Ultrastructure and elastic changes of regenerated basement membrane in normal and diabetic rats.

Basement membrane of the lens capsule was shown by partial enzymic digestion to be composed of thick (2.5 mn-3.3 nm in diameter) and thin (1.4 nm-2.2 nm) filaments. Much thinner filaments or strands (0.5-1.1 nm) projected from the ends of some of the thicker filaments or were occasionally seen separately. From the measurement of Young's modulus of elasticity the proportion of thick and thin filaments in normal membrane were compared with those seen in regenerated normal membrane, diabetic membrane, and regenerated diabetic membrane. In all these abnormal membranes where growth had been disturbed the percentage of thick filaments was reduced.