Cellular and Molecular Anatomy of the Zona Glomerulosa in Primary Hyperaldosteronism: A Proteomic and Ultrastructural Investigation Using Adrenal Adenoma Specimens from Nigerian Patients

Primary hyperaldosteronism is the most common cause of secondary hypertension and is associated with aldosterone-producing adrenal adenomas arising from the zona glomerulosa of the adrenal cortex. Despite the high burden of hypertension in Nigeria, the cellular and molecular anatomical characterisation of adrenal zona glomerulosa pathology in Nigerian aldosterone-producing adenoma specimens has not been performed. This study aims to conduct a comprehensive cellular and molecular anatomical investigation of the zona glomerulosa in aldosterone-producing adenoma specimens from Nigerian hypertensive patients compared with non-functioning adrenal adenoma controls. Adrenal specimens collected during laparoscopic adrenalectomy at five major centres spanning the South West, South South, and South East zones will be processed for electron microscopy to characterise zona glomerulosa mitochondrial morphology, lipid droplet density, and nuclear pleomorphism at ultrastructural resolution. Immunohistochemistry for CYP11B2 (aldosterone synthase), steroidogenic acute regulatory protein, and proliferating cell nuclear antigen will characterise steroidogenic activity and growth dynamics. Proteomic analysis by liquid chromatography-tandem mass spectrometry will identify differentially expressed proteins between aldosterone-producing adenoma and non-functioning adenoma zones. This study will generate the first original cellular and molecular anatomical profile of aldosterone-producing adenomas from Nigerian patients, contributing mechanistic insights into hyperaldosteronism pathobiology with direct relevance to Nigerian hypertension management.

Keywords: adrenal cortex, aldosterone-producing adenoma, primary hyperaldosteronism, proteomics, zona glomerulosa