Analysis of the results of retinal peptides application in different ages of Campbell rats with Retinitis Pigmentosa

The work concerns studying electrophysiological parameters and, based on histological studies, morphological parameters of the retina in different age groups of Campbell rats with Retinitis Pigmentosa (RP) before and after Retinalamin treatment. 50 Campbell rats, as an experimental model of inherited RP, were used in the study. Rats were divided into two age groups, with 25 rats in each. Group I consisted of newborns up to 3 weeks, and Group II consisted of adults aged 3.5 ± 0.3 months. Retinalamin injections were given parabulbarly to all animals for 10 days. The total bioelectrical activity of the a, b, and c waves and the average value of the b-wave amplitude were studied using the electroretinography (ERG) method. Also, the thickness of the outer nuclear layer of retinal pigment epithelium cells was studied in a histological examination. Studies were conducted before the start of Retinalamin injections and in dynamics after 10 and 30 days. According to the ERG results, a decrease in the total bioelectrical activity of the rat retina and the average b-wave amplitude were already observed in 19-day-old rats. A statistically significant increase in these indicators was observed in both groups after 10 and 30 days of Retinalamin injections. Histological analysis of retinal preparations also revealed positive changes after the peptide administrations. An improvement in morphological structures and thickening of the outer nuclear layer of retinal pigment epithelial cells were noted in both groups. More significant positive dynamics were in Group I of newborn rats. Conclusion. Retinalamin treatment in newborn and adult Campbell rats with retinitis pigmentosa stabilized the processes developing in the retina. At the same time, the maximum positive effect was manifested in newborn rats.