Research on histochemical characteristic of kidney in soft-shelled turtle, Trionyx sinesis
中华鳖肾脏的组织化学特性研究

The morphology and histochemical characteristics of nephron in soft-shelled turtle, Trionyx sinesis, were clearly defined by light microscopy and histochemistry. The results showed that the soft-shelled turtle kidney was composed of several lobules, and each lobule of kidney contained the renal capsule and renal parenchyma. The latter could be divided into a medial zone (MZ) and a lateral zone (LZ). LZ was eosinophilic, and was dominated by the presence of proximal tubules and the collecting duct. MZ was weakly eosinophilic, and was characterized by the presence of renal corpuscles, distal tubules, and intermediate segments. Glomerulus was PAS-positive, both succinate dehydrogenase (SDH) showed weakly positive, however, alkaline phosphatase (ALPase), Na+, K+-ATPase and Alcian blue were negative. Podocytes showed acid phosphatase (ACPase) positive. Proximal tubule brush border was eosinophilic, PAS, alkaline phosphatase, acid phosphatase and Na+, K+-ATPase-positive, and succinate dehydrogenase (SDH) was weakly positive in the region. The intermediate segment, distal tubule and collecting duct were weakly eosinophilic, and showed succinate dehydro-genase-positive. The luminal of intermediate segment was a Na+, K+-ATPase weekly positive. Distal tubule cells in lateral showed a PAS-positive, the luminal epithelium showed a AB-positive. The luminal epithelium of collecting duct showed a strong PAS-positive, ACPase positive particles, Alcian Blue (AB)-positive and toluidine blue (TB)-positive particles. Bright and dark cells of Renal tubular epithelial were detected in toluidine blue stain. The results of histochemical reaction and distribution indicated that cell types of renal tubules in soft-shelled turtle were more, and the proximal tubule played a major role in reabsorption original urine, distal tubule and collecting duct had a role in secretion mucus. That was different from the mammals and birds, and other reptiles.