Description : All of the following subserve as intracellular second messengers in receptor mediated signal transduction except: A. Cyclic AMP B. Inositol trisphosphate C. Diacyl glycerols D. G proteins
Last Answer : D. G proteins
Description : Atropine is contraindicated in (a) Cyclic AMP (b) Inositol trisphosphate (c) Diacyl glycerols (d) G protein
Last Answer : Ans: D
Description : The best understood intracellular messenger is cyclic AMP (cAMP). Which of the following statement(s) concerning this intracellular messenger is/are correct? a. Intracellular cyclic AMP is constantly ... of adenylate cyclase d. cAMP is the only cyclic nucleotide active as an intracellular messenger
Last Answer : Answer: a, b The prototypic intracellular messenger is cAMP. To function as a mediator, the concentration of cAMP must change rapidly. In resting cells, cAMP is continuously being degraded by ... produce cGMP. Intracellular calcium ions also serve as second messengers in a large number of cells
Description : The following serotonergic receptor functions primarily as an autoreceptor on neurones: A. 5-HT1A B. 5-HT2A C. 5-HT3 D. 5-HT4
Last Answer : A. 5-HT1A
Description : The most important mechanism by which tetracycline antibiotics exert antiimicrobial action is (a) They chelate Ca2+ ions and alter permeability of bacterial cell membrane (b) They bind to 30S ribosomes ... peptide chain in the bacteria (d) They interfere with DNA mediated RNA synthesis in bacteria
Last Answer : Ans: B
Description : The most important mechanism by which tetracycline antibiotics exert antimicrobial action is: A. They chelate Ca2+ ions and alter permeability of bacterial cell membrane B. They bind to 30S ribosomes ... peptide chain in the bacteria D. They interfere with DNA mediated RNA synthesis in bacteria
Last Answer : B. They bind to 30S ribosomes and inhibit bacterial protein synthesis
Description : Eicosanoids mediate inflammation in a variety of ways. Of the following statements, which are true with regard to this? a. Eicosanoids are stored in cytoplasmic granules ... include vasodilatation, vasoconstriction, increased vascular permeability and both chemotaxis and chemoattractant inhibition
Last Answer : Answer: b, d The eicosanoids are derived from arachidonic acid (eicosatetraenoic acid) and consist of prostaglandins, thromboxanes, leukotrienes and lipoxins. The eicosanoids are not ... nervous system d. Mononuclear phagocytes release a variety of proinflammatory cytokines and growth factors
Description : The action of histamine that is not mediated through H1 receptors is: A. Release of EDRF from vascular endothelium resulting in vasodilatation B. Direct action on vascular smooth muscle causing vasodilatation C. Bronchoconstriction D. Release of catecholamines from adrenal medulla
Last Answer : B. Direct action on vascular smooth muscle causing vasodilatation
Description : Olanzapine has the following features except: A. It is an antipsychotic drug with weak D2 receptor blocking action B. It has potent 5-HT2 blocking and antimuscarinic actions C. It lowers seizure threshold D. It produces prominent extrapyramidal side effects
Last Answer : D. It produces prominent extrapyramidal side effect
Description : Intermediate in the denovo synthesis of triacyl glycerols include all the following except (A) Fatty acyl CoA (B) CDP diacyl glycerol (C) Glycerol-3-phosphate (D) Lysophosphatidic acid
Last Answer : Answer : B
Description : Current concepts concerning the intestinal absorption of triacylglycerols are that (A) They must be completely hydrolysed before the constituent fatty acids can be absorbed (B) They are hydrolysed partially ... portal blood (D) In the absence of bile the hydrolysis of triacyl glycerols is absorbed
Description : The following is a selective 5-HT1D receptor agonist: A. Buspirone B. Ondansetron C. Sumatriptan D. α-methyl 5-HT
Last Answer : C. Sumatriptan
Description : Which of the following is a selective H1 receptor agonist: A. 4-methyl histamine B. Impromidine C. 2-Thiazolyl ethylamine D. Chlorpheniramine
Last Answer : C. 2-Thiazolyl ethylamine
Description : Consider the following statements: 1. When a nerve fibre is stimulated, a profound change is produced in the electrical properties of surface membrane and in steady potential. 2. Upon excitation, the resting potentialis suddenly changed. 3. It is due ... 1, 2, 3 (b) 2, 3 (c) 1, 2, 3, 4 (d) 1, 2, 4
