论文部分内容阅读
目的：建立同位素稀释技术测定粪中内源性钙和钙的真正吸收率的方法。方法：３２只生长期雄性ＳＤ大鼠肌肉注射４５Ｃａ，每日记录进食量并分别收集粪便和尿样。整个实验期间饲喂含钙（碳酸钙形式）０．４３％的半合成饲料。在４５Ｃａ注射后的第６（１组）、９（２组）、１２（３组）和１５日（４组）各处死一组（８只）动物，分别测定粪便、尿、血浆、肝脏、肾、脾、睾丸、胰、小肠、注射端及非注射端大腿肌肉、脑、皮毛及股骨等组织中４５Ｃａ活性和钙含量，并对粪中排泄的４５Ｃａ活性进行动态观察。结果：４５Ｃａ注射一周后，粪及尿中４５Ｃａ的排出趋于稳定。比较不同组织的比活性、粪４５Ｃａ比活性与组织的比活性之比，选出血浆、肌肉、肝、脾作为参比组织分别计算内源性粪钙，得到几乎一致的结果：内源性粪钙占总粪钙的１６％，钙的真吸收率为８５％。结论：同位素稀释技术可用于测定粪中内源性钙，在肌注４５Ｃａ至少一周后的粪便可用于内源性粪钙的测定，血浆是最适宜的参比组织。
OBJECTIVE: To establish a method for the determination of the true absorbance of endogenous calcium and calcium in manure by isotope dilution technique. Methods: Thirty-two male Sprague-Dawley rats were intramuscularly injected with 45Ca, the daily intake was recorded, and feces and urine samples were collected respectively. Semi-synthetic feed containing 0.43% calcium (calcium carbonate) was fed throughout the experiment. One group (8 animals) were sacrificed at the 6th (1st group), the 9th (2nd group), the 12th (3rd group) and the 15th day (the 4th group) after the 45Ca injection to determine the stool, urine, plasma, 45Ca activity and calcium content in muscle, brain, fur, femur and other tissues of kidney, spleen, testis, pancreas, small intestine, injection end and non-injection end were observed. The 45Ca activity excreted in feces was observed. Results: After 45Ca injection for one week, excretion of 45Ca in feces and urine tended to be stable. Comparing the specific activity of different tissues, the ratio of specific activity of fecal 45Ca to the specific activity of tissue, the endogenous fecal calcium was calculated as plasma, muscle, liver and spleen respectively as reference tissues, and the results were almost identical: endogenous feces Calcium accounted for 16% of the total fecal calcium, calcium, the true absorption rate of 85%. CONCLUSION: Isotope dilution technique can be used to determine endogenous calcium in feces. Excrement can be used for the determination of endogenous fecal calcium at least one week after intramuscular injection of 45Ca. Plasma is the most suitable reference tissue.