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SummaryMigration of rabbit granulocytes or mononuclear cells from peritoneal exudates through filter membranes has been studied using Boyden's technique for measuring chemotaxis. Migration depends on 1) the cell type, 2) the pore size of the filter, and 3) the physicochemical properties of the filter. For measuring chemotaxis the pore size should be at least 3 μ for granulocytes and 8 μ for mononuclear cells.

The author discusses the applicability of various theories for describing processes in continuous matter and deals in some detail with the entropy-free thermodynamics of irreversible processes, basing his discourse on the work of J. Meixner in this field. Today there are essentially three different phenomenological theories available for describing processes in continuous matter: (1) The classical Thermodynamics of Irreversible Processes (TIP)1. (2) The Non-linear Field-Theories of Mechanics and their thermodynamic extensions (NFT)2. (3) The Entropy-free Thermodynamics of Processes (ETIP)3' . These theories have in common the conservation laws of continuous matter and the laws of thermostatics. They differ essentially in the arguments on which the constitutive equations (CE) are based. Classical TIP starts from a generalized Clausius—Duhem Inequality (CDI) for the well-known (specific) thermostatic entropy s p5+divJ8O (1) The quantity is well defined by the second law of thermodynamics and is a function = s5(u, p) for fluids and a function = s(u, F) for solid systems. Here u means the (specific) internal energy, p... density, Ff1... deformation gradient, substantial time derivative of and J... current of s. In the case of thermodynamic systems without diffusion one has

1. 24-h-fasted rats exhaled 35–37% of i.v. administered loads of labelled glucose, xylitol and fructose, and 20% of a sorbitol load as14CO2 within a period of six hours. 2. Streptozotocin-diabetic rats exhaled under similar conditions only 11–18% of these substrates as14CO2. The rate of glucose oxidation was similar in both groups of animals when a correction for the different glucose pool size was applied. It is concluded that glucose oxidation to14CO2 takes place mainly in tissues which are not sensitive to insulin. 3. Urinary excretion of all substrates was 39–55% of the given dose in diabetic rats. The large difference of urinary carbon-14 between fasted and diabetic rats was due to the excretion of glucose-14C by the diabetic rats. 4. Six hours after the administration of all four substrates, similar amounts of carbon-14 were recovered in serum, serum osazones, liver glycogen and total lipids and diaphragm glycogen within each group of animals. It is concluded that the similarities of the metabolism of all substrates is due to the rapid conversion of the substitute sugars to glucose.

Young male rats metabolize xylitol, sorbitol and fructose with a half-life of 165 seconds. Within 10 min. after the intravenous injection of a load of these substrates more than 70% of the carbon-14 in plasma is present as 14C-glucose. The labelling of plasma glucose from these substrates appears to be insulin-independent. A small percentage of labelled xylitol, sorbitol and fructose is retained by the liver as glycogen and total lipids. In the normal rat, this process appears to be insulin-independent. In the chronic streptozotocin-diabetic rat, insulin acutely enhances glycogen synthesis from all three substrates and reduces their incorporation into total lipids. Once these substrates have been converted to glucose the further storage as muscle glycogen and adipose tissue total lipids is entirely dependent on insulin, both in the normal and in the streptozotocin-diabetic rat. Fructose makes an exception since it is metabolized by adipose tissue independently of insulin. In the light of these results in the rat a re-evaluation of the use of various carbohydrates and polyols in parenteral nutrition of normal and diabetic subjects appears desirable.

Chemotaxis has been defined as a reaction by which the direction of locomotion is determined by chemical substances in the environment (1). Chemotactic attraction of leucocytes has first been described by Leber in 1888 and his findings were immediately integrated into Metchnikoff’s contemporary concept of inflammation. It was postulated that chemotaxis directs mobile phagocytes to the site of injury and thereby promotes efficient phagocytosis and histiolysis (2). For a long time the experimental support for this hypothesis remained rather poor (3). More recent data, however, which have been obtained with a new and more efficient in vitro technique developed by Boyden (4) show a fairly good correlation between in vitro chemotaxis and leucocyte accumulation in vivo.

It is the purpose of this review to provide a survey of some more recent work on chemotaxis of leucocytes. Attention was drawn to the existence of a variety of cytotaxins (chemotactic mediators) and in particular to their cell specificity. The significance of these different cytotaxins for the accumulation of leucocytes in inflammatory sites in vivo is discussed.

A modification of Boyden's method for evaluation of chemotaxis is described. It permits the measurement of chemotactic agents in serum-free medium. Its possible usefulness for the determination of isolated chemotactic mediator(s) is discussed.

Die Untersuchungen zeigen, dass mehrere Zytotaxine im Kaninchenserum vorhanden sein konnen. Zwei davon wirken spezifisch auf Granulozyten und ein anderes spezifisch auf mononukleare Zellen.