between proximal and distal pacemakers. We sought to understand how chronotropic agonists affect coupling between corpus and antrum. METHODS: Electrophysiological and imaging techniques were used to investigate regulation of gastric slow wave frequency by muscarinic agonists in mice. We also investigated the expression and role of cholinesterases in regulating slow wave frequency and motor patterns in the stomach. RESULTS: Both acetycholinesterase (Ache) and butyrylcholine esterase (Bche) are expressed in gastric muscles and AChE is localized to varicose processes of motor neurons. Inhibition of AChE in the absence of stimulation increased slow wave frequency in corpus and throughout muscle strips containing corpus and antrum. CCh caused depolarization and increased slow wave frequency. Stimulation of cholinergic neurons increased slow wave frequency but did not cause depolarization. Neostigmine (1 muM) increased slow wave frequency, but uncoupling between corpus and antrum was not detected. Motility mapping of contractile activity in gastric muscles showed similar effects of enteric nerve stimulation on the frequency and propagation of slow waves, but neostigmine (> 1 muM) caused aberrant contractile frequency and propagation and ectopic pacemaking. CONCLUSIONS: Our data show that slow wave uncoupling is difficult to assess with electrical recording from a single or double sites and suggest that efficient metabolism of ACh released from motor neurons is an extremely important regulator of slow wave frequency and propagation and gastric motility patterns.
Animals ; Cholinergic Neurons ; Cholinesterases* ; Metabolism ; Mice* ; Motor Neurons ; Muscarinic Agonists ; Muscle, Smooth ; Muscles ; Neostigmine ; Peristalsis ; Pylorus ; Stomach

We isolated mouse embryonic cardiomyocytes derived from timed-pregnant females at different periods and used patch-clamp technique to investigate the muscarinic cholinergic modulation of pacemaker current I(f) in different developmental stages. In early development stage (EDS), muscarinic agonist carbachol (CCh) significantly decreased the magnitude of the pacemaker current I(f) but had no effect in late development stage (LDS). Forskolin (a direct adenylate cyclase activator) and IBMX (a non-selective phosphodiesterase inhibitor) increased I(f) in both EDS and LDS cells. Interestingly, although both forskolin and IBMX increased basal I(f), their effects on CCh-inhibited I(f) were different. Forskolin did not reverse the inhibitory action of CCh until intermediate development stage (IDS). In contrast, IBMX reversed the inhibitory action of CCh on I(f) in EDS but not in IDS. It is suggested that a decrease in intracellular cAMP is a possible mechanism for CCh to modulate I(f). During the EDS and IDS CCh controls the cytoplasmic cAMP level by different pathways: In EDS, CCh modulates I(f) possibly by activating PDE which accelerates the breakdown of cAMP, but in IDS possibly by inhibiting adenylate cyclase (AC) which then reduces the synthesis of cAMP.
Animals ; Carbachol ; pharmacology ; Colforsin ; metabolism ; pharmacology ; Female ; Heart ; embryology ; physiology ; Mice ; Muscarinic Agonists ; pharmacology ; Myocytes, Cardiac ; drug effects ; physiology ; Pacemaker, Artificial ; Phosphodiesterase Inhibitors ; metabolism ; pharmacology ; Pregnancy ; Receptors, Muscarinic ; metabolism

In the present review article, we present an overview of beta-adrenoceptor (beta-AR) subtype expression at the mRNA and receptor protein levels in the human detrusor, the in vitro and in vivo bladder function of the beta3-AR, the in vivo effect of beta3-AR agonists on detrusor overactivity in animal models, and the available results of clinical trials of beta3-AR agonists for treating overactive bladder (OAB). There is a predominant expression of beta3-AR mRNA in human bladder, constituting 97% of total beta-AR mRNA. Also, functionally, the relaxant response of human detrusor to catecholamines is mainly mediated through the beta3-ARs. Moreover, the presence of beta1-, beta2-, and beta3-AR mRNAs in the urothelium and suburothelial layer of human bladder has been identified. Stimulation of urothelial beta-ARs results in the release of nitric oxide and an unknown substance inhibiting detrusor contractions from the urothelium. Intravenous application of CL316,243, a selective beta3-AR agonist, in rats selectively inhibits mechano-sensitive Adelta-fiber activity of the primary bladder afferents. A number of selective beta3-AR agonists are currently being evaluated in clinical trials for OAB with promising preliminary results. In conclusion, the beta3-AR agonists are the most notable alternative class of agents to antimuscarinics in the pharmacological treatment of OAB. The beta3-AR agonists act to facilitate bladder storage function probably through at least two mechanisms: first, direct inhibition of the detrusor, and second, inhibition of bladder afferent neurotransduction.
Adrenergic beta-Agonists ; Afferent Pathways ; Animals ; Catecholamines ; Contracts ; Dioxoles ; Humans ; Models, Animal ; Muscarinic Antagonists ; Nitric Oxide ; Rats ; RNA, Messenger ; Urinary Bladder ; Urinary Bladder, Overactive ; Urothelium

Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+ - dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+ - dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+ - dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+ - dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells.
Synaptotagmins/*metabolism ; Signal Transduction ; Rats ; Protein Isoforms/metabolism ; Parotid Gland/cytology/*metabolism ; Muscarinic Agonists/pharmacology ; Mice ; Exocytosis/drug effects/physiology ; Carbachol/pharmacology ; Calcium/metabolism/*physiology ; Animals ; Amylases/secretion

Animals ; Arecoline ; pharmacology ; Cholinergic Agonists ; pharmacology ; Female ; Guinea Pigs ; In Vitro Techniques ; Male ; Muscle Contraction ; drug effects ; Muscle, Smooth ; physiology ; Pyloric Antrum ; physiology ; Receptor, Muscarinic M3 ; metabolism