Effects of iodine excess on serum thyrotropin-releasing hormone levels and type 2 deiodinase in the hypothalamus of Wistar rats.

Iodine is an important element in thyroid hormone biosynthesis. Thyroid function is regulated by the hypothalamic-pituitary-thyroid axis. Excessive iodine leads to elevated thyroid-stimulating hormone (TSH) levels, but the mechanism is not yet clear. Type 2 deiodinase (Dio2) is a Se-containing protease that plays a vital role in thyroid function. The purpose of this study was to explore the role of hypothalamus Dio2 in regulating TSH increase caused by excessive iodine and to determine the effects of iodine excess on thyrotropin-releasing hormone (TRH) levels. Male Wistar rats were randomised into five groups and administered different iodine dosages (folds of physiological dose): normal iodine, 3-fold iodine, 6-fold iodine, 10-fold iodine and 50-fold iodine. Rats were euthanised at 4, 8, 12 or 24 weeks after iodine administration. Serum TRH, TSH, total thyroxine (TT4) and total triiodothyronine (TT3) were determined. Hypothalamus tissues were frozen and sectioned to evaluate the expression of Dio2, Dio2 activity and monocarboxylate transporter 8 (MCT8). Prolonged high iodine intake significantly increased TSH expression (P < 0·05) but did not affect TT3 and TT4 levels. Prolonged high iodine intake decreased serum TRH levels in the hypothalamus (P < 0·05). Dio2 expression and activity in the hypothalamus exhibited an increasing trend compared at each time point with increasing iodine intake (P < 0·05). Hypothalamic MCT8 expression was increased in rats with prolonged high iodine intake (P < 0·05). These results indicate that iodine excess affects the levels of Dio2, TRH and MCT8 in the hypothalamus.

[Facial nerve function index evaluation on deviation of the mouth in intractable facial palsy treated with sticking needle and traction method on three points of the mouth].

OBJECTIVE: To probe into the effective acupuncture technique for deviation of the mouth in intractable facial palsy. METHODS: One hundred and one cases of intractable facial palsy were randomly divided into an observation group (48 cases) and a control group (53 cases). Cuanzhu (BL 2), Sibai (ST 2), Jiache (ST 6) and Qianzheng (Extra) on the affected side were punctured in two groups. Additionally, three acupoints of the mouth were supplemented, named Dicang (ST 4), Kouheliao (LI 19) and Jiachengjiang (Extra) were added, and the sticking needle and traction method was adopted on them in observation group. the routine needling technique was applied in control group. The treatment was given once a day and 10-day treatment made one session. The changes in facial nerve function index (FNFI) were observed in 2 sessions of treatment. RESULTS: After treatment, FNFI in two groups increased significantly (both P < 0.01), but the improvement in observation group was better than that in control group (P < 0.01). In observation group, the basic recovery rate of FNFI was 87.5% (42/48), which was higher than that (67.9%, 36/53) in control group (P < 0.05). CONCLUSION: The sticking needle and traction method o three points is the quite effective approach in the treatment of deviation of the mouth in intractable facial palsy.