[Search for chaperon-like anticataract drugs, the antiaggregants of lens crystallins. Communication. 1. Chaperon-like activity of N-acetyl carnosine dipeptide: in vitro study on a model of ultraviolet-induced aggregation of betaL-crystallin].

Aggregation ofcrystallins, the lens proteins, is one of the basic stages of cataract formation. Among the protein aggregation models used to study the molecular mechanisms of the initial stages of lenticular opacity, UV-induced aggregation of betaL-crystallin is most close to the in vivo conditions. The carnosine derivative N-acetyl carnosine has been shown to be effective in inhibiting the UV-induced aggregation of betaL-crystallin. Examination of the accumulation kinetics of carbonyl groups in betaL-crystallin under UV irradiation has indicated that neither carnosine nor N-acetyl carnosine fails to affect this parameter--an indicator of oxidative protein damage. By taking into account also the fact that N-acetyl carnosine is not an antioxidant, it can be believed that the molecular mechanism of action of this compound on UV-induced aggregation of betaL is unassociated with its antioxidative properties. The authors hypothesize that the molecular chaperon-like properties similar to those of alpha-crystallin underlie the mechanism of action of the acetyl derivative carnosine. The prospects for searching anticataract agents of a new chaperon-like class are discussed.

[Chaperon-like anticataract agents, the antiaggregants of lens crystallin. Communication 4. Study of the effect of a mixture of di- and tetrapeptides on a prolonged rat model of UV-induced cataract].

There is a potential of therapeutic action on certain stages of caractogenesis, in particular on the aggregation of water-soluble proteins of cytoplasmic lens fiber cells, giving rise to insoluble protein complexes. The effect of a combined preparation (N-acetyl carnosine and D-patethine), acting by the chaperon-like mechanism, was studied in vivo on a prolonged rat model of UV-induced cataract. The use of the combined preparation consisting of a mixture of peptides of N-acetyl carnosine and D-patethine in a ratio of 1:1 as ocular instillations and intraperitoneal injections could slow down the development of UV-induced cataract in vivo. Pathomorphological studies suggest that the combined preparation has a protective effect on lens tissue when the rat model of UV-induced cataract is employed.