Dynamic changes of cytokine in aqueous humor of rabbits after traumatic cataract

Song TANG; Bing DU; Lina HUANG; Lei QIN; Hong WENG

ABSTRACT

BACKGROUND:

Cytokine is a poly-functional and effective regulator factor to regulate growth of multiple cells. Researches suggest that, as an inflammatory medium, cytokines play a key role in inflammatory reaction of eye; however, there are rare studies on dynamic changes after traumatic cataract.

OBJECTIVE:

To investigate the relationship among inflammatory reaction and dynamic changes of interleukin 1 (IL-1),IL-6 and tumor necrosis factor alpha (TNF-α) in aqueous humor of rabbits after extracapsular cataract extraction.

DESIGN:

Randomized controlled animal study.

SETTING:

Shenzhen Municipal Ophthalmology Hospital, Shenzhen Municipal Ophthalmology Center Affiliated to Medical College of Jinan University.MATERIALS The experiment was carried out in Institute of Shenzhen Municipal Ophthalmology Center Affiliated to Medical College of Jinan University from March 2004 to March 2006. Fifteen healthy adult New Zealand rabbits of 30 eyes,general grade, weighting 2.5-3.0 kg, of either gender, were provided by Animal Center of the Second Clinical Medical College of Jinan University [certification SYXK (yue) 2005-006]. Eyes of rabbits were normal before experiment. All rabbits were randomly divided into normal control group, traumatic control group and operative group with 5 in each group and in total of 10 eyes in each group. IL-1, IL-6 and TNF-α kits were provided by Shenzhen Yawei Biotechnology Company Limited.

METHODS:

Rabbits in traumatic control group and operative group were totally anesthetized with intravenous injection of 10% 1 mi/kg urethan, and then, 5# needle was punctured from corneal limbus to anterior chamber to scarify anterior membrane of lens about 5 mm to establish animal models of traumatic cataract of oculus uterque. Rabbits in normal control group were fed normally. After successful modeling, common antibiotic eyedrops was used to clean conjunctival sac of rabbits in traumatic control group and operative group 3 times a day. On the 3rd day of successful modeling, rabbits in operative group were totally anesthetized with intravenous injection of 10% 1 mL/kg urethan, and then, they undertook extracapsular cataract extraction of oculus uterque horizontally intercepting bladder or waterly separating with breakage of anterior bladder membrane, expulsing nucleus of lens, washing lens cortex and suturing incisions. On the operative day and on the 1st, 3rd, 7th and 14th days after operation, inflammatory reaction of anterior chamber in traumatic control group and operative group was measured and 0.2 mL aqueous humor was extracted from rabbits in three groups to count and classify cells; meanwhile, expressed level and dynamic changes of IL-1, IL-6 and TNF-α in cytokines of aqueous humor were measured with double-antibodies ELASA technique.MAIN OUTCOME

MEASURES:

Total numbors of leucocytes and contents of IL-1, IL-6 and TNF-α in aqueous humor of rabbits in three groups after operation.

RESULTS:

① On the 1st, 3rd, 7th and 14th days after operation, numbers of leucocytes were (2.4±0.7)×106/L, (2,2±0.5)×106/L, (2.8±0.8)×106/L and (2.0±0.5)×106/L in aqueous humor; (19.7±7.3)×106/L, (28.1±9.6)×106/L, (14.2±5.6)×106/L and(8.4±3.8)×106/L in traumatic control group; (65.3±14.5)×106/L, (79.8±12.7)×106/L, (21.7±8.2)×106/L and (12.4±4.1)×106/L in operative group. In addition, numbers of leucocytes were more in traumatic control group and operative group than those in normal control group (F =22.5, 27.9, 11.6, 8.4;P＜0.05). ② Within 1-14 days after operation, contents of IL-1, IL-6and TNF-α in aqueous humo were higher in traumatic control group and operative group than those in normal control group (P＜0.05), and there was a significant difference between traumatic control group and operative group (P＜0.05);however, there was no significant difference among three groups on the operative day (P＞0.05). ③ Contents of cytokines reached peak on the 7th day after operation, decreased gradually, and reached the lowest value on the 14th day.Contents in traumatic control group and operative group were higher than those in normal control group (P＜0.05).

CONCLUSION:

The intraocular inflammation after lens extraction is closely related to the dynamic changes of IL-1, IL-6and TNF-α levels in aqueous humor. Cytokine may be one of crucially inflammatory agents in the eyes after traumatic cataract.