A.L. Copley

Comparative observations on adherence and consistency of various blood systems in living and artificial capillaries

The apparent viscosity of blood, plasma and serum, as measured in theScott Blair (frame) capillary viscometer, is found to be appreciably lower in fibrin coated capillaries than in glass capillaries. This phenomenon, which is probably associated with an enhanced sigma effect, is found in blood of man, cow, rabbit and horse.

Capillary flow and wall adherence of bovine blood, plasma and serum in contact with glass and fibrin surfaces

Summary1.Procedures and treatment of data for the measurement of the apparent viscosity and wall adherence of bovine blood, plasma and serum in contact with glass and fibrin surfaces in capillaries are described.2.Blood and, in many cases, plasma and serum, exhibited non-Newtonian behaviour on both glass and fibrin surfaces.3.The flow behaviour could be represented conveniently in linear form by plotting the square root of the rate of shear against the square root of the stress at the wall.4.Blood on fibrin surfaces exhibited the sigma effect, i. e. anomalies with changes in capillary dimension, more markedly than on glass surfaces.5.The apparent viscosity and wall adherence on fibrin surfaces was always less than on glass.6.Experiments were done on blood from ten cows. Heparin was used as anticoagulant. No consistent differences were observed between blood from the mammary and jugular veins, nor between that from lactating and non-lactating animals.Zusammenfassung1.Apparate und Behandlungsart der Proben zur Messung der scheinbaren Viskosität und der Wandhaftung von Rinderblut, Plasma und Serum in Kontakt mit Glas und Fibrinoberflächen in Kapillaren wird beschrieben.2.Blut und meist auch Plasma und Serum zeigen in beiden Fällen, sowohl in Kontakt mit Glaswand und Fibrinwand nicht-Newtonsches Verhalten.2.Das Fließverhalten kann in üblicher Weise linear dargestellt werden, wenn man die Quadratwurzel aus der Schergeschwindigkeit gegen die Quadratwurzel aus der Scherspannung an der Wand aufträgt.4.Blut an Fibrinflächen zeigt den Sigmaeffekt — das sind Anomalien bei Veränderung der Kapillardimension — ausgeprägter als an Glasflächen.5.Die scheinbare Viskosität und die Wandhaftung an Fibrinflächen ist stets geringer als die an Glas.6.Die Versuche wurden mit Blut von 10 Kühen durchgeführt. Als Antikoagulant wurde Heparin verwendet. Es wurden keine systematischen Unterschiede zwischen Blut aus Brust- und Halsvenen, ebensowenig wie zwischen solchem von milchgebenden und nichtmilchgebenden Tieren gefunden.

Comparative observations on adherence and consistency of various blood systems in living and artificial capillaries. II: Additional note to a previous paper

SummaryThe apparent viscosity of blood, plasma and serum, as measured in theScott Blair (frame) capillary viscometer, is found to be appreciably lower in fibrin coated capillaries than in glass capillaries. This phenomenon, which is probably associated with an enhanced sigma effect, is found in blood of man, cow, rabbit and horse.Silicone treated surfaces, though not so reliable, show a possibly significant but very much smaller reduction in apparent viscosity.Since, during life, fibrin in some form probably covers the inner lining of blood vessel walls, the phenomenon here described must constitute an important factor in aiding blood circulation.

Symposium on Rheological Properties of Erythrocytes in Health and Disease: Organized jointly by the International Society of Biorheology and the International Society of Hematology on 6 August 1970, during the XIII International Congress of Hematology, Munich, Germany

THE SYMPOSIUM had as original moderators Dr. Leopold Dintenfass, Sydney, Australia and Dr. H. Schmid-Schoenbein, Munich, Germany. It was organized with the consent of the President of The International Society of Biorheology, A. L. Copley, who also as Co-Editorin-Chief of Biorheology, attended the meeting at Munich. Since Dr. Dintenfass could not participate in the symposium, it was chaired by H. Schmid-Schoenbein. In order to expedite the publication of papers presented at this symposium, the Editors-inChief made arrangements with the publisher, Pergamon Press Ltd. to have a number of these papers published in subsequent issues of Biorheology. An editorial experiment was made by the appointment of Guest Editors whose task was to aid A. L. Copley as Co-Editor-in-Chief, in appraising the presented papers, each to be done by two referees. The maintenance of the high standards, set by the editorial policy of Biorheology, and rapid publication could thus be secured. The difference from our usual editorial procedure lies in a new practice in not keeping the anonymity of the referee, but making it possible for the guest editor to communicate directly with the authors in recommending to them revisions or changes in the manuscript, as the referees require. The final decision of acceptance of the paper still rested with the Editors-in-Chief. We should like to thank the Guest Editors, Professors Shu Chien, Hemorheology Laboratory, College of Physicians and Surgeons, Columbia University, New York, N.Y., Dr. Joseph F. Gross, Rand Corporation, Santa Monica, California, and Professor P. L. La CeI1e, Department of Biophysics, University of Rochester, Rochester, N.Y., as well as other referees they consulted, for their cooperation in this editorial experiment. The following communication is a symposium paper.