Protein profiles of microsections of the fetal and adult human lens during development and ageing

Abstract

The water-soluble proteins of the human fetal lens (175- and 285-day-old) contain HM-, pre-alpha-, alpha-, beta- and gamma-crystallins. Using the frozen-sectioning technique, it can be demonstrated that the fetal lens does not have an homogeneous distribution of crystallins, but there are gradual differences between the cortices and the nucleus. The frozen-sectioning technique shows for the adult lens significantly increasing amounts of beta-crystallins of pI 4.95-5.55, especially at the posterior supra-nuclear layer, increasing amounts of HM-crystallins and decreasing amounts of beta-crystallins of pI 5.80-7.05 in the nucleus. This microsectioning technique was correlated with Scheimpflug photographs of the fetal and adult lens. In the fetal lens, the anterior capsule and 2 peaks in the anterior and posterior supranuclear layers could be visualized after densitometry. In the adult lens 5 layers could be demonstrated, e.g. the anterior capsule, the anterior supranuclear layer, the nucleus, the posterior supranuclear layer and the anterior capsule.