红景天苷对慢性重复悬尾应激动物的保护作用

目的:研究红景天苷(salidroside)对慢性重复悬尾应激模型(repeated tail-suspension test,R-TST)小鼠的保护作用。方法:昆明种小鼠50只,随机分为5组,即对照组、应激组、红景天苷高(60 mg.kg-1)、中(30 mg.kg-1)、低剂量组(15 mg.kg-1)。采用重复悬尾应激模型,重复悬吊应激11 d,每天应激1次,每次2 h,并每隔3 d增加1 h,每次应激前30 min ig给予相应剂量的红景天苷或生理盐水,并于末次应激结束30 min后眼眶取血,用RIA测定血清中睾酮含量。摘取脾脏、胸腺、肾上腺和睾丸,称重并计算脏器指数。取肾上腺和睾丸用4%多聚甲醛固定并制作组织切片,HE染色,显微镜下观察形态学变化。结果:应激后小鼠体重增长程度明显受抑,质量增加幅度仅为对照组的27%;肾上腺指数上升,为对照组的164%;脾脏指数下降为对照组的70%;肾上腺皮质肥厚,髓质萎缩甚至消失。应激组小鼠血浆睾酮水平显著低于对照组(P<0.01)。应激前30min给予低剂量红景天苷可逆转应激导致的体重增加减缓,降低肾上腺指数,脾脏指数增加;肾上腺皮质肥厚及髓质萎缩等病理症状减轻,睾酮恢复至正常水平。但中剂量组和高剂量红景天苷组上述作用不显著。结论:低剂量红景天苷可显著改善应激小鼠体重增加减缓、肾上腺指数升高、脾脏指数下降、肾上腺皮质肥厚、髓质萎缩和结构层次模糊等,且能显著抑制重复悬尾应激所引起的睾酮水平低下并使其恢复正常,提示红景天苷可能通过改善应激所致的睾酮水平降低及维持肾上腺的正常结构和正常生理功能发挥抗应激作用。

Preventive Effect of Salidroside on Stressed Mice Induced by Repeated Tail Suspension Test

Objective: To study the effect of salidroside on the stressed mice induced by repeated tail-suspension test(R-TST). Method: Fifty Kunming mice were randomly divided into five groups,including control group,stressed group, high-dose salidroside group(ig.60 mg ·kg^-1),middle-dose salidroside group(ig.30 mg ·kg^-1),low-dose salidroside group(ig.15 mg ·kg^-1). Repeated tail suspension test model was adopted in this experiment. All groups were stressed once a day for 11 days and two hours daily,the stress time was progressively increased one hour in every three days. Each group was administered with appropriate dose of salidroside or saline 30 min before the stress, the blood samples were collected from the orbit 30 min after the stress. RIA was used to determined the contents of testosterone in serum. The spleen, thymus, adrenal gland and testis were removed and the organ indexes were calculated after weighing. Adrenal gland and testes were fixed with 4% paraformaldehyde and tissue sections prepared, stained with HE, morphological changes were observed under a microscope. Result: After the stress, body weight gain was suppressed significantly for the stressed mice, and the weight gain was only 27% of controls. The adrenal gland index was increased to 164%,spleen index were reduced to 70%,comparing with the control group. Along with adrenal index increase, adrenal hypertrophy, medulla atrophy or even disappeared. And the testosterone level in plasma in mice of the stressed groupwas significantly lowered compared with that of the control group(P<0.01). Giving low dosage of salidroside 30 min before the stress could reverse the slow weight gain caused by stress, reduce adrenal index, relieve the pathological syndrome, such as adrenal hypertrophy and medullary atrophy, and make the testosterone recovered to normal level. However, the similar effects were not found in the mice of middle dose salidroside group and high dose salidroside group. Conclusion: The low-dose salidroside can significantly improve the following problems in the stressed mice: suppressed weight gain, the increased adrenal gland index, adrenal cortical hypertrophy, medulla atrophy and blurred microscopic structure and the low testosterone level. It indicates that salidroside may perform the anti-stress function by means of improving the decreased testosterone level caused by stress and maintaining the normal tissues structure as well as the physiological function of adrenal gland. And high dosage salidroside may have adverse effects.