Acetylcholine effects

Although some steroids have been reported to reduce the toxic effects of some insecticides, the steroid ethylestrenol decreased the rate of recovery of depressed cholinesterase activity in disulfoton- pretreated rats (Robinson et al. 1978). The exact mechanism of this interaction was not determined. Ethylestrenol alone caused a small decrease in cholinesterase activity, and, therefore, resulted in an additive effect. Rats excreted less adrenaline and more noradrenaline when given simultaneous treatments of atropine and disulfoton compared with rats given disulfoton alone (Brzezinski 1973). The mechanism of action of disulfoton on catecholamine levels may depend on acetylcholine accumulation. In the presence of atropine, the acetylcholine effect on these receptors increases the ability of atropine to liberate catecholamines. 

Acetylcholine is involved in many aspects of the regulation of the cardiovascular system. Thus, it may also play a role in the control of intercellular communication. Very early in gap junction research the effect of acetylcholine as an important transmitter on gap junction conductance has been investigated. First, Petersen and Ueda [1976] demonstrated an increase in junctional resistance in pancreatic acinar cells following the application of acetylcholine. Concomitantly, the release of amylase was stimulated. A minimum concentration of 1 pmol/l acetycholine was required to evoke uncoupling. The next question was, how is the acetylcholine effect mediated Calcium has been considered to contribute to the mechanism of action [Iwatsuki and Pertersen,... 

Nicotine and the neurotransmitter acetylcholine, which acts on maintenance neurons, have similar structures, as Figure 14.28 illustrates. Nicotine molecules are therefore able to bind to acetylcholine receptor sites and trigger many of acetylcholines effects, including relaxation and increased digestion, which... 

Certain G-proteins can induce opening of channel proteins. In this way, potassium channels can be activated (e. g., acetylcholine effect on sinus node, p.104 opioid effect on neural impulse transmission, p.208). 

Recent investigations have focused on OP nerve agent poisoning secondary to acetylcholine effects. 

Because physostigmine acts on the enzyme cholinesterase— which is present at all cholinergic synapses—this drug increases acetylcholine effects at the nicotinic junctions as well as muscarinic ones. Bethanechol, on the other hand, is a direct-acting agent that is selective for muscarinic receptors and has no effect on nicotinic junctions such as the skeletal muscle end plate. The answer is (B). 

This neurotoxin blocks the release of the chemical messenger acetylcholine, effectively causing chemical denervation. The injections reduce facial lines caused by hyperfunctional muscles. 

Turning from brain slices to subcellular fractions, the acetylcholine effect was localised in the synaptosomal fraction by Durell Sodd (1966). Synthesis of phosphatidic acid from [32p]ATP was sensitive to acetylcholine, but not synthesis from [ 2p] glycerophosphate. This indicated that reaction 2 rather than reaction 1 was involved (Hokin Hokin, 1959). Confirmation comes from the finding that diacylglycerol kinase is about ten times as... 

Absolute Accuracy of Measurement, 13-20 Accuracy of K Microelectrode, 77-85 Acetazolamide, 95-98, 100 Acetylcholine Effects, 58, 61 Acidification, Renal Tubular, 89 Antimony Microelectrodes, 43, 89 Aplysia Neurons, 57 Artificial Beta Cell, 189 Artificial Pancreas, 189... 

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