Casotti G
Department of Biology, West Chester University, West Chester, PA 19383, USA.
J Exp Biol. 2001 Mar;204(Pt 6):1201-6. doi: 10.1242/jeb.204.6.1201.
Seasonal variability in kidney morphology of the house sparrow Passer domesticus was examined using light microscopy. Sparrows were captured from the wild in winter, spring, summer and autumn. The kidneys were perfused with half-strength Karnovsky's fixative and processed for light microscopy by embedding in either paraffin wax or JB4 acrylic resin. Absolute volumes of the kidneys, their components (cortex, medulla and blood vessels), components of the nephron (renal corpuscles, proximal tubules, loops of Henle, distal tubules and collecting ducts) and the capillaries surrounding the nephron were quantified using stereology. Tissue processed in paraffin wax had a mean shrinkage of 17.7 % compared with 10.1 % in JB4 resin. Absolute volumes of the kidneys and nephrons were compared statistically between tissue processing methods and among seasons. Absolute volumes of the structures within the kidneys were not significantly different between treatments or among seasons. Within the nephron, the only measured variables to show significant differences were the absolute volumes of the distal tubules and cortical collecting ducts between tissue processing treatments. Thus, kidney morphology was relatively unaffected by changes in season. In addition, the results show that embedding tissue using acrylic resin causes less shrinkage, and it should therefore be the preferred embedding medium for quantitative morphologists.
利用光学显微镜检查了家麻雀肾脏形态的季节性变化。在冬季、春季、夏季和秋季从野外捕获麻雀。用半强度的卡诺夫斯基固定液灌注肾脏，并通过嵌入石蜡或JB4丙烯酸树脂进行光学显微镜处理。使用体视学方法对肾脏及其组成部分（皮质、髓质和血管）、肾单位的组成部分（肾小体、近端小管、亨氏袢、远端小管和集合管）以及围绕肾单位的毛细血管的绝对体积进行了量化。石蜡处理的组织平均收缩率为17.7%，而JB4树脂处理的组织平均收缩率为10.1%。对组织处理方法之间以及不同季节的肾脏和肾单位的绝对体积进行了统计学比较。肾脏内各结构的绝对体积在不同处理或不同季节之间没有显著差异。在肾单位内，唯一显示出显著差异的测量变量是组织处理方法之间远端小管和皮质集合管的绝对体积。因此，肾脏形态相对不受季节变化的影响。此外，结果表明，使用丙烯酸树脂包埋组织导致的收缩较小，因此它应该是定量形态学家首选的包埋介质。
