Importance of Mucopolysaccharides in the Development of the Protective Hepatotropic Effect of Hypothyrosis

Abstract

Modifications of mucopolysaccharide(MPS) content were investigated in the livers of thyroidectomized, thyroidectomized plus CCl4-treated and in non-thyroid ectomized CCl4-treated rats using histological and histochemical methods .Thyroidectomy seems to decrease the amount of MPS in the liver, inhibiting at the same time depolymerization and accumulation of acid MPS. On CCl4 treatment increased amounts of acid MPS were noted. Hepatotoxic effect was found to be concomitant with increased depolymerization.After thyroidectomy the characteristic damaging effects of CCl4 treatment could not assert themselves, the histological pattern of the livers being similar to that of thyroidectomized. rats.These examinations seem to indicate a parallelism between MPS and changes of hepatoendocrine correlations. The histological examinations confirmed the histochemical results. On the basis of the results obtained the present authors believe that changes occurring in the polymerization, quantity and quality of MPS may contribute to increase the capacity of the liver to inactivate estrogen, and to counteract the hepatotoxic effect of CCl4 treatment in cases of hypothyrosis.From the results of previous investigations, the present authors point out the interrelation between tryptophan and MPS metabolism.The role and importance of mucopolysaccharides (MPS) in various branches of medical research are to-day in the center of interest. Since the first review of Levene1 published in 1925, numerous data have been accumulating on the chemistry, physiology and pathophysiology of mucopolysaccharides. Some authors claimed that these protein-carbohydrate compounds have no specific function whatever and are only products of tissue disintegration. But this does not seem to be acceptable.2.3 It has been demonstrated for example that acid and neutral MPS are essential components of connective tissue fibers,4-6 since the fibers devoid of neutral NIPS are unable to function.7-9 It has been also demonstrated that apart from their role played in formation of supporting tissues MPS participates actively in processes of growth, regeneration, fecundation and multiplication.10 In addi tion, the MPS are involved in certain pathological processes,11-22 in water and salt household10,23 and in certain enzyme activities,10,24 as well as in the interaction of the living organism and microorganisms. [25][26][27][28]