The mode of reaction of interstitial connective tissue with water

Abstract

When water was injected into the subcutaneous tissues of a freshly killed animal, it was observed to accumulate around the point of injection (Ranvier's 'Boule d'cedeme'). Other fluids, such as alcohol, did not localize in this way, but spread evenly and rapidly into the surrounding tissues. These facts suggested a peculiar avidity of the tissue for-water. Examination of the swollen tissue with the dark ground microscope showed separation, without visible alteration, of the collagen fibrils. For this reason, it was considered probable that the water had combined with a substance which lay between the fibrils rather than with the fibrils themselves (Day., 1948). A substance of this kind had been previously described (Day, 1947 a), and Flemming's observation (1876), that, in acid solutions of strength sufficient to cause the collagen fibres to swell, this substance became shrunken, was confirmed.The present investigation is concerned with those changes in the morphology of interstitial connective tissue which took place, in aqueous solutions, as the result of experimental variation of pH and of neutral salt concentration. The study was undertaken with the object of gaining further knowledge of the mode of reaction of this tissue with water with particular regard to the part played by the interfibrillary substance. METHODSThe material studied was the deep fascia immediately covering the ventral aspect of the thigh muscles of the rat. Pieces up to 1 cm. wide were removed from a freshly killed animal. Each was placed at once in at least 20 ml. of the fluid in which it was to be studied. The pH of the fluids was measured electrometrically, with a glass electrode apparatus, at the beginning and at the end of the period of immersion of the tissue. The pH of the fluids was varied by the addition of dilute HCI or NaOH. Where solutions of salts were concerned, the quantity of Na+ or Cl-so added, was so very small in comparison with the concentrations of the salt ions already present that they could be ignored. Usually, the tissue was left in the fluids overnight and at a room temperature between 18 and 200C.The changes which took place were observed with the naked eye and also microscopically using dark ground illuimination. A Leitz 'cardioid' type of condenser was employed in conjunction with a Pointolite illuminant.

The Physiology of the Connective Tissue (Loose Areolar)

“…Evidence has been presented (36, 37), from histological techniques in conjunction with pH changes and dehydration, that the interfibrillar material is membranous in nature and that the collagen bundles are held together by an amorphous cementing substance which is modified by trypsin (34,35). From these characteristics, Day deduced that, in the ground substance, pro tein with an isoelectric point about 4.5 is present which, when modified, -loses its physical properties (38,39,41). An hyaluronidase-sensitive muco polysaccharide, by its macromolecular properties, may act as a "waterproof ing" of the connective tissue (40) which in essence is a fabric of protein fibers.…”

The Role of Connective Tissue in the Filling of Lymphatics

“…Another method by which a membranous arrangement may be shown to obtain in connective tissue depends on the chemical affinities of the interfibrillary substance of which they are largely composed. It has been shown [Day, 1949] that this substance is at least in part composed of a protein having an iso-electric point in the region of pH 4 0. It is to be expected, therefore, that the substance should have some affinity for basic dyes in neutral solution.…”

Growth of Cells in Agitated Fluid Medium

“…The per cent serum and BSS were varied, while the per cent embryo extract was kept constant at 10 per cent. TABLE 3 shows the cell number obtained after three days' growth in 40 per cent, 60 per cent, and 80 serum, each with 10 per cent embryo extract. The probability that the difference found between 40 per cent serum and 60 per cent serum was owing to chance is less than 0.01.…”