Abstract
Purpose:
Diabetes mellitus (DM) is associated with dry eye disease. TRPV-1 are receptors sensitive to hiperosmolarity. The aim of the present work is to investigate the presence of hiperosmolarity in rat models of DM and the expression of TRPV-1 in the lacrimal gland and cornea of control and DM rats.
Methods:
Diabetes mellitus was induced by streptozotocin (60mg/kg)in male wistar rats (6 weeks old). Data were compared with controls ( n = 5/group) after 5 weeks. Body weight, ocular findings, glycemia, tear secretion, tears and systemic osmolarity was evaluated in both groups. Tissues were harvested and TRPV-1 expression measured by western blotting in the lacrimal gland and cornea.
Results:
The body weight was significantly lower in DM group (p=0.0099), Glycemia was 503.3 ± 21.07 mg/dl in DM and 261.5 ± 4.5 mg/dl in control group (p=0.0001), tear secretion was 5.5 ± 1.19 mm in control and 1.25 ± 1.50 mm in DM group, (p=0.0294). Tear osmolarity and systemic osmolarity was significantly higher in DM group (337 ± 17.35 mOsm and 305.5 ± 2.10 mOsm, respectively) compared to control group (284 ± 3.29 mOsm and 328.8 ± 1.65 mOsm, respectively) (p=0.017 and p=0.0001). TRPV-1 expression in cornea was similar in the DM control group (p=0.7904, repectively).
Conclusions:
DM is associated with tear film and systemic hyperosmolarity in rats. TRPV-1 is expressed in cornea of rats and its expression in those tissues is not changed by DM. These findings suggest a mechanism involving TRPV-1 signaling in the DM dry eye disease. Support: CAPES, CNPq, NAP-FTO USP
Keywords: 482 cornea: epithelium •
576 lacrimal gland •
557 inflammation