Studies on the Blood Coagulation (II)

Observations on Crawfish Blood Cells by Electron Microscopy and Considerations on their Classification

Abstract

Blood corpuscles of American Crawfish, Cambarus clarkii, were classified into four types, I, II, III and IV, on the basis of electron microscopical studies refering to the observations by May-Giemsa stain. For electron microskopy, blood samples were fixed by one of two combinations of reagents, i. e. glutaraldehyde-osmic acid or formaldehyde-osmic acid. Type I cells corresponded to the so-called explosive cells, which show a number of rapidly growing vacuoles in wet mount slides or in stained smear. In the electron micrographs of the blood samples, successfully fixed before the coagulation process began, the above mentioned vacuolar structure was never been seen, while there were a considerable number of specific granules. The specific granules were made of a tuft of winding filamentous substances, each less than 100Å in diameter, which gave the granules gromerular ippearance. Once the blood coagulation process started, endoplasmic reticula became enormously swollen or ballooned to rupture finally. Those findings in electron micrographs by the author definitely confirmed the characteristic explosion phenomenon of the cells of this type formerly observed by the optical microscopy. Type II cells, mononuclear and spindle shaped, failed to show any characteristic structures. Both type III and IV cells corresponded to those which has a appreciable number of large eosinophil granules by May-Giensa stain. Electron micrograph revealed large polygonal granules in type III and spherical ones of various sizes in type IV. Each of the type III and IV was further subdivided into two types, i. e. III-1,III-2 and IV-1, IV-2, according to the presence (III-1 and IV-1) or absence (III-2 and IV-2) of a small number of granules with gromerular character similar to those in Type I cells. In the electron micrographs of the formaldehyde-osmic-acid fixed material, each of the eosinophil granules had its electron dense center, where bundles of doubled micro-tubules were seen. The outer tubule was about 200 Å and the inner one was less than 100 Å in diameter. Less than fifteen micro-tubules were bundled tightly, composing one tuft. Neither the mononuclears nor the eosinophils were likely to play any part in the process of blood coagulation, because they usually kept their original structure, while the explosion of the type I cells and the coagulation processes were in progress hand in hand.