A decrease in the tear secretion volume in a mouse model with ulcerative colitis.

Dry eye syndrome is known to develop from several systemic inflammatory diseases. Although dry eye may develop due to extraintestinal complications of ulcerative colitis (UC), the pathogenesis is not well-known. This study aimed to investigate whether there was decrease in the tear secretion volume in a mice model with UC; the difference between the control and dextran sodium sulphate (DSS)-treated group was also determined. This study included a mice model with UC induced by the oral administration of 5.0% DSS for 7 days. Following the DSS treatment, the tear volume was measured using the Schirmer's test. The colon and ocular tissues, including the lacrimal gland, were evaluated using histological and protein analyses. Additionally, tumour necrosis factor (TNF)-α and interleukin (IL)-6 in the plasma were determined. Differences between groups (DSS-treated versus control mice) were determined using Student's The tear volume in DSS-treated mice was decreased compared to that in the control mice. Plasma levels of TNF-α and IL-6 in DSS-treated mice was higher than that of control. Morphological change was observed with the invasion of the inflammatory cell in the lacrimal gland of DSS-treated mice. Terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labelling (TUNEL)-positive cells were increased in the lacrimal glands of DSS-treated mice compared with control group. The distribution of aquaporin-5 expressed in the lacrimal gland of DSS-treated mice was decreased compared to that in the control group. These findings suggest that a decrease in the tear volume in UC was associated with a functional decline in the inflamed lacrimal gland. This result therefore provides useful information that could contribute to the development of treatment approaches for dry eye associated with UC.