Zajicek G, Arber N
H.H. Humphrey Center for Experimental Medicine and Cancer Research, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Cell Prolif. 1991 Jul;24(4):375-82. doi: 10.1111/j.1365-2184.1991.tb01166.x.
Twenty-five male young adult random bred rats, weighing 250-300 g, were injected with 18.5 kBq/g body weight tritiated thymidine (specific activity 185 GBq/mM). The rats were then killed in groups of five, at the following times: 1 h and 14, 30, 60 and 120 days. The kidneys were processed histologically and dipped into liquid emulsion, exposed for 3 weeks and developed. Kinetic measurements were restricted to juxta-medullary glomeruli, their adjacent convoluted tubules and medullary tubuli. All other nephrons were ignored. The medullary pole of the juxta-medullary glomerulus served as reference point for all measurements and was referred to as the origin. The distance of a labelled cell from the origin was measured with an eye-piece micrometer and expressed in terms of two units: distance (microns) and cell location, defined as the number of cells separating a labelled cell from origin. Since only medullary nephrons were considered, these measurements represent distances directed toward the papilla. One hour after labelling, most cells were in the vicinity of the juxta-medullary glomerulus, not further than 800 microns from the origin in the direction of the papilla. During the following days labelled cells advanced toward the papilla at a daily velocity of 13.8 microns, covering 1.1 locations/day. Kinetically, the juxta-medullary nephron is a two-compartment cell renewal system. Its compartments, the progenitor (P) and the functional (Q), cover locations 0-80 and 81-150, respectively. The first feeds the second with cells. Morphologically, the progenitor compartment includes proximal and distal convoluted epithelia and a part of thick straight tubules. Other nephron portions belong to the Q-compartment. It is assumed that the nephrocyte is a part of a cell stream directed toward the papilla, which probably also includes stroma and vasculature.
选用25只体重在250 - 300克之间的随机繁殖雄性成年大鼠，按每克体重18.5千贝克勒尔的剂量注射氚标记胸腺嘧啶核苷（比活度为185吉贝克勒尔/毫摩尔）。随后将大鼠按每组5只进行处死，处死时间分别为：注射后1小时以及14、30、60和120天。取出肾脏进行组织学处理，浸入液体乳剂中，曝光3周后显影。动力学测量仅限于近髓肾小体、其相邻的曲小管和髓质小管。所有其他肾单位均被忽略。近髓肾小体的髓质极作为所有测量的参考点，称为原点。用目镜测微计测量标记细胞到原点的距离，并用两个单位表示：距离（微米）和细胞位置，细胞位置定义为从标记细胞到原点之间间隔的细胞数。由于仅考虑髓质肾单位，这些测量代表指向乳头的距离。标记后1小时，大多数细胞位于近髓肾小体附近，在指向乳头的方向上距离原点不超过800微米。在接下来的几天里，标记细胞以每天13.8微米的速度向乳头推进，每天覆盖1.1个细胞位置。从动力学角度看，近髓肾单位是一个双区室细胞更新系统。其区室，即祖细胞区室（P）和功能区室（Q），分别覆盖位置0 - 80和81 - 150。第一个区室向第二个区室输送细胞。从形态学上看，祖细胞区室包括近端和远端曲上皮以及一部分直的厚壁小管。肾单位的其他部分属于Q区室。据推测，肾细胞是朝向乳头的细胞流的一部分，该细胞流可能还包括基质和脉管系统。
