What is the corresponding term and definitions?
- Parasympathomimetic-causes stimulation of a receptor for Ach
- Parasympatholytic- blocks a receptor for Ach
- Sympathomimetic- stimulation of a receptor for norepinephrine/epinephrine
- Sympatholytic-blocks a receptor for norepinephrine/epinephrine
What are the two other terms used to refer to stimulation of receptor sites for Ach?
Muscarinic-stimulates cholinergic receptors at the parasympathetic terminal sites. Increase in airway secretions after adminstration of Ach-like drugs; there is also a decrease in blood pressure caused by slowing of the heart and vasodilation.M1-Parasympathetic ganglia,nasal submucosal glands,M2-Heart,postganglionic parasympathetic nerves,M3-Airway smooth muscle, submucosal glands,M4-postganglionic cholinergic nerves, possible effect on CNS,M5-possible effect on CNS
Nicotinic- stimulates cholinergic receptors at autonomic ganglia and at skeletal muscle sites. Increase in blood pressure resulting from stimulation of sympathetic ganglia, causing vasoconstriction when the postganglionic fibers discharge and muscle tremor caused by skeletal tissue stimulation.
How are the terms cholinergic, cholinoceptor stimulant, and cholinomimetic compared to parasympathomimetic?
They are broader terms and may include muscarinic and nicotinic receptors.
What two categories are the cholinergic, agonist divided into and name some agents?
Direct-acting agents resemble acetylcholine and stimulate cholinergic receptors directly. Acetylcholine chloride(Miochol-E), Carbachol(Carboptic), Pilocarpine hydrochloride(Pilocar,various), Methacholine(Provocholine) ,Bethanechol(Urechonline)
Indirect-acting agents inhibit the enzyme cholinesterase, to allow increased acetylcholine transmission.Echothiophate iodide (Phospholine Iodide), Pyridostigmine(Mestinon), Ambenonium(Mytelase),Neostigmine(Prostigmin), Edrophonium(Tensilon)
Why aren't all neuromuscular/ganglionic blocking agents considered anticholinergic agents?
Because the site of action is not within the parasympathetic system.
What are the effects of (antimuscarinic) parasympatholytic agents?
Bronchodilation, Preoperative drying of secretions,antidiarrheal agents,prevention of bed-wetting in children,treatment of peptic ulcer,treatment of organophosphate poisoning,treatment of (amanita muscaria) ingestion,treatment of bradycardia
What mediates the adrenergic effects?
Neurotransmitter release from sympathetic nerves and by the release of circulating catecholamines, from the adrenal medulla. In the presynaptic neuron, tyrosine is converted to dopa and then to dopamine, which is converted by dopamine B-hydroxylase to norepinephrine.
What are the location of alpha and beta adrenergic receptors and how they are distinguished?
- a1-periphereal blood vessel, postsynaptic sites (excitatory)a2-presynaptic sympathetic neurons, CNS (inhibitory)
- Alpha receptors- Generally excite, with the exception of the intestine and CNS receptors, where inhibition or relaxation occurs.
- b1-heart (excitatory)
- b2-smooth muscle(bronchial),cardiac muscle (inhibitory)
- Beta receptors- Generally inhibit or relax, with the exception of the heart, where stimulation occurs
What are some examples of adrenergic agonists and antagonists?
- Sympathomimetic- Epinephrine(Adrenalin), Ephedrine(Sudafed,various), Dextroamphetamine(Dexedrine), Dopamine(Intropin), Albuterol(Proventil,Ventolin), Salmeterol(Serevent), Ritodrine(Yutopar)
- Sympatholytic- Phentolamine(Regitine), Prazosin(Minipress), Labetalol(Normodyne, Trandate), Metoprolol(Lopressor), Propranolol(Inderal),Timolol(Betimol), Esmolol (Brevibloc)
What are the receptors in the lungs and airways for mediators released by inflammatory cells?
Histamine receptors (H1 type), Prostaglandin receptors (prostacyclin, prostaglandin D2, prostaglandin F2a, thromboxane A2) , Leukotriene receptors, Platelet-activating factors receptors, Adenosine receptors(a1,a2), Bradykinin receptors