【摘要】 <正> 狗骨髓造血细胞的功能和形态与人的很相似,又便于返复多次进行形态学观察,故近些年来该种动物多用于放射生物学和生理学等方面的研究。 由于对其正常骨髓造血细胞的增殖、分化和成熟过程尚感研究不够,且结果也不一致(Alpen,1959;Maloney,1958;Lala,1966;Maloncy,1963),而这一工作又是进一步深入研究放射生物学及造血系统疾病,如白血病等的重要基础理论研究之一,因而有必要对其骨髓造血细胞的细胞周期、成熟过程,中性粒细胞向周围血释放及其在周围血中的寿命进行观察。更多还原

【Abstract】 Two hybrid female (native) dogs,weighing 13,12.5 kg respectively,9-10 months old,were used.With 3H-TdR (S.A.34 Ci/mM,1 mCi/ml),4mCi dissolved in 1,000 ml normal saline,continuous labelling was adopted and persisted for 6 hours intravenously in each dog.Bone marrow was drawn 12 times from humerus,tibia,femur and sacrum in both sides alternatively at one or two hour intervals 1-20 hours after starting intravenous drip,and then bone marrow smears were made.Peripheral blood was drawn from the limb veins 46 times at two hour intervals 40- 130 hr after starting infusion of 3H-TdB,and then blood smears were made.Autoradiography was performed in bone marrow and blood smears with No.4 nuclear emulsion.LI.MI and average number of silver grains per labelled cell were counted in granu-locytic and erythrocytic systems separately in bone marrow smears.The time of first appearance and the time of peak of labelled neutrophils and the half-reducing time (T1/2) of them were observed and calculated in the blood smears.At the same time,the mean grain count of the labelled neutrophils was calculated in order to get the half-reducing time.This is one way to obtain the cell generation time.Prom the present study the following results have been obtained:1.The duration of every phase in the cell cycle in both erythroeytic and neutro-philgranulocytic systems,including cell generation time,is the same.2.The duration in which the mean grain count in labelled cells reached the maximum (14.0 and 11.7 in granulocytie (G) and erythrocytic (E) systems respectively) was 8 hours.That means Ts=8 hrs.3.The duration in which MI reached the maximum (79.5% and 84.5% in G and E series respectively) was 8 hrs.That means TG2+1/2Tm=8 hrs.4.The duration in which LI reached the maximum (62.5% and 70% in G and E respectively) was 8 hrs.That means TG1+TG2+Tm=8 hrs.5.The first appearance of labelled neutrophils in peripheral blood was at 74 hrs after starting injection of 3H-TdR intravenously.They reached the maximum (23%) during the next 18 hrs.We do not deem it necessary for the duration of continuous labelling to persist longer than Ts or as long as or more than one cycle time (Te) as some authors suggested.Several hours were sufficient to get the correct figures of the duration of every phase in cell cycle,although the curve could not keep the peak in a high plateau and the peak figures of LI,MI and mean grain count could not reach the highest level as in the condition in which the duration of continuous labelling persisted for a longer time,but in this way radionuclide could be saved,especially for the unknown Ts or Tc cell lines.更多还原