Description : The most efficacious inhibitor of catecholamine synthesis in the body is: A. α-methyl-p-tyrosine B. α-methyldopa C. α-methyl-norepinephrine D. Entacapone
Last Answer : A. α-methyl-p-tyrosine
Description : Following events occur in the cytoplasm and not inside storage vesicles, except (a) Conversion of tyrosine to dopa (b) Conversion of dopa to dopamine (c) Conversion of dopamine to norepinephrine (d) Conversion of dopamine to 3,4 dihydroxy phenyl acetic acid
Last Answer : Ans: C
Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase
Last Answer : Answer : B
Description : Choose the correct statement from the following about a1 – adrenergic receptor agonists (a) Norepinephrine > isoproterenol > epinephrine (b) Norepinephrine < epinephrine > isoproterenol (c) Epinephrine = norepinephrine >> isoproterenol (d) Epinephrine > isoproterenol > norepinephrine
Description : Select the correct statement from the following about a1 – adrenergic receptor agonists (a) Isoproterenol > epinephrine = norepinephrine (b) Epinephrine > isoproterenol > norepinephrine (c) Isoproterenol = epinephrine = norepinephrine (d) Epinephrine = norepinephrine > isoproterenol
Last Answer : Ans: A
Description : Action of norepinephrine and epinephrine are terminated by (a) Reuptake into nerve terminal (b) Dilution by diffusion and uptake at extraneuronal site (c) Metabolic transformation (d) All of the above
Last Answer : Ans: D
Description : Which of the following drugs is the drug of choice in anaphylaxis associated with bronchospasm and hypotension ? (a) Cortisone (b) Epinephrine (c) Isoproterenol (d) Norepinephrine (e) Phenylephrine
Last Answer : Ans: B
Description : In male sex organs _______ system is responsible for erection. (a) Sympathetic (b) Parasympathetic (c) Norepinephrine (d) None of the above
Description : The neurotransmitter agent that is normally released in the sinoatrial node of the heart in response to a blood pressure increase is (a) Acetylcholine (b) Dopamine (c) Epinephrine (d) Glutamate (e) Norepinephrine
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : Tyrosine is required for the synthesis of all of the following except (A) Melatonin (B) Epinephrine (C) Norepinephrine (D) Thyroxine 222 MCQs IN BIOCHEMISTRY
Last Answer : Answer : A
Description : Which of the following anticholinergic drugs is primarily used in preanaesthetic medication and during surgery (a) Glycopyrrolate (b) Pipenzolate methyl bromide (c) Isopropamide (d) Dicyclomine
Description : Phenylephrine (a) Mimics the transmitter at post-synaptic receptors (b) Displaces transmitter from axonal terminal (c) Inhibits synthesis of transmitter (d) None of the above
Description : Guanethidine inhibits (a) Synthesis of transmitter (b) Metabolism of transmitter (c) Release of transmitter (d) Displacement of transmitter from axonal terminal
Description : Typical results of beta-receptor activation include which one of the following? (a) Hypoglycemia (b) Lipolysis (c) Glycogen synthesis (d) Decreased skeletal muscle tremor (e) Decreased rennin secretion
Description : Following enzyme is involved in the synthesis of actylcholine (a) Choline acetyl transferase (b) Acetyl cholinesterase (c) Both (a) and (b) (d) None of the above
Description : The biochemical mechanism of action of digitalis is associated with (a) A decrease in calcium uptake by the sarcoplasmic reticulum (b) An increase in ATP synthesis (c) A modification of the actin molecule (d) An increase in systolic intracellular calcium levels (e) A block of sodium/calcium exchange
Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
Last Answer : Answer : C
Description : The rate limiting enzyme in the synthesis of catecholamines is: A. Tyrosine hydroxylase B. Dopa decarboxylase C. Dopamine β-hydroxylase D. Noradrenaline N-methyl transferase
Last Answer : A. Tyrosine hydroxylase
Description : Choose the most potent and most efficacious LDLcholesterol lowering HMG-CoA reductase inhibitor: A. Lovastatin B. Simvastatin C. Pravastatin D. Atorvastatin
Last Answer : D. Atorvastatin
Description : Which of the following is an efficacious antiinflammatory drug but a relatively weak inhibitor of cyclooxygenase: A. Nimesulide B. Paracetamol C. Ketoprofen D. Indomethacin
Last Answer : A. Nimesulide
Description : Methyldopa lowers BP by: A. Inhibiting dopa decarboxylase in adrenergic nerve endings B. Generating α-methyl noradrenaline in brain which reduces sympathetic tone C. Generating α-methyl ... as a false transmitter in peripheral adrenergic nerve endings D. Activating vascular dopamine receptors
Last Answer : B. Generating α-methyl noradrenaline in brain which reduces sympathetic tone
Description : Propranolol does not block the following action of adrenaline (a) Bronchodilation (b) Lipolysis (c) Muscle tremor (d) Mydriasis
