POLYCYSTIN EXPRESSION DURING EMBRYONIC-DEVELOPMENT OF HUMAN KIDNEY INADULT TISSUES AND ADPKD TISSUE

Normal renal tissue, ranging from 8 weeks' gestation to full term to a dult, was probed with polyclonal antibodies raised to peptide epitopes within the translated PKD1 gene sequence. Three antibodies were studi ed, all of which gave similar results. Renal tissue from patients with autosomal dominant polycystic kidney disease (ADPKD) and samples from normal adult liver, heart, brain, skeletal muscle and lymph node were also studied. Tissue staining demonstrated that the pattern of polycy stin expression changed with gestational age in normal kidney. Whereas the precursors to the renal excretory unit were stained at 12 weeks, and the proximal and distal convoluted tubules stained to differing de grees throughout development, the glomeruli were poorly stained until full term and also in the adult. Extrarenal tissue stained in both adu lt and juvenile samples, with the exception of lymph node, which remai ned unstained. The intensity of polycystin staining increased in ADPKD renal tissue. The widespread distribution of polycystin was consisten t with the systemic nature of ADPKD and the role of epithelial cells i n the disease.