Age-related changes in normal human basement membrane

Basement membranes were studied in the seminiferous tubules of the male, and capillaries of the pectoralis muscles in "normal" males and females. Age-related changes in basement membrane thickness were investigated on electromicrographs by quantitative morphometry. Specimens obtained from either autopsies or surgical procedures were divided into four different age groups ranging from age 16 to age 87 years. The results show a statistically significant increase in the basement membrane thickness correlated with age, in basement membranes associated with both mesenchymal (capillaries) and epithelial (testes) tissue. A comparison of capillary basement membrane in the pectoralis muscle and seminiferous tubule basement membrane in the male show a constant increase in thickness until the age of 60 years, following which only slight increases were noted. The basement membrane thickness in capillaries of the pectoralis muscle in females showed linear increases throughout the lifespan, although at a lowerrate than in the male; at age 80 years, it had the same thickness as the male. A comparison of basement membrane thickness between the youngest and oldest groups showed an increase of approximately 50% in all tissues studied.