Plasmin, a serine protease, was recently found to be involved in corneal ulcerative processes in humans and rabbits. In our experiments, plasmin activity was found in the tear fluid after mechanical and chemical damage of the rabbit cornea, such as de-epithelization and burning with alkali. The plasmin concentrations in the tear fluid were dependent on the severity of injury. The highest plasmin activity (2.0-3.0 micrograms ml-1) occurred after severe alkali damage to large areas of the cornea, and the lowest activity (0.4-1.0 micrograms ml-1) after mechanical injury (de-epithelization). Plasmin concentrations up to 1.0 micrograms ml-1 were associated with increased activities of lysosomal hydrolases in epithelial cells and keratocytes beneath the epithelium. Plasmin activities increased as the inflammatory reaction developed. When plasmin activity in the tear fluid was higher than 1.0 micrograms ml-1, inflammatory cells were found in the corneal stroma. Levels of 1.5-2.0 micrograms ml-1 were connected with higher numbers of inflammatory cells (particularly polymorphonuclear leukocytes) with increased activities of lysosomal hydrolases. Very high plasmin activities (2.5-3.0 micrograms ml-1) accompanied corneal ulcerative processes. The local application of aprotinin (Trasylol, Bayer), an inhibitor of plasmin, and also of some other proteases, was found to be necessary for the healing of severe corneal injuries in which highly elevated plasmin activity in the tear fluid and inflammatory cellulization of the cornea occurred (severe damage).(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• aprotinin farmakologie   terapeutické užití   MeSH
• beta-galaktosidasa metabolismus   MeSH
• dipeptidylpeptidasy a tripeptidylpeptidasy metabolismus   MeSH
• hydrolasy metabolismus   MeSH
• králíci MeSH
• lyzozomy enzymologie   MeSH
• neutrofily enzymologie   MeSH
• plasmin analýza   MeSH
• poranění rohovky * MeSH
• slzy enzymologie   MeSH
• vřed rohovky chemicky indukované   farmakoterapie   enzymologie   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aprotinin MeSH
• beta-galaktosidasa MeSH
• dipeptidylpeptidasy a tripeptidylpeptidasy MeSH
• hydrolasy MeSH
• plasmin MeSH

Plasmin activity in the tear fluid of the rabbit eye was examined during the wearing of soft contact lenses (SCL) and compared with the occurrence of corneal disturbances assessed in cryostat sections. Plasmin activity was determined with a semiquantitative method using dry punches of filter paper previously soaked in 0.1 M Tris-HCl buffer solution containing mmol/l D-Val-Leu-Lys-FCA (trifluoromethylaminocoumarine), pH 7.2. Punches were applied to the corneal surface for 5 s (tear collection) and incubated in wet chamber. The time of appearance of the bright yellow fluorescence in UV light was recorded and taken as a measure of plasmin activity. For calibration punches soaked in solutions containing plasmin in various concentrations, and processed in the same manner were used. Changes in the cornea were examined histochemically using methods of choice for acid glycosidases, proteases, dehydrogenases, and Na(+)-K(+)-ATPase. SCL with high and low water content were worn in rabbits in 1, 2, 4, 7, 14, 21 and 28 days. Decreased activity of Na(+)-K(+)-ATPase, GGT, and SDH in the corneal endothelium and epithelium were not accompanied by detectable plasmin activity in the tear fluid. Pronounced damage of the corneal epithelium (increased activities of acid glycosidases, acid proteases, LDH, markedly decreased activity of SDH) was accompanied by low concentration of plasmin (0.4-1.0 micrograms/ml) in the tear fluid. Middle activity of plasmin (1.0-2.0 micrograms/ml) was detectable when PMNs were present in the corneal stroma. High plasmin activity (2.0-3.0 micrograms/ml) correlated with corneal ulceration and vascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• aprotinin farmakologie   MeSH
• činčila MeSH
• epitel účinky léků   enzymologie   MeSH
• flurbiprofen farmakologie   MeSH
• histocytochemie MeSH
• inhibitory proteas farmakologie   MeSH
• karbamáty farmakologie   MeSH
• králíci MeSH
• měkké kontaktní čočky škodlivé účinky   MeSH
• oligopeptidy farmakologie   MeSH
• pankreatická elastasa antagonisté a inhibitory   MeSH
• plasmin metabolismus   MeSH
• rohovka enzymologie   metabolismus   MeSH
• slzy účinky léků   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aprotinin MeSH
• elastatinal MeSH Prohlížeč
• flurbiprofen MeSH
• inhibitory proteas MeSH
• karbamáty MeSH
• oligopeptidy MeSH
• pankreatická elastasa MeSH
• plasmin MeSH
• tetrapeptide carbamate MeSH Prohlížeč

