Too Much of a Good Thing. The vitamin A content in beef liver is very high, with 100 grams of raw liver containing over three times the recommended daily value. As a fat-soluble vitamin, vitamin A accumulates in your own liver and can cause serious health issues at high levels.
Acetylcholine is released when a nerve impulse reaches a myoneural junction. It diffuses across the synaptic cleft and binds to cholinergic receptors on the muscle fibers, causing them to contract. cholinesterase splits acetylcholine into its components, thus stopping stimulation of the muscle fibers.
Acetylcholine is released from a presynaptic neuron into the synaptic cleft. Once in the synaptic gap, acetylcholine can: - Bind to presynaptic receptors: presynaptic activation or inhibition leads to automodulation of the presynaptic cholinergic neuron.- Be degradated by acetylcholinesterase: activity of this enzime on acetylcholine triggers its degradation into choline and acetyl coenzime A, thus terminating its effect. number of drugs target acetylcholine receptors, blockade of these receptors is associated with anticholinergic (parasympatholytic) effect, while stimulation causes activation of cholinergic (parasympathomimetic) effects. This articles overviews the key concepts on the pharmacology of acetylcholine receptors, such as: