Correct option is D
Explanation-
Statement A: "Acidosis inhibits the secretion of cortisol by adrenal cortex" - INCORRECT
Acidosis does not inhibit cortisol secretion. In fact, glucocorticoids like cortisol may support renal acid-base regulation. So, this statement is incorrect.
Statement B: "The transcription of Na⁺-H⁺ antiporter gene is decreased by cortisol" - INCORRECT
Cortisol actually stimulates the transcription of the Na⁺/H⁺ exchanger (NHE) gene, promoting proton secretion. So this statement is false.
Statement C: "The translation of mRNA of 1Na⁺-3HCO₃⁻ symporter gene is decreased by cortisol" - INCORRECT
There is no evidence suggesting that cortisol inhibits this transporter’s translation. Cortisol typically aids in renal function and acid-base balance.
Statement D: "The secretion of endothelin-1 (ET-1) from the proximal tubule is enhanced in acidosis" - CORRECT
Yes, acidosis increases ET-1 secretion from proximal tubular cells. ET-1 is involved in adaptive responses, including increased acid secretion.
Statement E: "ET-1 stimulates the phosphorylation and subsequent insertion of the Na⁺-H⁺ antiporter into the apical membrane of proximal tubular cells" - CORRECT
ET-1 enhances Na⁺/H⁺ exchanger (NHE3) activity via phosphorylation and insertion into apical membrane, increasing H⁺ secretion.
Statement F: "The insertion of 1Na⁺-3HCO₃⁻ symporter into the basolateral membrane of proximal tubular cells is also increased by ET-1" - CORRECT
This is true. ET-1 upregulates Na⁺-3HCO₃⁻ symporter in the basolateral membrane, aiding in bicarbonate reabsorption, which helps compensate for acidosis.
Final answer-
Correct Statements:
D, E, and F — Option d
