OBJECTIVE:

To explore the mechanism of endocannabinoids system (ECS) in glucose metabolism of rats with chronic intermittent hypoxia (CIH).

METHODS:

According to random permutation table and experiment time, a total of 48 Wistar rats were randomly divided into 6 groups of 4/6-week control (filling with compressed air with 21% oxygen), 4/6-week CIH (CIH exposure for 8 hours per day) and 4/6-week CIH plus rimonabant group [an intraperitoneal injection of CB1 receptor antagonist rimonabant into liver (1 mg×kg(-1)×d(-1)) before CIH exposure] (n = 8 each). The levels of fasting plasma glucose, serum insulin, serum C-peptide and the expression of CB1 receptor in liver were detected after 4/6 weeks to evaluate the effects of CIH on the indices of glucose metabolism.

RESULTS:

The levels of the following indices in 4/6-week CIH group were significantly higher than those in 4/6-week control group: fasting plasma glucose (8.91 ± 0.40), (10.61 ± 0.36) vs (6.48 ± 0.23), (6.51 ± 0.25) mmol/L; serum insulin (16.72 ± 3.76), (20.25 ± 3.64) vs (9.02 ± 2.05), (9.19 ± 2.35) U/L; serum C-peptide (3.53 ± 0.26), (5.23 ± 0.29) vs (1.37 ± 0.26), (1.41 ± 0.41) µg/L; the expression of CB1 receptor in liver (0.290 ± 0.026), (0.342 ± 0.030) vs (0.214 ± 0.023), (0.221 ± 0.026) (all P < 0.05). Notably 6-week CIH group was significantly higher than 4-week CIH group (P < 0.05). And the above indices in 4/6-week CIH plus rimonabant group were significantly lower than others (both P < 0.05). The level of CB1 was significantly positively correlated with the levels of fasting plasma glucose, serum insulin and serum C-peptide (r = 0.856, 0.758, 0.827, all P < 0.05).

CONCLUSION:

ECS may contribute to abnormal glucose metabolism caused by CIH.