Cholinergic Definition and Its Effects
Cholinergic is the term used for referring to molecule acetylcholine. So, what does cholinergic mean? It’s generally used to define neurons, synapses or receptors that make use of acetylcholine. For example, cholinergic neuron is the neuron that can release acetylcholine, and cholinergic receptor is the receptor where acetylcholine binds. And acetylcholine is the signal molecule in nervous system, which is used by the nerve cells for transferring the information. It’s present widely in peripheral nervous system that is actually involved in contracting smooth muscle and dilating blood vessels, with other functions. Acetylcholine actually plays very important role at neuromuscular junction that is at joint between the nerve cells and the muscle.
Acetylcholine involvement in the diseases of nervous system has made this cholinergic system the main target for the therapeutic purposes. The drugs that will activate (agonists) and inactivate (antagonists) receptors, and drugs that modulate the cholinergic activity just by facilitating and preventing the formation, release and degradation of acetylcholine, is developed with an aim to treat many neuropsychiatric conditions. Nonetheless, anticholinergics—the drug that decrease and block effects of acetylcholine—can be widely used for treating many conditions. Some are the involuntary movements, incontinence, gastrointestinal disorders, and Parkinson’s disease. One more compound that can block release of the acetylcholine is the botulinum toxin—agent made by the type of bacterium that paralyzes skeletal muscle so organism cannot move and will also cause death.
Effects of cholinergic receptors will include the muscle contraction, constriction of iris (miosis), heart rate deceleration, and of lens, broncho-constriction and mucus secretion. Conversely, effects of the inactivating cholinergic receptors will include heart rate acceleration, muscle relaxation, lens flattening (cyclopegia) and pupil dilation (mydriasis), dryness of upper airway (of respiratory system), the inhibition of tear formation, mouth dryness, urine retention, mucociliary activity slow down in respiratory tract, muscle relaxation and constipation.
Cholinergic Side Effects
The cholinergic drugs will help to treat certain disorders as well as ameliorate symptoms however they have some negative effects. Most of the cholinergic drugs are the anticholinergics that are they reduce and block effects of the acetylcholine. For example, acetylcholine antagonist’s hexamethonium & trimethaphan, used for treating the high blood pressure, will produce paralysis of autonomic nervous system, and producing effects like blurred vision or inability to urinate. Generally anticholinergics will cause an increase in the body temperature just because they decrease an amount of sweating; and they will induce hallucinations, drowsiness, and dry mouth, and confusion, difficulty in urinating, constipation, and memory deficits. Among older people, they will cause confusion, cognitive dysfunction and memory loss. Mixing anticholinergics with the alcohol have same side effects like overdosing with the anticholinergics that include fever, dizziness, accelerated heart rate, confusion, trouble in breathing, unconsciousness, hallucinations, and death.