Last Answer : Ans:(d)
Description : Actions of prostaglandin E2 include the following except: A. Fall in blood pressure B. Bronchoconstriction C. Uterine contraction D. Inhibition of gastric acid secretion
Last Answer : B. Bronchoconstriction
Description : Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the ... through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors
Last Answer : Answer: a, c All water-soluble regulatory molecules bind to the cell surface receptor proteins. Binding of the appropriate ligand evokes an intracellular signal which usually regulates ... are adenylate cyclase, which converts ATP to cAMP, and the polyphosphoinositide-specific phospholipase C
Description : Protein kinase C is activated by (A) Cyclic AMP (B) Cyclic GMP (C) Diacyl glycerol (D) Inositol triphosphate
Last Answer : Answer : C
Description : While prescribing a first generation H1 antihistaminic the patient should be advised to avoid: A. Driving motor vehicles B. Consuming processed cheese C. Strenuous physical exertion D. All of the above
Last Answer : A. Driving motor vehicles
Description : Autacoids differ from hormones in that: A. Autacoids are involved only in the causation of pathological states B. Autacoids do not have a specific cell/tissue of origin C. Autacoids generally act locally at the site of generation and release D. Both ‘B’ and ‘C’ are correct
Last Answer : D. Both ‘B’ and ‘C’ are correct
Description : Which of the following regulates lipolysis in adipocytes? (A) Activation of fatty acid synthesis mediated by CAMP (B) Glycerol phosphorylation to prevent futile esterification of fatty acids (C) ... result of hormone stimulated increases in CAMP levels (D) Activation of CAMP production by Insulin
Description : Beta adrenergic blockers lower intraocular tension by: A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors B. Constricting ciliary blood vessels ... action on trabecular meshwork D. Reducing aqueous formation unrelated to beta adrenoceptor mediation
Last Answer : A. Down regulating adenylyl cyclase in ciliary body through reduced activation of β2 adrenoceptors
Description : In the neurone: a. the magnitude of the action potential is dependent on the strength of the stimulus b. impulses can travel in both direction c. depolarization is accompanied by increased ... potassium ions d. during depolarization, the potential of the neurone changes from -70mV to +40mV
Last Answer : during depolarization, the potential of the neurone changes from -70mV to +40mV
Description : The resting membrane potential of a cell a. is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+ b. falls to zero immediately when Na+ ... the equilibrium potential for Na+ e. is markedly altered if the extracellular Na+ concentration is increased
Last Answer : is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+
Description : Hormonal stimulation of the formation of the second messenger inositol 1,4,5 triphosphate (IP3) quickly leads to the release of which other intracellular messenger? (A) cAMP (B) Prostaglandin (C) Calcinon (D) Leukotriene
Description : The following kinin action is mediated primarily by the kinin B1 receptor: A. Intestinal contraction B. Bronchoconstriction C. EDRF release and vasodilatation D. Production of Interleukin, TNFα and other inflammatory mediators
Last Answer : . Production of Interleukin, TNFα and other inflammatory mediators
Description : Select the correct statement about benzodiazepines (BZDs): A. All BZDs facilitate GABA mediated Cl¯ influx into neurones B. Different BZDs exert the same degrees of hypnotic, anxiolytic and anticonvulsant ... at all neuronal sites D. The muscle relaxant action of BZDs is not blocked by flumazenil
Last Answer : A. All BZDs facilitate GABA mediated Cl¯ influx into neurones
Description : Which are the cholesterol esters that enter cells through the receptor-mediated endocytosis of lipoproteins hydrolyzed? (A) Endoplasmin reticulum (B) Lysosomes (C) Plasma membrane receptor (D) Mitochondria
Last Answer : B
Last Answer : (B) Lysosomes
