Nucleotidic substances increase tear lysozyme levels in New Zealand white rabbits

Abstract

Abstract: : Purpose:The primary goal of the present work has been to analyse the effect some nucleotidic substances like UTP, Ap₄A and INS365 on rabbit tear lysozyme levels in order to know if these compounds can increase the amount of this protein in the tear film.Methods:Diffusion in Agar method was employed to get lysozyme levels in the tear film. Protein amount was obtained by measuring the inhibitory halos around a Whatman nº 1 disc of 5mm soaked in rabbit tears. Discs were put on Petri dishes with Agar medium where Micrococcus lisodeikticus was grown. After two control measurements, 10 µL of the studied compound was topically instilled in one eye, and the tear samples were collected every hour along 5 hours. Micrococcus lisodeikticus and Agar plates were incubated at 37ºC for 24 hours. A lysozyme standard curve for its quantification was performed with known concentrations of egg lysozyme as described elsewhere. Lysozyme amount was obtained by measuring the inhibitory halos around a Whatman nº1 disc of 5 mm soaked in rabbit tears along 6 hours. Discs were put on petri dishes with Agar medium where Micrococcus Lysodeitikus bacteria was grown. Results:All the tested substances have revealed an augment of tear lysozyme in rabbits. These results show a percentage of increase over the basal lysozyme levels of about 100% for UTP, 140% for Ap₄A and 165% for INS365. Conclusions:These substances could enhance the bactericidal activity of tear film by means of increasing the tear lysozyme protein in New Zealand white rabbits.

Keywords: lacrimal gland • cornea: tears/tear film/dry eye • cornea: tears/tear film/dry eye