Changes in the structure and properties of corpus vitreous and the preservation of enzymatic composition of rabbit antioxidative system under the influence of sulphur hexafluoride gas.

PURPOSE: To evaluate clinical, physiochemical and biochemical changes in rabbit vitreous body caused by local injection of sulphur hexafluoride gas. MATERIAL AND METHODS: The volume of fluid vitreous fraction was measured with Na+, K+, Mg2+, Ca2+ levels and full proteins concentration in both vitreous fractions in 24 New Zealand rabbits at 2, 7 and 14 day after SF6 injection. The activity of superoxide dismutase, catalase and malonyl dialdehyde were used to evaluate the activity of antioxidative enzymatic system. Control group consisting of 6 New Zealand rabbits had no experimental procedures. RESULTS: In the investigated group, the fluid vitreous fraction volume was increased while gelatous one was diminished from 0.08 ml in control group to 0.32 ml in the study group (on day 14). The level of Na+, K+, Mg2+, Ca2+ in the fluid fraction was unchanged. On day 7, we noticed statistically significant increase in protein concentration in comparison with the control group and the study group on 14 day. The activity of superoxide dismutase and catalase as well as the level of malonyl dialdehyde were increased in the fluid vitreous fraction compared to the gelatous one in the control group. After the SF6 injection we did not observe any changes of superoxide dismutase and catalase activities in the gelatous part of vitreous body while in the fluid one there was statistically significant decrease in the enzymatic activity and the MDA level in the whole observation time. CONCLUSIONS: The injected sulphur hexafluoride gas caused the damage of the gelatous vitreous fraction with the increase in the fluid one. The oxygen free radicals might trigger these pathological processes.

[Lacrimation disorders in workers chronically exposed to petroleum derivatives]. / Zaburzenia wydzielania lez u pracowników narazonych na przewlekle oddzialywanie pochodnych ropy naftowej.

Lacrimal fluid plays a very significant role in maintaining proper functions of conjuctivas, cornea and eyelids. The fluid is secreted by the main lacrimal gland and additional glands. It produces the so called preocular lacrimal film. A number of clinical tests, such as Chirmer's tests I and II, break-up-time (BUT), lysozyme, and flow tests are used in quantitative and qualitative analyses, as well as in the determination of the lacrimal film stability. The aim of work was to utilize these in assessing the lacrimal secretion and the lacrimal film stability in workers chronically exposed to petroleum derivatives. Fifty three workers from departments of acetobenzene, benzene and butadiene, phenol and acetone, sewage waters, asphalt oxidas, polyethylene and polypropylene, were eligible for the study (group I). During previous examinations, acquired disorders in colour perception were diagnosed in all the subjects by means of the Mansuella-Fansworth 100-Hue test. The age range was 25 to 56 years, with a mediane of 44.1 years +/- 6.5. Mean duration of employment was 22 years (SD +/- 8.25). The control group (group II) was composed of 28 men aged between 24 and 60 years with a median of 42.7 years +/- 6.3, never employed under conditions of exposure to toxic chemicals. On the right eye of each subject Schirmer's test was performed after instilling into the conjunctival sac 1-2 drops of Alcain solution according to Whitcher. Five min following anesthesia of the conjunctival sac, a standardised belt of blotting-paper with colour dampness markers Vidisic (Dr Mann Pharma GMBH, Germany) was placed in the vicinity of the external angle of the eye. After 5 min the degree of the belt dampness was measured in millimetres. After 30 min the break-up-time test was performed on the left eye. Fluorescein was released to conjunctival sac from a sterile belt of blotting-paper (Haag-Strait Co.). A slit lamp with cobalt filter was used to calculate time (in sec) that elapsed between opening of the lid slit and the first symptom of breaking-up the lacrimal film. The results obtained were presented in the form of arithmetic means and standard deviation values +/- SD. Schirmer's test was 13.40 +/- 7.43 mm in group 1, and 22.54 +/- 8.25 mm in the control group, mean values differed significantly, p < 0.01. Lacrimal film break-up-time was 16.30 +/- 6.19 sec in group 1, and 31.48 +/- 7.96 sec in the control group, mean values differed significantly, p < 0.01. In persons chronically exposed to petroleum derivatives, statistically significant decrease in lacrimal secretion, as well as shortening of lacrimal film break-up-time were found when compared with the control group.

[Changes in the antioxidant system of the vitreous in rabbits after administration of sulfur hexafluoride]. / Zmiany w ukladzie antyoksydacyjnym ciala szklistego królików po podaniu szesciofluorku siarki.

PURPOSE: To evaluate the enzymatic activity of antioxidant system of rabbit's vitreous after sulfur hexafluoride (SF6) application. MATERIAL AND METHODS: Activity of CuZn-SOD, catalase and concentration of MDA in fluid and gel fraction of vitreous were determined in 24 rabbits of New Zealand race on the 2nd, 7th and 14th day after SF6 application. Control group consisted of 6 animals which did not undergo any operations. RESULTS: Dismutase and catalase activity as well as MDA concentration were higher in fluid fraction than in gel fraction in animals of control group. After SF6 application the activity of enzymes and MDA concentration did not change, whereas in fluid fraction all these values were statistically significantly reduced in all time intervals. CONCLUSIONS: SF6 leads to disintegration of vitreous structure especially just after its application. Damage to hyalocytes causes dysfunction of enzymatic system. Specific fluid fraction structure and insufficient number of substrates for peroxidation processes are the reasons for simultaneous reduction of MDA concentration.

[Changes in the antioxidant system of the aqueous humor, lens and erythrocytes after sulfur hexafluoride application to the vitreous of rabbits]. / Zmiany w ukladzie antyoksydacyjnym cieczy wodnistej, soczewce i krwinkach czerwonych krwi obwodowej po podaniu szesciofluorku siarki do ciala szklistego królików.

AIM: To determine the activity of superoxide dismutase, catalase and the concentration of malondialdehyde (MDA) in aqueous humor, lens and red blood cells after application of sulfur hexafluoride (SF6) into vitreous of rabbits. MATERIAL AND METHODS: 0.5 ml of 100% SF6 was injected into the vitreous of 24 rabbits of New Zealand race. The animals were randomly divided into 3 groups (of 8 rabbits each) depending on the observation day: group 1-2nd day of experiment, group 2-7th day and group 3-14th observation day. The control group (gr. 0) consisted of 6 rabbits that did not undergo any operations. Activity of superoxide dismutase, catalase and MDA concentration were determined in aqueous humor, lens and systemic blood erythrocytes. RESULTS: On the 7th day of observation an increased activity of dismutase and catalase as well as simultaneous increased MDA concentration were observed. In the lens on the 7th day the increased activity of dismutase was significant in relation to the results in the next time interval, whereas MDA concentration was significantly lower in all time intervals of the experiment in comparison with control group. In erythrocytes an increased activity of catalase was noticed on the 2nd and 14th day. CONCLUSIONS: Increased occurrence of active oxygen species in aqueous humor leads to insufficiency of the antioxidant system and intensification of peroxidation processes, which is reflected by increased MDA concentration. However, in the lens of this experimental model a slight stimulation of antioxidant system by a small number of free radicals is observed, which provokes a reaction of sweeping them away. Efficiency of lens antioxidant system is secured by weakening of peroxidation processes, which is expressed in minimal drop of MDA concentration.