The influence of hypodynamic stress on ultrastructure of the cortical layer cells of eye lens

Saulius Kušleika, Alvydas Paunksnis, Marija Kušleikaitė¹

Department of Ophthalmology, Institute for Biomedical Research, ¹Institute of Cardiology, Kaunas University of Medicine, Lithuania

Key words: hypodynamic stress, eye, lens, ultrastructure.

Summary. The aim of the study was to determine the influence of 48-day hypodynamic stress on the ultrastructure of the cortical layer cells of eye lens. Hypodynamic stress was induced in Chinchilla male rabbits (weight 2.5–3.0 kg; n=8) by placing them in metal hutches for 48 days. Rabbits (n=8) of the control group (non-stressed) were kept under normal vivarium conditions. Following the hypodynamic regime (after 48 days) the rabbits (stressed and control) were anaesthetized using thiopental sodium (35 mg/kg). On removing their eyes, the cortical partes of lenses were prepared and immersed into a fixative solution containing 2% paraformaldehyde and 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.4) for more than 4 hours at room temperature or overnight at 4°C. The specimens were then postfixed, dehydrated and embedded in a mixture of Epon 812 and Araldite. Ultrathin sections stained with uranyl acetate and lead citrate were evaluated by electron microscopy (Philips-300). Microscopical examination of the cortical layer cells of lenses showed extensive cellular vacuolization, calcification, and formation of a light scattering center. Cortical fibers were found to be compacted along their length, and elongated with decreased interdigitations.

Conclusion. Thus, intensive long-term hypodynamic stress caused ultrastructural eye lens damages associated with cataractogenesis.

Correspondence to S. Kušleika, Department of Ophthalmology, Institute for Biomedical Research, Kaunas University of Medicine, Eivenių 2, 50009 Kaunas, Lithuania. E-mail: kusleiks@takas.lt

Received 14 May 2004, accepted 15 September 2004