Changes in beta-endorphin neuron numbers and serum hormone levels in the arcuate nucleus of ovariectomized rats undergoing treadmill exercise  

作　　者：Weijie Zhang Xiyi Liu 

机构地区：[1]Sports Institute of Linyi Normal University, Linyi 276005, Shandong Province, China [2]Department of Physiology, Guangdong Medical College, Zhanjiang 524023, Guangdong Province, China

出　　处：《Neural Regeneration Research》2008年第11期1208-1211,共4页中国神经再生研究（英文版）

摘　　要：BACKGROUND： The arcuate nucleus, when damaged in young rats, can lead to pathological changes in adults, such as osteoporosis. Ovariectomized rats suffer from osteoporosis at eight weeks following surgery and the number of β -endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus is significantly decreased. OBJECTIVE： To establish a rat model of osteoporosis using ovariectomy and to explore changes in the number of β-endorphin neurons and to correlate any such change with serum hormone levels in response to exercise or rest. DESIGN, TIME AND SETTING： The completely randomized block design, neural morphology study was performed at the Key Laboratory of Physiology, Guangdong Medical College, China between March 2004 and January 2005. MATERIALS： Sixteen healthy female rats were selected for ovariectomy. METHODS： Following model establishment, rats were assigned to either rest or exercise groups and each rat was housed individually. Rats in the exercise group underwent an exercise regimen using a treadmill. MAIN OUTCOME MEASURES： Eight weeks following exercise, radioimmunoassay was performed to detect serum growth hormone, estrogen and osteocalcin levels. Immunohistochemistry was used to measure changes in the number of β -endorphin neurons in the arcuate nucleus of the hypothalamus. Changes in bone metabolism were assessed using bone histomorphometry. RESULTS： In the exercise group, the β -endorphin immunoreactive neurons were high in number, darkly stained, and the nucleus was not obvious. In the rest group, the β -endorphin immunoreactive neurons were low in number and lightly stained. The number of β-endorphin immunoreactive neurons in the exercise group was higher compared with the rest group （t = 2.83, P 〈 0.05）. Estrogen levels were similar between the rest and exercise groups （P 〉 0.05）. Serum osteocalcin and growth hormone levels were significantly higher in the exercise group compared with the rest group （t = 2.78, 2.32, P 〈 0.05）. Compared with theBACKGROUND： The arcuate nucleus, when damaged in young rats, can lead to pathological changes in adults, such as osteoporosis. Ovariectomized rats suffer from osteoporosis at eight weeks following surgery and the number of β -endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus is significantly decreased. OBJECTIVE： To establish a rat model of osteoporosis using ovariectomy and to explore changes in the number of β-endorphin neurons and to correlate any such change with serum hormone levels in response to exercise or rest. DESIGN, TIME AND SETTING： The completely randomized block design, neural morphology study was performed at the Key Laboratory of Physiology, Guangdong Medical College, China between March 2004 and January 2005. MATERIALS： Sixteen healthy female rats were selected for ovariectomy. METHODS： Following model establishment, rats were assigned to either rest or exercise groups and each rat was housed individually. Rats in the exercise group underwent an exercise regimen using a treadmill. MAIN OUTCOME MEASURES： Eight weeks following exercise, radioimmunoassay was performed to detect serum growth hormone, estrogen and osteocalcin levels. Immunohistochemistry was used to measure changes in the number of β -endorphin neurons in the arcuate nucleus of the hypothalamus. Changes in bone metabolism were assessed using bone histomorphometry. RESULTS： In the exercise group, the β -endorphin immunoreactive neurons were high in number, darkly stained, and the nucleus was not obvious. In the rest group, the β -endorphin immunoreactive neurons were low in number and lightly stained. The number of β-endorphin immunoreactive neurons in the exercise group was higher compared with the rest group （t = 2.83, P 〈 0.05）. Estrogen levels were similar between the rest and exercise groups （P 〉 0.05）. Serum osteocalcin and growth hormone levels were significantly higher in the exercise group compared with the rest group （t = 2.78, 2.32, P 〈 0.05）. Compared with the

关 键 词：EXERCISE arcuate nucleus β-endorphin immunoreactive neurons OVARIECTOMY OSTEOPOROSIS 

分 类 号：R713.6[医药卫生—妇产科学] R68[医药卫生—临床医学]