Abstract

Leptin and adiponectin secreted by the adipose tissue act in conjunction with thyroid hormones. The adiponectin/leptin ratio is a strong biomarker for cardio-metabolic health. The interrelations between the thyroid gland and adipokines are not yet clear. This study investigated whether anti-diabetic drugs, Metformin and Empagliflozin, lead to changes in leptin, adiponectin and their ratio in an animal model of hypothyroidism; and whether the animal model of hyperthyroidism results in changes in adiponectin and leptin levels. Forty-five male Wistar rats were randomly assigned into three groups for 8 weeks: group I (experimental hyperthyroidism), group II (experimental hypothyroidism) and group III (control). Hyperthyroidism was caused by Levothyroxine (300 μg/kg body weight), and hypothyroidism, by 10 mg/kg/day (1 mL/250 g) propylthiouracil in drinking water. Then, group I and II were subdivided into: Metformin treatment (350 mg/kg/per day), Empagliflozin treatment (10 mg/kg/d p.o) and a control group on a chow diet for another four weeks. The rats were sacrificed. Fasting plasma Thyroid Stimulating Hormone, fT3, fT4, leptin and adiponectin were measured by enzyme-linked immunosorbent assay. The adiponectin/leptin ratio was calculated. The results showed higher plasma TSH, fT4 in the hypothyroid group than in the hyperthyroid group. Hypothyroid rats had increased leptin and decreased adiponectin concentration, suggesting disturbed metabolic functions independent of body weight. Both, Metformin and Empagliflozin, reduced adiponectin and leptin levels in our model of hypothyroidism; however, the adiponectin/leptin ratio decreased. This animal model of hypo- and hyperthyroidism is an effective experimental setting to study adipokine hormone variations and pharmacological interventions.

摘要

脂肪组织分泌的瘦素和脂联素与甲状腺激素共同起作用。脂联素/瘦素比例是心血管健康的重要生物标志物。甲状腺与脂肪因子之间的关系尚不清楚。这项研究调查了在甲减的动物模型中，抗糖尿病药物二甲双胍和依帕格列净是否引起瘦素，脂联素及其比例的改变。甲亢的动物模型是否会导致脂联素和瘦素水平的变化。将四十五只雄性Wistar大鼠随机分为三组，每组八周：I组（实验性甲状腺功能亢进），II组（实验性甲状腺功能减退）和III组（对照组）。甲状腺功能亢进症是由左甲状腺素（300μg/ kg体重）和甲状腺功能低下引起的，饮用水中的10mg / kg /天（1 mL / 250 g）丙硫氧嘧啶。然后，将I组和II组细分为：二甲双胍治疗（350 mg / kg / d，每天），Empagliflozin治疗（10 mg / kg / d，每天）和对照组，以普通饮食连续四周。处死大鼠。通过酶联免疫吸附测定法测定空腹血浆甲状腺刺激激素，fT3，fT4，瘦素和脂联素。计算脂联素/瘦素之比。结果显示，甲状腺功能减退组的血浆TSH，fT4高于甲状腺功能亢进组。甲状腺功能低下的大鼠瘦素增加，脂联素浓度降低，表明代谢功能受到干扰，与体重无关。在我们的甲状腺功能减退症模型中，二甲双胍和依帕列净都降低了脂联素和瘦素的水平。然而，脂联素/瘦素的比例下降。