A 70-year-old man with long-standing hypertension develops left ventricular hypertrophy. The increased myocardial cell size is primarily driven by mechanical stretch and vasoactive agents like angiotensin II. Which signaling pathway is most directly responsible for initiating the pathological hypertrophic gene response in cardiomyocytes?
- A PI3K-Akt pathway
- B G protein-phospholipase C pathway ✓
- C JAK-STAT pathway
- D Wnt-beta catenin pathway
Correct answer: B. G protein-phospholipase C pathway
Explanation
Mechanical stretch and vasoactive agents like angiotensin II activate G protein-coupled receptors, which stimulate phospholipase C. This generates IP3 and DAG, leading to PKC activation and subsequent pathological hypertrophic gene expression. The PI3K-Akt pathway is more associated with physiological hypertrophy, such as in athletes. JAK-STAT and Wnt pathways are involved in cytokine signaling and development, not pressure overload hypertrophy.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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