Mechanism of urokinase action is an inhibition of Thromboxane A2. This statement is:

Correct Answer: B

Rationale: The correct answer is B: FALSE. Urokinase is a thrombolytic agent that activates plasminogen to plasmin, which dissolves blood clots. It does not inhibit Thromboxane A2. Thromboxane A2 is involved in platelet aggregation and vasoconstriction. Choices A, C, and D are incorrect because urokinase does not inhibit Thromboxane A2.

Correct Answer: B

Rationale: Verapamil is a calcium channel blocker that slows down the heart rate by blocking L-type calcium channels. This action helps in reducing blood pressure and controlling heart rhythm. Therefore, statement B stating that verapamil increases heart rate is incorrect. Choices A, C, and D are true as verapamil blocks L-type calcium channels, relaxes coronary artery smooth muscle, and depresses cardiac contractility, respectively.

Correct Answer: D

Rationale: Step-by-step rationale for why choice D is correct: 1. Growth hormone stimulates the synthesis or release of somatomedins, supporting statement A. 2. Low levels of IGF-1 are associated with dwarfism, validating statement B. 3. Hypersecretion of growth hormone can lead to acromegaly, confirming statement C. 4. Choice D is incorrect because growth hormone is contraindicated in subjects with open epiphyses, not closed ones. This is because GH can stimulate bone growth, potentially causing issues in individuals with open growth plates.

Correct Answer: D

Rationale: The correct answer is D because the statement that the half-life of glucagon is between 6 and 8 hours is FALSE. Glucagon's half-life is actually very short, around 5-10 minutes. This is due to rapid degradation by enzymes in the liver and kidneys. Glucagon is not stable in the bloodstream for long periods. A: Statement A is true as glucagon is indeed synthesized in the A cells of the pancreatic islets of Langerhans. B: Statement B is true as glucagon is a peptide consisting of a single chain of 29 amino acids, which is conserved across mammals. C: Statement C is true as glucagon is extensively degraded in the liver, kidneys, plasma, and at tissue receptor sites.

Correct Answer: C

Rationale: The correct answer is C: Celecoxib. Celecoxib is a selective COX-2 inhibitor, meaning it primarily targets the COX-2 enzyme, reducing inflammation and pain without affecting the protective COX-1 enzyme. This selective action reduces the risk of gastrointestinal side effects associated with traditional NSAIDs that inhibit both COX-1 and COX-2. Piroxicam (A), Indomethacin (B), and Diclofenac (D) are non-selective NSAIDs that inhibit both COX-1 and COX-2, leading to a higher risk of gastrointestinal complications.