Cholinergic receptors definition

A more definite way to solve the issue was the use of affinity labeling for the cholinergic receptor. This method is based on the use of N-maleimido benzyl (or phenyl) trimethylammonium (i.e. MBTA or MPTA) which binds to the anionic site of the receptor and makes a covalent link with a reduced S-S group in its vicinity (Karlin and Cowburn, 1973). With this method and SDS gel electrophoresis... 

In the mouse, whereas no evidence of H3 receptors was found in isolated gastric glands (Muller et al., 1993), in the whole stomach, (R)a-methylhistamine actually increased, and thioperamide decreased acid secretion, thus indicating a definite stimulatory role for H3 receptors in this species (Table 2). Apparently, this excitatory effect, which contrasts with the observations obtained in other models, was due to an inhibitory effect on somatostatin release from fundic D cells (Schubert et al., 1993 Vuyyuru and Schubert 1993). Also, an inhibitory effect on somatostatin secretion mediated by H3 agonists was observed in other species (rat and dog). However, contrarily to what might have been expected, in these species, the inhibitory effect on somatostatin is not followed by an increase in acid secretion, but it is instead followed by a decrease, owing to the predominant H3-mediated inhibition on the release of excitatory mediators (histamine, acetylcholine) from other sites (ECL, cholinergic nerve terminals)... 

IMS in OP-poisoned patients appears 24-96 h after an apparently well-treated acute cholinergic crisis phase. By definition, OP-poisoned patients should completely recover from the cholinergic crisis and then develop a syndrome. Clinically, IMS is characterized by acute paralysis and weakness in the territories of several cranial motor nerves, neck flexors, facial, extraocular, palatal, nuchal, proximal limb, and respiratory muscles 24-96 h after poisoning. Generalized weakness, depressed deep tendon reflexes, ptosis (drooping of the upper eyelids due to paralysis of the third cranial nerve), and diplopia (double vision of an object) are also evident. These symptoms may last for several days or weeks depending on the OP involved. Despite severe AChE inhibition, muscle fasciculations and muscarinic receptor-associated hypersecretory activities are absent. 

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