Description : What is true of risperidone: A. It is an atypical neuroleptic which produces few extrapyramidal side effects B. It has combined dopamine D2 and 5-HT2 receptor blocking activity C. It does not cause hyperprolactinemia D. Both 'A' and 'B' are correct
Last Answer : D. Both 'A' and 'B' are correct
Description : Compared to other antipsychotic drugs, the distinctive feature of penfluridol is: A. Very long duration of action B. Weak dopamine D2 blocking activity C. Lack of extrapyramidal side effects D. Additional 5-HT2 receptor blocking activity
Last Answer : A. Very long duration of action
Description : The following 5-HT receptor is not a G protein coupled receptor: A. 5-HT1 B. 5-HT2 C. 5-HT3 D. 5-HT4
Last Answer : C. 5-HT3
Description : The primary mechanism underlying the resistance of gram-positive organisms to macrolide antibiotics is (a) Methylation of binding sites on the 50S ribosomal subunit (b) Formation of ... ) Formation of drug-inactivating acetyltranferases (e) Decreased drug permeability of the cytoplasmic membrane
Last Answer : Ans: A
Description : The symptoms of allergen-mediated asthma result from which of the following? (a) Increased release of mediators from mast cells (b) Increased adrenergic responsiveness of the airways (c) ... bronchial tissue (d) Decreased calcium influx into the mast cell (e) Decreased prostaglandin production
Description : The Symptoms of allergen-mediated asthma result from which of the following? (a) Increased release of mediators from mast cells (b) Increased adrenergic responsiveness of the airways (c) ... bronchial tissue (d) Decreased calcium influx into the mast cells (e) Decreased prostaglandin production
Description : The vasopressin action(s) mediated by V2 receptors include(s): A. Increased water permeability of collecting duct cells B. Increased urea permeability of collecting duct cells C. Vasoconstriction D. Both 'A' and 'B
Last Answer : D. Both 'A' and 'B
Description : Which is associated with a steroid hormone? A) cyclic AMP B) the second messenger system C) production of new proteins D) activation of proteins present in an inactive form E) binding of a protein to a surface receptor on the plasma membrane
Last Answer : C) production of new proteins
Description : Which of the following is activated by Cholera toxin? 1) Adenylate cyclase 2) Guanlyate cyclase 3) Peroxisome proliferator receptor (PPAR) gamma 4) Sodium/potassium ATPase 5) The glucose-sodium transporter
Last Answer : Answers-1 Cholera toxin activates adenylate cyclase with generation of cAMP.
Description : Binding of insulin to its receptor activates (A) Adenylate cyclase (B) Guanylate cyclase (C) Phospholipase C (D) Tyrosine kinase
Last Answer : Answer : D
Description : Drugs that block the a receptor on effector cells at adrenergic nerve endings (a) Antagonize the effects of isoproterenol on the heart rate (b) Antagonize some of the effects of epinephrine on ... the effects of epinephrine on adenylyl cyclase (d) Cause mydriasis (e) Decreases blood glucose levels
Description : The dopamine D2 receptor has the following feature: A. It is excitatory in nature B. It is negatively coupled to adenyl cyclase C. It is selectively blocked by bromocriptine D. It is not blocked by metoclopramide
Last Answer : B. It is negatively coupled to adenyl cyclase
Description : The receptor transduction mechanism with the fastest time-course of response effectuation is: A. Adenylyl cyclase-cyclic AMP pathway B. Phospholipase C-IP3: DAG pathway C. Intrinsic ion channel operation D. Protein synthesis modulation
Last Answer : C. Intrinsic ion channel operation
Description : The following H1 antihistaminic has additional anti 5-HT, anticholinergic, sedative and appetite stimulating properties: A. Promethazine B. Terfenadine C. Cyproheptadine D. Hydroxyzine
Last Answer : C. Cyproheptadine
Description : Dysmenorrhoea is often associated with excess production of the following autacoid by the endometrium: A. Bradykinin B. Prostaglandin C. Platelet activating factor D. 5-Hydroxytryptamine
Last Answer : B. Prostaglandin
Description : The ‘amine’ ergot alkaloid differs from ‘amino acid’ ergot alkaloid in that it has: A. High oral bioavailability B. Better CNS penetrability C. Weaker oxytocic action D. Strong anti-5-HT action
Last Answer : A. High oral bioavailability