Yunge L, Ballak M, Beuzeron J, Lacasse J, Cantin M
Can J Physiol Pharmacol. 1980 Dec;58(12):1463-76. doi: 10.1139/y80-221.
The ultrastructural cytochemical reactivity, renin activity, and cathepsin D activity of atria and ventricle of the bullfrog have been assessed. The specific granules (A, B, and D) were found to be argentaphobic when ultrathin sections of Araldite-embedded atria and ventricle were stained according to the periodic acid-thiocarbohydrazide-silver proteinate technique of Thiery. The entire core of the specific granules was moderated positive after ultrathin sections of glutaraldehyde-fixed, glycol methacrylate embedded atria and ventricle were stained by phosphotungstic acid at a low pH. A similar reaction was shown by the cell coat, intercalated discs, residual bodies (C granules), and Z discs as well as by a very small portion of the Golgi complex. Incubation of ultrathin sections of atria and ventricule fixed only in glutaraldehyde and embedded in glycol methacrylate with either pronase or trypsin resulted in selective digestion of specific granules and Z discs and, to a much lesser degree, of the cell coat. As cathepsin D activity and renin activity were present in both atria and ventricle, the generation of angiotensin I by these cardiocytes might have been due to either enzyme. Nevertheless, because of the glycoprotein nature of specific granules and of the endocrinelike ultrastructure of atrial and ventricular cardiocytes in the frog, the present results raise the possibility that specific granules may contain renin.
已对牛蛙心房和心室的超微结构细胞化学反应性、肾素活性和组织蛋白酶D活性进行了评估。当根据蒂埃里的高碘酸 - 硫代碳酰肼 - 银蛋白技术对用阿拉迪特包埋的心房和心室超薄切片进行染色时，发现特异性颗粒（A、B和D）对银盐无嗜性。在用低pH值的磷钨酸对戊二醛固定、甲基丙烯酸乙二醇酯包埋的心房和心室超薄切片进行染色后，特异性颗粒的整个核心呈中度阳性。细胞被膜、闰盘、残余体（C颗粒）和Z线以及高尔基体的一小部分也显示出类似反应。仅用戊二醛固定并嵌入甲基丙烯酸乙二醇酯的心房和心室超薄切片用链霉蛋白酶或胰蛋白酶孵育，导致特异性颗粒和Z线选择性消化，对细胞被膜的消化程度要小得多。由于心房和心室中均存在组织蛋白酶D活性和肾素活性，这些心肌细胞生成血管紧张素I可能是由于这两种酶中的任何一种。然而，由于特异性颗粒的糖蛋白性质以及青蛙心房和心室心肌细胞的类内分泌超微结构，目前的结果增加了特异性颗粒可能含有肾素的可能性。
