Download Chapter VII anti-cholinesterase drugs and cholinesterase drugs

Chapter VII
anti-cholinesterase drugs and cholinesterase drugs
Section 1 : Today we learn is anti-cholinesterase drugs.
Section 2 : In vivo cholinesterase divided into two , in general
acetylcholinesterase is dominant. Mainly in the synaptic cleft cholinergic
nerve endings .
Section 3 : Now mentions cholinesterase (cholinesterase), take a look at
it . It is a glycoprotein with a relatively high specific one enzyme
molecule can be hydrolyzed in a minute 6 * 105 molecules of
acetylcholine (ACH). The whole process can be understood by this
animation , the two combine to form complexes , complexes and
acetylated cleavage of choline esterase , acetyl cholinesterase rapid
hydrolysis , separation of acetic acid , (acetylcholinesterase, AchE)
activity recovery.
Section 4 : acetylcholine (acetylcholine, Ach) excited M, N receptors,
such as the eyes, skeletal neuromuscular junction , gastrointestinal tract
and other produce pharmacological effects.
Section 5 : anti- cholinesterase drugs (anticholinesterase agents) and
acetylcholine similar to it and (acetylcholinesterase, AchE) combination
makes AchE activity was inhibited , resulting in cholinergic nerve
endings release acetylcholine (acetylcholine, Ach) can not be timely
hydrolysis to produce cholinergic effects . Anti-cholinesterase drugs are
divided into two categories, one is easily reversible anticholinesterase
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drugs, such as neostigmine (neostigmine); another embarrassing
reversible anticholinesterase drugs, such as organophosphates class
(organophosphate).
Section 6 : Today, we focus to learn neostigmine and some other easily
reversible anticholinesterase drugs. Neostigmine can produce M, N -like
effects . Low oral absorption , rarely through blood-brain barrier (BBB),
so there is no obvious central role , not easily through the cornea, the eye
effect is also weak . But neostigmine effect on skeletal muscle is the
strongest. Why ? Are the following reasons .
Link Section 32 : by inhibiting AchE activity , increasing concentrations
of excitatory synaptic cleft Ach M, N cholinergic receptors ; directly
excited N2 skeletal muscle motor end plate receptors ; promotion
campaigns nerve endings release Ach. To sum up three reasons,
neostigmine effect on skeletal muscle is the strongest.
Link back to the section six : neostigmine on the gastrointestinal tract and
bladder smooth muscle stimulant is also strong, but glands , eye ,
cardiovascular and bronchial smooth muscle stimulant weak.
Section 7 : According to its pharmacological effects , mainly used in
clinical myasthenia gravis . What is myasthenia gravis (myasthenia
gravis)?
Link to section 33 : myasthenia gravis is an autoimmune disease because
the body produces Ach receptor antibodies , making a significant
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reduction in the number of receptors . Patients showed muscle fatigue.
Neostigmine treatment of myasthenia gravis through intramuscular
injection , after about 15 minutes can make the symptoms , maintaining
2-4 hours.
Link back to the section seven : Also used after surgery bloating gas and
urinary retention, gastrointestinal smooth muscle through excitement and
detrusor promote venting and urination ; addition, neostigmine also be
used for paroxysmal supraventricular tachycardia and competitive
neuromuscular blocking drug overdose rescue .
Section 8 : neostigmine adverse reactions were overly excited about
cholinergic receptors .
Link 34 : In the treatment of myasthenia gravis (myasthenia gravis)
overdose may produce sweating , incontinence , bradycardia, muscle
tremors , muscle weakness and so on.
Section 9 : physostigmine (Physostigmine) fat-soluble high , oral can
absorb easily through the blood-brain barrier , a small dose of excitement
in the center, large doses inhibited . Drops easily through the cornea, the
eye role and pilocarpine similar , to reduce the pupil to reduce intraocular
pressure , ciliary muscle contraction caused by spasm . So mainly used in
clinical glaucoma.
Section 10 : physostigmine and neostigmine are anti-cholinesterase drugs,
they have some similarities and differences what ? Similarities: Both
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mechanisms , are cholinesterase-inhibiting activity, increase the
concentration of excited Ach M, N receptor ; differences: physostigmine
oral, injectable are more easily absorbed ; And through the blood brain
barrier , resulting in the central role ;
Section 11 : physostigmine and pilocarpine are clinically to treat
glaucoma . Their similarities and differences in what they do ?
Similarities : both for the parts of eyes; the same usage
Differences: different mechanisms - pilocarpine eye directly on the M
receptor excitement , narrowing the pupil to reduce intraocular pressure ,
spasm ; while physostigmine by inhibiting cholinesterase activity ,
increasing the concentration of excited M Ach receptors , resulting in the
role of the eye . Pilocarpine is a direct effect of the indirect effects of
physostigmine . In addition, physostigmine easily through the cornea ,
and so the role than pilocarpine fast , strong , long , but irritating is also
large.
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