Which of the following neurotransmitters is involved in Parkinson′s disease?

Correct Answer: C

Rationale: The correct answer is C: Dopamine. Parkinson's disease is characterized by a loss of dopamine-producing neurons in the brain. Dopamine is crucial for controlling movement and coordination, and its deficiency leads to symptoms of Parkinson's. Acetylcholine (Choice A) is not primarily involved in Parkinson's disease, and excess glutamate (Choice B) can actually be harmful in neurodegenerative disorders. Choice D is incorrect as acetylcholine and glutamate are not directly related to Parkinson's disease.

Correct Answer: A

Rationale: The correct answer is A: Agranulocytosis. Analgin can cause a serious side effect called agranulocytosis, which is a condition where the bone marrow stops producing enough white blood cells, leaving the body vulnerable to infections. This limits the usefulness of Analgin as the risk of developing agranulocytosis outweighs its benefits. Summary of other choices: B: Erosions and gastric bleeding - While Analgin can cause gastrointestinal side effects like erosions and bleeding, these are not as severe or limiting as agranulocytosis. C: Methemoglobinemia - Although Analgin can lead to methemoglobinemia, it is a rare side effect compared to agranulocytosis. D: Hearing impairment - There is no significant evidence linking Analgin to hearing impairment, making this choice incorrect.

Correct Answer: B

Rationale: The correct answer is B: Tranylcypramine. Tranylcypramine is an unselective MAO blocker, inhibiting both MAO-A and MAO-B, leading to long-lasting enzyme inhibition. Moclobemide (A) is a reversible MAO-A inhibitor. Selegiline (C) is a selective MAO-B inhibitor. Fluoxetine (D) is a selective serotonin reuptake inhibitor (SSRI) and does not inhibit MAO enzymes. Therefore, Tranylcypramine is the correct choice for producing long-lasting MAO inhibition.

Correct Answer: A

Rationale: The correct answer is A because caffeine actually stimulates gastric secretion, not inhibits it. Caffeine can increase stomach acid production, leading to potential digestive issues. Choices B, C, and D are incorrect because caffeine is known to cause hyperglycemia by increasing blood sugar levels, has a moderate diuretic action by increasing urine production, and increases free fatty acids in the bloodstream, which can affect metabolism. Therefore, based on its effects on gastric secretion, A is the correct answer.

Correct Answer: B

Rationale: The correct answer is B: More addictive and fast-acting. Heroin is derived from morphine and is more potent, leading to a faster onset of action and increased addictive potential. The rapid crossing of the blood-brain barrier contributes to its fast-acting properties. It is crucial to differentiate between heroin and morphine due to their varying addictive nature and speed of action. Choices A, C, and D are incorrect because heroin is not typically used clinically, is not more effective orally, and is actually more potent and faster-acting than morphine, making it not less potent and long-acting.