Experimental Study of Osteoporosis

[研究目的]实验研究吸收不良、卵巢切除、低钙饮食、糖尿病等因素对骨质疏松发生的影响。[材料与方法]成年比格犬10只，行胰腺十二指肠切除术，造成吸收不良。其中一半采用Child‘s术式重建，其余采用改良方法重建。存活6个月的犬5只，其中2只采用Child‘s手术，另2只采用改良方法，经静脉注射两次四环素后处死。对未脱钙的第3腰椎切片进行组织形态计量学评价。7~8月龄Wistar退役大鼠为持续危险因素，包括卵巢切除、低钙饮食、注射链脲佐菌素诱发的糖尿病。它们要么是单独装载的，要么是与一两个一起装载的。低钙饮食含钙6.0 mg/100g。链脲佐菌素的剂量为30 mg/kg，糖尿病多见于高血糖而不是…超过300 mg/dl。以假手术组大鼠为对照。四环素标记后3个月或6个月处死动物。[结果与讨论]所有犬体重下降0.3~5 kg，均出现脂肪吸收障碍和糖耐量减退。除1只Child‘s术狗外，其余犬的平均骨体积均无明显下降。与对照组相比，与骨形成相关的参数，包括类骨质表面的范围和四环素标记，都受到了抑制。这种骨形成障碍最终会导致骨丢失。在实验的3个月时，所有的大鼠都同时承受了单一因素和其中一种或两种因素的联合作用，骨体积明显减少。6个月时骨体积的减少更为明显，尤其是在糖尿病持续的大鼠。综合危险因素对骨量丢失的影响较单一因素更为显著。糖尿病大鼠在实验3个月时的骨形成率尤其受到抑制，这主要是因为基质形成受损。较少

[Purpose of the study] The effect of risk factors of developing osteoporosis including malabsorption, ovariectomy, low calcium diet, and diabetes was experimentally evaluated.[Materials and Methods] Malabsorption was induced by pancreatoduodenectomy in 10 adult beagles. Half of them were reconstructed by Child's procedure, and the remaining by modified one. Five dogs survived for 6 months, two of them operated by Child's procedure, and the others by modified method, were killed after giving tetracycline twice intravenously. Undecalcified cut sections of 3rd lumbar spine were evaluated histomorphometrically.Wistar-retired rats aging 7 to 8 months were sustained risk factors consisting of ovariectomy, low calcium diet, diabetes induced by streptozotocin injection. They were loaded either alone or in combination with one or two. Low calcium diet contains 6.0mg calcium/100g. Streptozotocin was given intraperitoneally at dose of 30mg/kg, and diabetes was detected by hyperglycemia more than … More 300mg/dl. Sham-operated rats were served as controls. They were sacrificed at 3 or 6 months of experiment after tetracycline labeling. Undecalcified ground sections of the proximal tibia, stained with Villanueva method, were histomorphometrically evaluated with Cosmozone 1S (Nikon).[Results and discussion] All dogs lost their weight by 0.3 to 5kg, and they all sustained malabsorption of fat and lost their tolerance to glucose. Mean value of bone volume did not show significant decrease in pancreatodudenectomized dogs, except for one operated by Child's procedure. Parameters relating to bone formation including an extent of osteoid surface and tetracycline labeling were depressed compared with controls. This impaired bone formation would eventually bring about bone loss.All rats sustained both single factor and in combination with one or two lost their bone volume significantly at 3 months of experiment. Decrease of bone volume at 6 months was more apparent, particularly in diabetes-sustaind rats. The effect of combination of risk factors on bone loss was more dominant compared with that of single factor. Bone formation rate at 3 months of experiment was depressed in diabetes rats in particular, mostly because of impaired matrix formation. Less