Activities of different enzymes (acid glycosidases, phosphatases, Na+ - K+ -dependent ATPase, proteases, dehydrogenases) and acid glycosaminoglycans were studied by histochemical methods in sections of rabbit anterior eye segments after experimental alkali burn and treatment with aprotinin, an inhibitor of plasmin and other serine proteinases. Solutions of sodium hydroxide (0.25-1.0 M) were applied on corneas using 12-mm-diameter plastic tube for 15-60 s. After wiping with cotton and rinsing with tap water aprotinin solutions were applied in saline (in experimental animals) and saline (in control animals) dropwise in 12-h intervals for a month. Within the first two weeks aprotinin was used at a concentration of 5000 IU/ml. During the subsequent two weeks the aprotinin concentration was reduced to 2500 IU/ml. Striking differences in enzyme activities and in the healing between treated and untreated eyes were found. Without aprotinin, ulcers developed in most corneas within 3 weeks and plasmin was regularly demonstrated in tears and in the aqueous. When aprotinin treatment was started within 24 h after the burn, the number of enzymatically active inflammatory cells was significantly lower, not only in the cornea itself but also in the whole anterior eye segment. With aprotinin treatment no ulcerations and no plasmin in tears and the aqueous were observed and the corneas healed within a month. The healing process started from the zone of enzymatically activated corneal cells in the unburned zone at the corneal periphery. In the regenerating epithelium and endothelium high activities of Na+ -K+ -dependent ATPase, gamma-glutamyltransferase, lactate and succinate dehydrogenases appeared very soon.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• alkalická fosfatasa metabolismus   MeSH
• aprotinin terapeutické užití   MeSH
• dipeptidylpeptidasy a tripeptidylpeptidasy metabolismus   MeSH
• gama-glutamyltransferasa metabolismus   MeSH
• glykosidhydrolasy metabolismus   MeSH
• histocytochemie MeSH
• hojení ran MeSH
• hydroxid sodný MeSH
• králíci MeSH
• kyselá fosfatasa metabolismus   MeSH
• L-laktátdehydrogenasa metabolismus   MeSH
• oči enzymologie   MeSH
• popálení oka chemicky indukované   farmakoterapie   enzymologie   MeSH
• sodíko-draslíková ATPasa metabolismus   MeSH
• sukcinátdehydrogenasa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alkalická fosfatasa MeSH
• aprotinin MeSH
• dipeptidylpeptidasy a tripeptidylpeptidasy MeSH
• gama-glutamyltransferasa MeSH
• glykosidhydrolasy MeSH
• hydroxid sodný MeSH
• kyselá fosfatasa MeSH
• L-laktátdehydrogenasa MeSH
• sodíko-draslíková ATPasa MeSH
• sukcinátdehydrogenasa MeSH

The influence of soft contact lenses (SCL) with low (37%, L) and high (65%, H) water content on rabbit corneas was investigated. The lenses were worn continuously for 1, 2, 4, 7, 10, 14, 21 or 28 days. The changes in corneal transparency, hydration and enzyme activities were studied. A slight change in corneal transparency due to higher hydration caused by a decreased activity of Na+-K+-dependent adenosine triphosphatase (Na+-K+-ATPase) in the corneal endothelium is followed by a decrease in the activity of gamma-glutamyl transferase (GGT). Slight morphological disturbances appear within 4 days in animals wearing SCL (L). SCL (H) produce similar changes one week later. Subsequently, the corneal epithelium becomes thinner and changes in the size of corneal endothelial cells are obvious. Disturbances of enzyme activities in cells of all corneal layers are present. In the epithelium highly increased activities of acid glycosidases, acid phosphatase, and dipeptidyl peptidase I and II, in keratocytes decreased activities of alkaline phosphatase and GGT, and in the endothelium decreased activity of Na+-K+-ATPase and GGT were found. These changes are more severe after SCL (L). In this case, inflammatory cells displaying high activities of lysosomal hydrolases appear in the anterior part of the stroma during the 3rd and 4th weeks and local degradation of glycosaminoglycans and proteins takes place. In contrast, after SCL (H) a remarkable thinning of the corneas was observed during extended wear, accompanied by decreased stainability of stromal glycosaminoglycans and highly decreased enzyme activities in keratocytes. The histochemical methods proved very useful in the assessment of lesions caused by a continuous wear of SCL.

• MeSH
• časové faktory MeSH
• endotel patologie   MeSH
• gama-glutamyltransferasa analýza   MeSH
• histocytochemie MeSH
• hypoxie komplikace   MeSH
• králíci MeSH
• měkké kontaktní čočky škodlivé účinky   MeSH
• PEG-DMA hydrogel MeSH
• polyethylenglykoly škodlivé účinky   MeSH
• rohovka metabolismus   patologie   MeSH
• sodíko-draslíková ATPasa analýza   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gama-glutamyltransferasa MeSH
• PEG-DMA hydrogel MeSH
• polyethylenglykoly MeSH
• sodíko-draslíková ATPasa MeSH