Description : Propanolol can be used to allay anxiety associated with (a) Chronic neurotic disorer (b) Schizopherenia (c) Short-term stressful situation (d) Endogenous depression
Description : The ß-adrenergic blocker which possesses both ß1 selectivity as well as intrinsic sympathomimetic activity is (a) Alprenolol (b) Atenolol (c) Acebutolol (d) Metoprolol
Description : Which of the following is true of sildenafil (a) It enhances sexul enjoyment in normal men (b) It delays ejaculation (c) It is indicated only for treatment of erectile dysfunction in men (d) It blocks cavernosal a2 adrenoceptors
Description : Prazosin is an effective antihypertensive while nonselective a adrenergic blockers are not because (a) It is the only orally active a blocker (b) It improves plasma lipid profile (c) It does not concurrently enhance noradrenaline release (d) It improves urine flow in males with prostatic hypertrophy
Description : The drug which produces vasoconstriction despite being an a adrenergic blocker is (a) Phenoxybenzamine (b) Ergotamine (c) Dihydroergotoxine (d) Tolazoline
Description : Vasoconstrictors should not be used in (a) Neurogenic shock (b) Haemorrhagic shock (c) Secondary shock (d) Hypotension due to spinal anaesthesia
Description : While undergoing a surgical procedure a patient develops hypotension. Which of the following drugs can be injected intramuscularly to raise his BP (a) Noradrenaline (b) Isoprenaline (c) Mephentermine (d) Isoxsuprine
Description : Continuous exposure of ctecholaminesensitive cells and tissues to adrenergic agonists causes a progressive diminition in their capacity to respond, this phenomenon is called as (a) Refractoriness (b) Desensitization (c) Tachyphylaxis (d) All of the above
Description : Ephedrine is similar to adrenaline in the following feature (a) Potency (b) Inability to penetrate blood-brain barrier (c) Duration of action (d) Producing both a and ß adrenergic effects
Description : Dobutamine differs from dopamine in that (a) It does not activate peripheral dopaminergic receptors (b) It does not activate adrenergic ß receptors (c) It causes pronounced tachycardia (d) It has good blood-brain barrier penetrability
Description : Noradrenaline is administered by (a) Subcutaneous injection (b) Intramuscular injection (c) Slow intravenous infusion (d) All of the above routes
Description : Adrenaline raises blood glucose level by the following actions except (a) Inducing hepatic glycogenolysis (b) Inhibiting insulin secretion from pancreatic ß cells (c) Augmenting glucagons secretion from pancreatic a cells (d) Inhibiting peripheral glucose utilization
Description : a2–adrenergic receptors are associated with following except (a) Increase in phospholipase C activity (b) Increase in potassium channel conductance (c) Decrease in calcium channel conductance (d) Increase in adenylyl cyclase activity
Description : Low doses of adrenaline dilate the following vascular bed (a) Cutaneous (b) Mucosal (c) Renal (d) Skeletal muscle
Description : A sympathomimetic amine that acts almost exclusively by releasing noradrenaline from the nerve endings is (a) Ephedrine (b) Dopamine (c) Isoprenaline (d) Tyramine
Description : Tyramine induces release of noradrenaline from adrenergic nerve endings (a) By depolarizing the axonal membrane (b) By mobilizing Ca2+ (c) By a nonexocytotic process (d) Only in the presence of MAO inhibitors
Description : Atropine is contraindicated in (a) Cyclic AMP (b) Inositol trisphosphate (c) Diacyl glycerols (d) G protein
Description : The most effective antidote for belladonna poisoning is (a) Neostigmine (b) Physostigmine (c) Pilocarpine (d) Methacholine
Description : The most suitable mydratic for a patient of corneal ulcer is (a) Atropine sulfate (b) Homatropine (c) Cyclopentolate (d) Tropicamide
Description : Which of the following mydriatics has the fastest and briefest action ? (a) Atropine (b) Homatropine (c) Tropicamide (d) Cyclopentolate
Description : Glycopyrrolate is the preferred antimuscannic drug for use before and during surgery because (a) It is potent and fast acting (b) It has no central action (c) It has antisecretory and vagolytic actions (d) All of the above
Description : Hyoscine differs from atropine in that it (a) Exerts depressant effects on the CNS at relatively low doses (b) Exerts more potent effects on the heart than on the eye (c) Is longer acting (d) Has weaker antimotion sickness activity
Description : a1 – receptors are coupled with _______ G protein. (a) Gs (b) Gi (c) Gq (d) Go
Description : Atropine does not exert relaxant/ antispasmodic effect on the following muscle (a) Intestinal (b) Ureteric (c) Bronchial (d) Layngeal
Description : The cardiac muscarinic receptors (a) Are of the M1 subtype (b) Are of the M2 subtype (c) Are selectively blocked by pirenzepine (d) Function through the PIP2 ? IP3/DAG pathway