Which of the following substances is synthesized within vessel walls and inhibits thrombogenesis?

Correct Answer: B

Rationale: The correct answer is B: Prostacyclin (PGI2). Prostacyclin is synthesized within vessel walls and acts as a potent inhibitor of thrombogenesis by inhibiting platelet aggregation and promoting vasodilation. Thromboxane A2 (TXA2) (Choice A) is synthesized by platelets and promotes platelet aggregation. Prostaglandin E (PGE) (Choice C) is involved in various physiological processes but does not specifically inhibit thrombogenesis. Choice D is incorrect as Prostacyclin is indeed synthesized within vessel walls and inhibits thrombogenesis.

Correct Answer: B

Rationale: The correct answer is B: Propranolol. Propranolol is a nonselective beta-blocker, meaning it blocks both beta-1 and beta-2 adrenergic receptors. This leads to effects such as decreased heart rate, reduced blood pressure, and bronchoconstriction. Atenolol (choice A) and Metoprolol (choice C) are selective beta-1 blockers, primarily affecting the heart. Nebivolol (choice D) is a beta-1 blocker with vasodilatory properties. By blocking both beta-1 and beta-2 receptors, Propranolol has a wider range of effects compared to the other choices.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Ergot and indol derivatives, along with NSAIDs, are indeed main agents for acute migraine attack treatment. Ergot derivatives like ergotamine and dihydroergotamine are vasoconstrictors that help alleviate migraine symptoms by reducing blood flow in the brain. Indol derivatives like sumatriptan are serotonin receptor agonists that also help relieve migraines. NSAIDs like ibuprofen can help reduce inflammation and pain associated with migraines. Therefore, the statement is true. Summary of other choices: B: FALSE - This choice is incorrect as the statement in the question is true. C: Null - This choice is incorrect as it does not provide any relevant information to the question. D: All - This choice is incorrect as it implies that all agents are main agents for acute migraine attack treatment, which is not accurate.

Correct Answer: D

Rationale: Step 1: Sulphonylureas are a class of drugs that stimulate insulin release. Step 2: They act by binding to the sulphonylurea receptor on beta islet cells of the pancreas. Step 3: This binding triggers a cascade of events leading to insulin release. Step 4: Insulin then helps lower blood glucose levels. Conclusion: Choice D is correct as it accurately describes the mechanism of action of sulphonylureas. Choices A, B, and C are incorrect as they do not reflect the primary mode of action of sulphonylureas.

Correct Answer: D

Rationale: The correct answer is D because glucocorticoids have a multi-faceted anti-inflammatory effect. 1. Glucocorticoids inhibit phospholipase A2, reducing prostaglandins and leukotrienes, which are pro-inflammatory mediators. 2. They also decrease macrophage migration to the site of inflammation, reducing inflammation. 3. Glucocorticoids decrease capillary permeability, which helps in reducing swelling and edema. Therefore, all of the above mechanisms contribute to the anti-inflammatory effect of glucocorticoids. Other choices are incorrect because they do not encompass all the key mechanisms involved in the anti-inflammatory effects of glucocorticoids.