The nature and action of the thromboplastic (zymoplastic) substance of the tissues / by W.H. Howell.
- William Henry Howell
- Date:
- [1912?]
Licence: Public Domain Mark
Credit: The nature and action of the thromboplastic (zymoplastic) substance of the tissues / by W.H. Howell. Source: Wellcome Collection.
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![Reprinted from the American Journal of Physiology. Vol. XXXI. — October 1, 1912.—No. I. THE NATURE AND ACTION OF THE THROMBOPLASTIC COVMOPLEASTIC) SUBSTANCE OF THE TISSUES: By W. H. HOWELL. [From the Physiological Laboratory of the Johns Hopkins University.] T has long been known that the coagulation of blood is hastened by contact with the tissues. This fact has been demonstrated’ by Arthus! and others for the mammalian blood, but the accelerating effect of the tissues is shown most strikingly in the case of those bloods whose normal, so to speak, intrinsic coagulation occurs very slowly. Such bloods are especially the blood of the birds when removed carefully from the blood vessels so as not to come into contact with the tissues, and the so-called peptonized blood of the dog. Bloods of this kind may be made to clot promptly by the addition of saline or aqueous extracts of various tissues, thymus - gland, muscle, brain, testis, etc. The extractible substance or substances in the tissues which facilitate the process of clotting, which indeed under normal conditions are essential to the prompt clotting of the blood, have been designated as zymoplastic (Schmidt) or thromboplastic (Nolf) substances, although other names of a more specific character have been suggested. The explanation of the manner of action of these substances has varied naturally with the views adopted regarding the nature of the processes of coagulation. According to some authors (Pekelharing, Loeb, et al.), they are substances identical with or similar in action to the fibrin ferment (thrombin). According to Arthus, they are substances of an unknown nature which accelerate the 1 ArTHuUS: Journal de physiologie et de pathologie, 1902, iv, p. 281.](https://iiif.wellcomecollection.org/image/b3344108x_0003.jp2/full/800%2C/0/default.jpg)
