An investigation of total and 35S-labeled mucopolysaccharides in intestinal wall kidney of cattle, sheep and swine

Mucopolysaccharides (MPS) occur in the ground substance of connective tissue and have been isolated and identified from many diverse types of tissue. Because MPS have recently been shown to be associated with numerous physiological and pathological processes, interest has tremendously increased in their metabolic synthesis, functions and degradation. As MPS have the ability to bind water and cations, they are essential for the maintenance of an extracellular homeostatic environment. Regulation of water reabsorption in the kidney, lubricant for joints, regulation of cell permeability and involvement in the calcification processes of bone formation are other metabolic processes in which MPS have been demonstrated to participate. Abnormal MPS tissue concentrations and/or excretory patterns have been reported for individuals exhibiting atherosclerosis, gastric ulcers, arthritis, Marfan's disease and Hurler's syndrome.

Previous studies by Bell et al. (1964) which revealed that yearling cattle absorb and excrete ⁹⁹Mo very differently from growing swine cultivated our interest in MPS. Because of the strong electro negative charge due to active sulfate and carboxyl radicals which exist on the acid-MPS molecule, it was speculated that they could facilitate absorption, excretion and reabsorption of cations such as molybdenum] and, thus, be involved in the mechanisms responsible for dissimilarity in utilization of radioactive Mo among species.

Research by Boström (1952) strongly justifies the utilization of ³⁵S isotopic labeling techniques to investigate chondroitin sulfuric acid metabolism in vivo. His results indicated clearly that ³⁵S retained by rats was firmly incorporated by articular cartilage as a part of the chondroitin sulfate structure and that the greatest rate of labeled SO₄⁼ fixation occurred in tissue most rapidly synthesizing MPS.

The principle objective of this investigation was to establish and compare the concentration of total and sulfated MPS in intestine and kidney of cattle, sheep and swine. In order to accomplish the primary goal, it was necessary to determine; (1) accurate hexosamine, protein, mineral and sulfur analysis procedures; (2) a reliable method for tissue homogenization; (3) a procedure for separation and isolation of MPS from protein; (1;) an estimation of MPS biosynthesis rate; and (3) plasma SO₄⁼ and ³⁵S levels.