Search results for "choline"

Can guanine-based purines be considered modulators of intestinal motility in rodents?

2010

Adenine-based purines play a pivotal role in the control of gastrointestinal motility in rodents. Recently, guanine-based purines have been also shown to exert extracellular effects in the central nervous system raising the possibility of the existence of distinct receptors for guanine-based purines. Thus, it seems likely to speculate that also guanine-based purines may play a role in the modulation of the intestinal contractility. Spontaneous and neurally-evoked mechanical activity was recorded in vitro as changes in isometric tension in circular muscle strips from mouse distal colon. Guanosine up to 3 mM or guanine up to 1 mM failed to affect the spontaneous mechanical activity, but reduc…

Activation of P2Y receptors by ATP and by its analogue, ADPbetaS, triggers two calcium signal pathways in the longitudinal muscle of mouse distal col…

2008

Our previous research showed that ATP and adenosine 5'-O-2-thiodiphosphate (ADPbetaS) induce contractile effects in the longitudinal muscle of mouse distal colon via activation of P2Y receptors which are not P2Y(1) or P2Y(12) subtypes. This study investigated the nature of the P2Y receptor subtype(s) and the mechanisms leading to the intracellular calcium concentration increase necessary to trigger muscular contraction. Motor responses of mouse colonic longitudinal muscle to P2Y receptor agonists were examined in vitro as changes in isometric tension. ATP or ADPbetaS induced muscular contraction, which was not affected by P2Y(11) or P2Y(13) selective antagonists. Calcium-free solution or th…

Synthesis and Muscarinic Activity of Isoxazole-substituted 1,2,5,6-Tetrahydropyridines

1994

Affinity and efficacy of racemic, (+)-, and (−)-methacholine in muscarinic inhibition of [3H]-noradrenaline release

1985

The right postganglionic sympathetic nerves of rat isolated perfused hearts (previously loaded with [3H]-noradrenaline) were stimulated electrically with 10 trains of 10 pulses at 10 Hz. The inhibition by methacholine of stimulation-evoked [3H]-noradrenaline overflow into the perfusate (determined in the presence of corticosterone, desipramine, phentolamine, and propranolol) was taken as a measure for activation of presynaptic muscarinic receptors. The evoked [3H]-noradrenaline overflow was inhibited by (+)-, racemic, and (-)-methacholine in a reversible and concentration-dependent manner. The concentration causing 50% inhibition (IC50) was 0.1, 0.26, and 65 microM, respectively, resulting …

Effects of treatments for drooling on caries risk in children and adolescents with cerebral palsy

2019

Background Neuromuscular impairment makes individuals with cerebral palsy (CP) more prone to drooling. Among the treatment options, there are procedures that interfere with saliva production. It is imperative to evaluate the effect of the different modalities since the reduction in salivary flow rate/production may exacerbate the risk of dental caries. Material and Methods The aim of this study was to compare the effects of different treatments for drooling on caries risk and salivary parameters in children and adolescents with CP. Study design A total of 142 children and adolescents with CP, aged 6 to 18 years, were assigned to groups based on the different treatments they had received for…

Cholinergic Control of Synchronized Seminal Emissions in Drosophila

2004

0960-9822 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; In many animal species, copulation involves the coordinated release of both sperm and seminal fluid, including substances that change female fertility and postmating behavior. In Drosophila melanogaster, these substances increase female fertility and prevent mating with a second male. By using a PGal4 strain, we targeted together with other cells a dozen cholinergic neurons found only in the male abdominal ganglion (Abg-MAch). Genetic feminization apparently deleted these neurons in males and significantly increased their copulation duration, blocked their fertility in 60% of cases, and only weakly repress…

Expression of α4-1 and α5 Nicotinic Cholinoceptor mRNA in the Aging Rat Cerebral Cortex

1997

Although important in neurodegeneration, systematic studies of nicotinic acetylcholine receptor expression in normal aging human brains are difficult to perform. We have studied the expression of nicotinic receptor alpha 4-1 and alpha 5 mRNA in the frontal and parietal isocortex of 3- (young adult), 24- (late middle aged), and 33-month-old (old) rats by nonisotopic in situ hybridization. In all groups transcripts were mainly present in layer II/III and V pyramidal neurons. The numerical densities of alpha 4-1 mRNA-containing neurons with respect to those of cresyl violet-stained neurons decreased with aging in the rat frontal and parietal cortex, while those of alpha 5 mRNA-containing neuro…

Neurotransmitter receptor density changes in Pitx3ak mice – A model relevant to Parkinson’s disease

2014

Abstract Parkinson’s disease (PD) is the second most common neurodegenerative disorder, characterized by alterations of nigrostriatal dopaminergic neurotransmission. Compared to the wealth of data on the impairment of the dopamine system, relatively limited evidence is available concerning the role of major non-dopaminergic neurotransmitter systems in PD. Therefore, we comprehensively investigated the density and distribution of neurotransmitter receptors for glutamate, GABA, acetylcholine, adrenaline, serotonin, dopamine and adenosine in brains of homozygous aphakia mice being characterized by mutations affecting the Pitx3 gene. This genetic model exhibits crucial hallmarks of PD on the ne…

Behavioral deficits induced by lead exposure are accompanied by serotonergic and cholinergic alterations in the prefrontal cortex

2013

The effects of long-term lead (Pb) exposure producing a blood Pb concentration of lower than 20 μg/dL, i.e. below that associated with overt neurological deficits in occupationally exposed individuals, was studied in adult rats. In order to assess gender differences, we performed parallel behavioral experiments in male and female rats. Exposure to Pb acetate (50 ppm in drinking water) for 6 months induced motor and cognitive alterations, however these effects were gender- and task-dependent. Chronic lead exposure impaired spatial learning assessed in the Morris water maze test (MWM) in both genders, whereas it only induced hyperactivity in the open field and impaired motor coordination in t…

Effects of 5-HT4 receptor stimulation on basal and electrically evoked release of acetylcholine from guinea-pig myenteric plexus

1992

The effects of 5-methoxytryptamine and 5-hydroxytryptamine (5-HT) on both basal and electrically evoked outflow of tritium were studied in guinea-pig myenteric plexus preparations preincubated with [3H]-choline. Basal outflow. 5-Methoxytryptamine caused a transient and calcium-dependent increase in basal outflow of [3H]acetylcholine that was abolished by tetrodotoxin. Ondansetron (1 μmol/1) did not affect the stimulatory response of 5-methoxytryptamine but ICS 205-930 (1 and 3 μmol/1) produced parallel rightward displacements of the concentration-response curve to 5-methoxytryptamine. The PKB value for ICS 205-930 was 6.6 suggesting an involvement of 5-HT4 receptors. 5-HT caused an increase…