Effects Of Benefiting-bone Capsule On Levels Of Glutamate,GABA And GABA_BR1 Subunit In Bone Tissue Of Ovariectomized Rats With Osteoporosis

Objective:The research was to observe effects of Benefiting-bone capsule(BBC), a pure Chinese herbal compound preparation, on levels of glutamate(Glu), gamma-aminobutyric acid(GABA) and GABA type B receptor 1 subunit (GABA_BR1) in cells of bone tissue surface of ovariectomized rats with osteoporosis(OP), and to explore some possible esoteric mechanism of BBC treating OP.Methods:1. Sixty 10-month-old Sprague-Dawley(SD) female rats were used. 48 of them were chosen randomly as the model group and made into experimental animal model of osteoporosis with the method of breeding for 12 weeks after bilateral ovariectomy, and the other 12 rats were chosen as the sham-operated group. 12 weeks later the bone mineral density (BMD) of these rats was checked by Dual energy X-ray absorptiometry to assure that the experimental animal model of osteoporosis was replicated successfully.2. 12 weeks later the rats in the model group were divided uniformly into untreated model group, low dose BBC group, middle dose BBC group and high dose BBC group. The rats in the low dose BBC group, middle dose BBC group and high dose BBC group were respectively treated with gastric perfusion of BBC solution that amounted to 1 time, 3 time and 9 time dose of BBC used in clinic adult patients, and those in the sham-operated group and untreated model group received gastric perfusion of normal saline, once a day for 12 weeks. Then glutamate, GABA and GABA_BR1 in cells on bone trabecula surface of distal fermur of rats in every group were checked with immunohistochemistry method. The rank data was compared among groups.3. Statistic software SPSS 13.0 was used and rank sum test was adopted for comparison of rank data among groups. Results:1. 12 weeks after operation the BMD of many bone situses of rats in model group was significantly lower than that of rats in sham-operated group(P＜0.05).2. 24 weeks after operation the expression levels of glutamate and GABA of untreated model group were significantly lower than that of sham-operated group(P＜0.05); that of low dose BBC group, middle dose BBC group and high dose BBC group were significantly higher than that of untreated model group(P＜0.05); that of middle dose BBC group and high dose BBC group were significantly higher than that of sham-operated group and low dose BBC group(P＜0.05); there were not significant differences between sham-operated group and low dose BBC group, and between middle dose BBC group and high dose BBC group (P＞0.05).3. The expression levels of GABA_BR1 of all groups were not significantly different(P＞0.05).Conclusions:1. 10-month-old SD female rats had been made successfully into experimental animal model of osteoporosis by breeding for 12 weeks after bilateral ovariectomy.2. The descent of levels of glutamate and GABA in cells on bone tissue surface may be involved in the abnormality of bone rebuilding and contribute to the morbidity of OP of ovariectomized rats.3. Dose-dependent increasing the levels of glutamate and GABA in cells on bone tissue surface may be the mechanism of BBC treating OP of ovariectomized rats.4. There was not significant change of level of GABA_BR1 in cells on bone tissue surface in the morbidity of OP of ovariectomized rats.