Search results for "Neurotransmitter"

Prostanoid receptors of the EP3 subtype mediate inhibition of evoked [3 H]acetylcholine release from isolated human bronchi

1998

1 The release of neuronal [3H]acetylcholine (ACh) from isolated human bronchi after labelling with [3H]choline was measured to investigate the effects of prostanoids. 2 A first period of electrical field stimulation (S1) caused a [3H]ACh release of 320±70 and 200±40 Becquerel (Bq) g−1 in epithelium-denuded and epithelium-containing bronchi respectively (P>0.05). Subsequent periods of electrical stimulation (Sn, n=2, 3, and 4) released less [3H]ACh, i.e. decreasing Sn/S1 values were obtained (0.76±0.09, 0.68±0.07 and 0.40±0.04, respectively). 3 Cumulative concentrations (1–1000 nM) of EP-receptor agonists like prostaglandin E2, nocloprost, and sulprostone (EP1 and EP3 selective) inhibited ev…

Acupuncture: its neurophysiological basis: an anaesthetist's foreword.

1978

Intestinal transport in constipation and diarrhoea.

1988

Approximatively 10 liters of fluid enter the gastrointestinal tract with food and endogenous secretions, and only less than 100 ml or 1% leave it with the faeces. Minor changes of this equilibrium in the intestinal transport may cause diarrhoea or constipation. Functions of small and large intestine differ markedly in transport of electrolytes and water. The relatively leaky epithelium of the small intestine allows for rapid equilibrium of osmolality in both directions while the tight epithelium of the colon preserves electrolytes and water once they have been absorbed. It may compensate secretory diarrhoea of the small intestine for instance caused by bacterial toxins to a certain degree u…

NO as a signalling molecule in the nervous system

2002

The discovery that nitric oxide (NO) functions as a signalling molecule in the nervous system has radically changed the concept of neural communication. Indeed, the adoption of the term nitrergic for nerves whose transmitter function depends on the release of NO or for transmission mechanisms brought about by NO (Moncada et al., 1997) emphasizes the specific characteristics of this mediator. The physical properties of NO prevent its storage in lipid-lined vesicles and metabolism by hydrolytic degradatory enzymes. Therefore, unlike established neurotransmitters, NO is synthesized on demand and is neither stored in synaptic vesicles nor released by exocytosis, but simply diffuses from nerve t…

Neurotransmitters involved in the habenular control of raphe-hippocampal circuit

1989

Psychotropic drug competition for [3H]imipramine binding further indicates the presence of only one high-affinity drug binding site on human α1-acid …

1983

In vivo release of non-neuronal acetylcholine from the human skin as measured by dermal microdialysis: effect of botulinum toxin

2006

1.--Acetylcholine is synthesized in the majority of non-neuronal cells, for example in human skin. In the present experiments, the in vivo release of acetylcholine was measured by dermal microdialysis. 2.--Two microdialysis membranes were inserted intradermally at the medial shank of volunteers. Physiological saline containing 1 muM neostigmine was perfused at a constant rate of 4 microl min(-1) and the effluent was collected in six subsequent 20 min periods. Acetylcholine was measured by high-pressure liquid chromatography (HPLC) combined with bioreactors and electrochemical detection. 3.--Analysis of the effluent by HPLC showed an acetylcholine peak that disappeared, when the analytical c…

NANC inhibitory neurotransmission in mouse isolated stomach: involvement of nitric oxide, ATP and vasoactive intestinal polypeptide

2003

1. The neurotransmitters involved in NANC relaxation and their possible interactions were investigated in mouse isolated stomach, recording the motor responses as changes of endoluminal pressure from whole organ. 2. Field stimulation produced tetrodotoxin-sensitive, frequency-dependent, biphasic responses: rapid transient relaxation followed by a delayed inhibitory component. 3. The inhibitor of the synthesis of nitric oxide (NO), l-NAME, abolished the rapid relaxation and significantly reduced the slow relaxation. Apamin, blocker of Ca2+-dependent K+ channels, or ADPbetaS, which desensitises P2y purinoceptors, reduced the slow relaxation to 2-8 Hz, without affecting that to 16-32 Hz or the…

Serotonin transporter gene polymorphism (5-HTTLPR) and emotional response to auditory hallucinations in schizophrenia

2005

The serotonin transporter (5-HTT) has a crucial function in the regulation of serotonin (5-HT) reuptake in presynaptic neurons. 5-HT is a major modulator of emotional behaviour and circadian rhythms. In addition to its neurotransmitter role, it is also an important regulator of morphogenetic activities during early brain development as well as during adult neurogenesis and plasticity (Murphy et al., 2001).

Association study of affective disorders with genetic polymorphisms of monoamine oxidases

2000

Introduction: Monoamine oxidases (MAO) catalyze the oxidative deamination of monoamines like norepinephrine, serotonin and dopamine. The existing MAOs (A and B) have distinct although partially overlapping biological functions and distributions in the brain. MAO A is mainly expressed in catecholaminergic neurons. Thirty-fold differences in enzyme activity of MAO A can be found in cultured cells from different individuals suggesting a genetic determination of enzyme activity. Indeed, a point mutation in the coding region of the gene which creates a restriction site for Fnu4HI alters the activity. Moreover, the pharmacological inhibition of monoamine oxidase A activity is one of the most effe…