Isolation and characterization of proteoglycan derived from human placenta and its biological activities

Modification of plasma glycosaminoglycans in long distance runners

BACKGROUND

It is well documented that exercise reduces the risk of thromboembolic disease, possibly by increasing the plasma concentration of anticoagulant-antithrombotic compounds.

OBJECTIVES

As plasma glycosaminoglycans (GAGs) play a role in the anticoagulant-antithrombotic potential of plasma, to examine the concentration and profile of these compounds in well trained, long distance runners and sedentary subjects.

METHODS

Plasma GAGs were measured in 10 male, long distance runners and 10 sedentary counterparts before and after ergometric tests. GAGs were extracted, purified, and identified by electrophoretic and enzymatic methods, and measured as hexosamine.

RESULTS

Plasma GAGs found in sedentary subjects were slow migrating heparan sulphates I and II, keratan sulphate I, and chondroitin 4-6-sulphate. Those found in trained athletes were slow migrating heparan sulphate I, chondroitin 4-6-sulphate (or keratan sulphate I), and fast migrating heparan sulphate. Total plasma concentrations of GAGs were higher in athletes than in sedentary subjects at rest. In sedentary subjects, plasma GAGs did not change after cycle ergometric exercise at 80% of their anaerobic threshold. However, the appearance of a novel band of heparan sulphate migrating faster than fast migrating heparan sulphate was observed in athletes after exercise.

CONCLUSIONS

Exercise changes the amount and profile of plasma GAGs; these changes may play a role in protecting subjects who practise aerobic sports against developing cardiovascular disease.

Anticoagulant activity of sulfoalkyl derivatives of curdlan

Curdlan is a natural beta-1,3-glucan produced by Agrobacterium biovar 1. In this study, the anticoagulant activity of sulfoalkyl derivatives of curdlan was investigated by carrying out activated partial thromboplastin time (APTT) assay and compared with that of o-sulfonated curdlan. Approximately 100-fold higher concentration of o-sulfonated curdlan than heparin was required to obtain the same level of the clotting time. Anticoagulant activity of curdlan derivatives was dependent on the degree of sulfation in prolonging the clotting time. However, the chain length of the substituent did not play a role in prolonging the clotting time. The curdlan derivatives enhanced thrombin inhibition by mediating through antithrombin III. The inhibition of thrombin by o-sulfonated curdlan was found to be approximately 10-fold weaker than that by heparin.