Glucagon MCQs With Answer provide B. Pharm students a focused review of glucagon’s physiology, pharmacology, mechanism of action, therapeutic uses and clinical implications. This set covers synthesis and processing of proglucagon, alpha‑cell secretion, glucagon receptor signaling (Gs‑protein, cAMP, PKA), hepatic glycogenolysis and gluconeogenesis, metabolic effects on adipose and heart, clinical formulations and emergency use for severe hypoglycaemia, diagnostic applications, side effects and new drug targets such as receptor antagonists. Each question reinforces molecular pathways, clinical dosing, contraindications and interpretation of lab assays to deepen understanding for exams and practical practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Where is glucagon primarily synthesized?
- Pancreatic beta cells
- Pancreatic alpha cells
- Pancreatic delta cells
- Intestinal L‑cells
Correct Answer: Pancreatic alpha cells
Q2. Which prohormone convertase predominantly processes proglucagon to glucagon in pancreatic alpha cells?
- Prohormone convertase 1/3 (PC1/3)
- Prohormone convertase 2 (PC2)
- Dipeptidyl peptidase‑4 (DPP‑4)
- Furin
Correct Answer: Prohormone convertase 2 (PC2)
Q3. Which G protein is coupled to the glucagon receptor?
- Gi
- Gs
- Gq
- G12/13
Correct Answer: Gs
Q4. What is the immediate hepatic metabolic action of glucagon after receptor activation?
- Stimulates glycogenolysis
- Stimulates glycogen synthesis
- Increases glycolysis
- Decreases gluconeogenesis
Correct Answer: Stimulates glycogenolysis
Q5. What is the principal second messenger mediating glucagon’s intracellular effects?
- Inositol trisphosphate (IP3)
- cAMP
- Diacylglycerol (DAG)
- Calcium ion (Ca2+)
Correct Answer: cAMP
Q6. Which enzyme is directly activated by PKA in the pathway leading to glycogen breakdown?
- Glycogen synthase
- Phosphorylase kinase
- Hexokinase
- Pyruvate dehydrogenase
Correct Answer: Phosphorylase kinase
Q7. Which clinical situation is an established indication for emergency administration of glucagon?
- Mild hyperglycaemia
- Severe hypoglycaemia with unconscious patient and no IV access
- Chronic type 2 diabetes management
- Routine postprandial glucose lowering
Correct Answer: Severe hypoglycaemia with unconscious patient and no IV access
Q8. Which routes are commonly used to administer emergency glucagon preparations?
- Oral tablet
- Transdermal patch
- Intramuscular, subcutaneous or intravenous injection
- Inhalation powder
Correct Answer: Intramuscular, subcutaneous or intravenous injection
Q9. What is the primary metabolic effect of glucagon on adipose tissue?
- Stimulates lipogenesis
- Stimulates lipolysis
- Inhibits hormone‑sensitive lipase
- No effect on lipid metabolism
Correct Answer: Stimulates lipolysis
Q10. What is the approximate plasma half‑life of endogenous glucagon?
- 30 seconds
- 3–6 minutes
- 1 hour
- 24 hours
Correct Answer: 3–6 minutes
Q11. Which hormone is considered the primary counter‑regulatory hormone to insulin during fasting?
- Insulin
- Glucagon
- Somatostatin
- GLP‑1
Correct Answer: Glucagon
Q12. Which nutrient strongly stimulates glucagon secretion from alpha cells?
- High plasma glucose
- Amino acids (e.g., arginine)
- Free fatty acids
- Ketone bodies
Correct Answer: Amino acids (e.g., arginine)
Q13. What cardiac effect can glucagon exert via increased cAMP in cardiomyocytes?
- Negative inotropy and bradycardia
- Positive inotropy and chronotropy
- No direct cardiac effect
- Only vasodilation without inotropic change
Correct Answer: Positive inotropy and chronotropy
Q14. Which therapeutic strategy targets glucagon signaling to lower hepatic glucose output in type 2 diabetes?
- GLP‑1 receptor agonists
- Glucagon receptor antagonists
- SGLT2 inhibitors
- Insulin secretagogues
Correct Answer: Glucagon receptor antagonists
Q15. In which condition is administration of glucagon relatively contraindicated due to risk of catecholamine release?
