Sara Schiller

Effect of the thyroid gland on metabolism of acid mucopolysaccharides in skin

In skin of hypothyroid rats, the concentration of hyaluronic acid is increased whereas that of chondroitinsulfuric acid is decreased. These changes are prevented or reversed toward normal by the administration of thyroxine. n nThe effects of hypothyroidism on mucopolysaccharide metabolim appear to be the result of a deficiency of thyroid hormone rather than an excess of circulating thyrotropic hormone.

Influence of AGTH and Cortisone upon Alteration in Capillary Permeability Induced by Hyaluronidase in Rats.

Summary Intravenous administration of 2000 units of partially purified testicular hyaluronidase in rats induced an increased rate of disappearance of Evans blue, a decreased concentration of serum protein, and an increased hematocrit. These manifestations of an increased capillary permeability due to the action of the enzyme preparation were largely inhibited by 5 days pretreatment with subcutaneous administration (5 mg per day) of either ACTH or cortisone acetate. A minimum of 24 to 48 hours of pretreatment with cortisone acetate was required for a discernible inhibition of the hyaluronidase effect. The evidence suggests an intermediate step between cortisone acetate and its action on connective tissue.

The isolation of chrondroitinsulfuric acid from normal human plasma

Abstract Two uronic acid-containing components have been demonstrated in a globulin fractional of normal human plasma by zone electrophoresis. The slower migrating fraction appears to be a mixture containing uronic acid, hexosamines and ester sulfate. The faster migrating fraction behavces in all respects like the chondroitsinsulfuric acid-A isolated from cartilage.

Mucopolysaccharides of the estrogen-stimulated chick oviduct

Abstract Hyaluronic acid, heparin monosulfuric acid and a mixture of chondroitinsulfuric acid-A and -B have been isolated from the oviducts of stilbestrol-injected chicks.

Mucopolysaccharides in relation to growth and thyroid hormones.

Abstract It may be stated that homeostasis of acid mucopolysaccharides occurs if the requirements of the connective tissues for the hormones are supplied. The participation of insulin in the maintenance of normal levels and normal turnover of acid mucopolysaccharides in skin has been described in a previous publication [28]. The requirement for thyroxine was documented in the present communication by demonstrating that its administration restored the defects in mucopolysaccharide metabolism observed in the hypothyroid animal. The decreased turnover of chondroitinsulfuric acid in hypophysectomized rats was effectively reversed by injection of growth hormone. However, the abnormally high concentration of hyaluronic acid was increased further by this treatment. Evidently, administration of growth hormone alone did not create a favorable endocrine environment in the hypophysectomized animal for the restoration of hyaluronic acid metabolism to normal. Although no direct experimental evidence has been presented, it is suggested that maintenance of normal concentrations of hyaluronic acid depends upon an adequate supply of both growth hormone and thyroxine. Taurog et al. [42] have demonstrated that secretion of thyroid hormones is reduced by more than 90 per cent in the hypophysectomized rat. Since hypothyroidism is a conspicuous manifestation of pituitary deficiency, it was not unexpected to find that the alterations in mucopolysaccharide metabolism were similar in both conditions. These studies demonstrate undeniably an influence of hormones on acid mucopolysaccharide metabolism. However, they reveal no unanimity of hormone-enzyme relationships on the biosynthetic or degradative processes involved. In the diabetic rat and in the animal receiving cortisone, the metabolism of both mucopolysaccharides is depressed suggesting a common fundamental defect in the early stages of synthesis. On the other hand, the differential effects of growth hormone and thyroxine on hyaluronic acid and chondroitinsulfuric acid metabolism leads one to conclude that these hormones exert their effects on later stages of synthesis or on degradative pathways.

MUCOPOLYSACCHARIDES OF NORMAL MAST CELLS

Unlike other acidic mucopolysaccharides localized characteristically in the amorphous ground substance of connective tissues, heparin appears to be an intracellular material associated with the granules of mast cells. Many aspects of the structure of heparin have yet to be elucidated. The compound is a heterologous anionic polymer consisting of uronic acid and hexosamine moieties, which presumably alternate to form a disaccharide repeating unit. The uronic acid appears to be a mixture of g l u c u r ~ n i c ~ * ~ and L-iduronic acids;? the amino sugar is glucosamine. The uronosyl linkage has been reported by Nomink et aLR to be 1 + 4, although Cifonelli and Dorfman5 found mainly 1 + 6 with varying amounts of 1 + 4. The hexosaminidic linkage is 1+ 4.9.10 Heparin is a positively rotating substance, and the glycosyl linkages are, therefore, assumed to be a. Biologically active heparin contains, per disaccharide unit, approximately 2% sulfate groups, one of which is attached by sulfamic linkage to the amino group of the hexosamine. According to Laurent,ll the anticoagulant activity of heparin varies with molecular weight.

Acid mucopolysaccharides in aortic tissue of the dog

Thoracic and abdominal aortas from dogs were analyzed for their mucopolysaccharide content by a modification of existing methods. Acid mucopolysaccharides represented approx. 0.7% of the dry weight. The major components were chondroitinsulfuric acid A and C, with lesser amounts of heparitin sulfate and negligible amounts of hyaluronic acid and chondroitinsulfuric acid B.

Evidence that hyaluronidase is not the factor in testicular extract causing increased vascular permeability.

Summary and Conclusions The intravenous or local administration of relatively crude bull testis extract is capable of causing increased vascular permeability in rats. Purification of the hyaluronidase component of this extract results in loss of its capacity to induce increased vascular permeability. The purified hyaluronidase appears to retain its spreading activity.

Isolation of Chondroitinsulfuric Acid from the Cock's Comb.∗

Summary 1. Hyaluronic acid (HA) and chondroitinsulfuric acid (CSA) were isolated from the combs of roosters in a ratio of 15 to 1. 2. The CSA fraction from combs appears to be similar to that isolated from rabbit skin.