一次注射法适宜采血时间的确定

给绝食、强饲无氮日粮 (NFD)、分别以豆粕或棉粕为唯一氮源的CP2 0 %半合成饲粮的蛋青鸡 ,静脉一次注射 3 0 μCi3H Leu/kgBW ,于注射后 5、3 0min、4、2 4、3 6、48h翅静脉采血 ,测定各时间点的去蛋白血浆比放射性强度及 48h内排泄物的比放射性强度。通过定积分分析 ,一次静脉注射法检测内源氨基酸损失量的适宜采血时间为注射3H Leu后 2 0～2 4h。

DETERMINATION OF THE OPTIONAL TIME FOR TAKING BLOOD SAMPLES BY SINGLE INTRAVENOUS INJECTION OF ~3H-LEUCINE

Twenty four young hens(1 5kg of body weight, BW) were randomly divided into 4 groups. Every group was diet free(FAS) or force fed a nitrogen free diet (NFD) or the diet with 20% crude protein in which soybean meal or cotton seed meal was the sole nitrogen source (30g DM/kg BW). 30μCi 3H Leu/kg BW was intravenously injected into all birds just after force fed or on fasting. Venous blood samples were taken at 5, 30min, 4,24,36 and 48h after injection. The excreta during the whole period of 48h after injection was collected. Special radioactivities of non protein plasma at every time point and excreta were measured. The optional time of taking blood samples was 20～24 hours after injected 3H Leu.