- Pregnancy
- Pheochromocytoma
- Chronic kidney disease
- Hypothyroidism
Correct Answer: Pheochromocytoma
Q16. Glucagon stimulation test is commonly used clinically to assess reserve of which pituitary axis?
- Thyroid axis (TSH)
- Growth hormone (GH) secretion
- Posterior pituitary (ADH)
- Gonadotropin axis (LH/FSH)
Correct Answer: Growth hormone (GH) secretion
Q17. Which peptide derived from proglucagon processing in intestinal L‑cells enhances insulin secretion?
- Glucagon
- GLP‑1 (glucagon‑like peptide‑1)
- Somatostatin
- Insulin‑like growth factor
Correct Answer: GLP‑1 (glucagon‑like peptide‑1)
Q18. Which organs are primarily responsible for glucagon clearance from plasma?
- Spleen and bone marrow
- Liver and kidney
- Lung and thyroid
- Pancreas and adrenal gland
Correct Answer: Liver and kidney
Q19. Which amino acid is a major gluconeogenic substrate whose uptake is promoted during glucagon action?
- Methionine
- Alanine
- Lysine
- Phenylalanine
Correct Answer: Alanine
Q20. Which intracellular enzyme is directly activated by rising cAMP following glucagon receptor activation?
- Adenylate cyclase
- Protein kinase A (PKA)
- Protein kinase C (PKC)
- Phospholipase C
Correct Answer: Protein kinase A (PKA)
Q21. Elevated glucagon-to‑insulin ratio promotes which of the following hepatic processes?
- Decreased ketogenesis
- Increased ketogenesis
- Enhanced glycogen synthesis
- Suppressed gluconeogenesis
Correct Answer: Increased ketogenesis
Q22. Which of the following is NOT a therapeutic use of glucagon?
- Treatment of severe hypoglycaemia
- As a radiologic agent to relax the gut in imaging
- Diagnostic stimulation test for GH
- Long‑term treatment to reduce chronic hyperglycaemia in diabetes
Correct Answer: Long‑term treatment to reduce chronic hyperglycaemia in diabetes
Q23. Which adverse effects are most commonly reported after therapeutic glucagon administration?
- Severe hypertension and ischemia
- Nausea and vomiting
- Delayed prolonged hypoglycaemia
- Neutropenia
Correct Answer: Nausea and vomiting
Q24. Which toxicological application of glucagon is clinically useful?
- Treatment of beta‑blocker overdose
- Worsening beta‑blocker toxicity
- Contraindicated in calcium channel blocker overdose
- Enhances effects of beta‑blockers
Correct Answer: Treatment of beta‑blocker overdose
Q25. Glucagon receptor expression is highest in which tissue?
- Skeletal muscle
- Liver
- Brain cortex
- Pancreatic beta cells
Correct Answer: Liver
Q26. How does abnormal glucagon secretion contribute to type 2 diabetes?
- Reduced glucagon causes fasting hyperglycaemia
- Increased glucagon contributes to elevated hepatic glucose output
- No role in diabetic hyperglycaemia
- Only insulin abnormalities matter in type 2 diabetes
Correct Answer: Increased glucagon contributes to elevated hepatic glucose output
Q27. Which laboratory method is commonly used to quantify circulating glucagon levels?
- Polymerase chain reaction (PCR)
- Enzyme‑linked immunosorbent assay (ELISA)
- Magnetic resonance imaging (MRI)
- Mass spectrometric lipid profiling
Correct Answer: Enzyme‑linked immunosorbent assay (ELISA)
Q28. What is the approximate amino acid length of human glucagon?
- 10 amino acids
- 29 amino acids
- 100 amino acids
- Precise steroid structure
Correct Answer: 29 amino acids
Q29. What is the effect of glucagon on hepatic pyruvate kinase activity?
- Activates pyruvate kinase
- Decreases pyruvate kinase activity via phosphorylation
- No effect on pyruvate kinase
- Converts pyruvate kinase to a constitutively active isoform
Correct Answer: Decreases pyruvate kinase activity via phosphorylation
Q30. Which gluconeogenic enzyme’s expression is induced by glucagon signalling in the liver?
- Hexokinase
- PEP carboxykinase (PEPCK)
- Pyruvate kinase
- Glycogen synthase
Correct Answer: PEP carboxykinase (PEPCK)
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