This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'ACE inhibitors are contraindicated in bilateral renal aery stenosis, because - \nSelect and explain. \nA. Angiotensin II has direct effect on GFR, B. Enhances bradykinin action, C. Hyperreninism affects renal parenchyma, D. Affects prostaglandins', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Angiotensin II has direct effect on GFR o Patients with renal aery stenosis are dependent on efferent aeriolar vasoconstiction for maintenance of glomerular filtration pressure. Angiotensin II is responsible for vasoconstriction of efferent aeriole. o ACE inhibitors prevent the generation of Angiotensin II. This causes dilatation of efferent aerioles and fall in glomerular filtration pressure. This can ppt renal failure. o Therefore ACE inhibition are C/I in patients with bilateral renal aery stenosis.", 'role': 'assistant'}]