家蚕蛾溶茧酶分泌器官及蛾吐出液的研究

家蚕蛾溶茧酶可能来源于下颚、嗉囊和中肠,嗉囊是否具有分泌溶茧酶的能力至今缺乏直接的证据。分别用光学显微镜和透射电镜观察了家蚕蛾下颚、嗉囊和中肠的组织结构,发现嗉囊不具备分泌器官的形态特征,是由薄的膜围成的囊状结构,没有观察到分泌细胞及其分泌物;而下颚和中肠具有分泌细胞,存在大量的分泌物质。对蛾吐出液进行酶活性检测,发现蛾吐出液除具有酯酶活力外,还具有纤溶酶活力。分别对下颚、嗉囊和中肠的组织蛋白作酯酶活力和纤溶酶活力测定,发现嗉囊组织蛋白不具有这两种酶活力,而下颚和中肠的组织蛋白具有较强的酯酶和纤溶酶活力。以上实验结果表明:家蚕蛾溶茧酶的来源不是嗉囊,溶茧酶可能来源于下颚和中肠。

Studies on Secretory Organs of Cocoonase and Silkmoth-vomiting Fluid of Silkworm, Bombyx mori

The origin of cocoonase of silkmoth, Bombyx mori was likely midgut, maxilla, or craw. However, it was absent of direct evidences whether the craw could secret cocoonase . In this paper, morphology analysis on maxilla, craw, and midgut was carried out by light microscopy and transmitting electron microscopy. Results showed that the craw had not those morphologic characteristics of secretory organ, and it was only a bursa structure enclosed by a thin membrane. No secretory cells and secretions were observed in the slice of craw tissue. However, tissues of maxilla and midgut were different from that of craw, and a mass of secretory epithelium and secrtions was found in their tissue slice. The silkmoth-vomiting fluid and protein concentration, esterase activity, and fibrinolytic activity were assayed. Results indicated that the silkmoth-vomiting fluid had not only the esterase activity with BAEE as the substrate, but also a strong fibrinolytic activity. Tissue proteins of maxilla, craw, and midgut were prepared, and their esterase activities and fibrinolytic activities were assayed. Results showed that the tissue protein of craw had neither the esterase activity nor the fibrinolytic activity, whereas those of midgut and maxilla distinctly exhibited esterase and fibrinolytic activities. It was concluded that the craw of silkmoth, did not secret cocoonase, and the possible origin of cocoonase was maxilla and midgut.