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Biomedical subjects

H Sunada

Publications and source records attributed to H Sunada.

At least 55 records · Page 3Linked to original sources
PubMed1981

Dual effects of type II collagen on the degradation of type I collagen by tadpole collagenase.

Kinetic analysis of the degradation of mixtures of type I and type II collagens by tadpole collagenase was performed, using [14C]glycine-labeled type I collagen and [3H]acetylated type II collagen as substrates. The degradation rate of type I collagen was decreased in the initial stage of the reaction, then further slowed down giving a constant rate independent of both the amounts of enzyme and type II collagen. The effect of type II collagen on the degradation of type I collagen is two-fold. First, competitive inhibition manifested only in the initial stage of the reaction due to higher (about 4-fold) affinity of type II collagen for the enzyme than type I collagen. Second, interference in step(s) following the formation of enzyme-substrate complex.

Animals↗
PubMed1981

Immunohistochemical localization of type I, II, III, and IV collagens in the lung.

Type specific rabbit antibodies to bovine type I, II, III, and IV (basement membrane) collagens showing no cross-reaction with other types of collagen were prepared by cross-adsorption and diethylaminoethyl-cellulose chromatography. The antibodies to bovine type I and III collagens showed a high cross-reaction with the corresponding human collagens, but those to type II and IV collagens did moderate and no cross-reactions with human type II and IV collagens, respectively. By using these antibodies, tissue distribution of various types of collagen in normal bovine lung was examined by indirect immunofluorescence microscopy. both type I and III collagens were found to distribute widely in the interstitium of bronchial tree, bronchial lamina propria and of interlobules as well as alveolar nipples and adventitia of pulmonary arteries. Type II collagen was located only in bronchial cartilage. The tissues mainly stained for type III collagen were the alveolar interstitium (also stained faintly for type I collagen) and the intima and media of the arteries. Type IV collagen was located in a membranous fashion in alveolar septa and bronchial smooth muscles and subepithelial layers as well as capillaries and the intima and media of arteries.

Animals↗
PubMed1980

A rapid micro-assay method for gelatinolytic activity using tritium-labeled heat-denatured polymeric collagen as a substrate and its application to the detection of enzymes involved in collagen metabolism.

A rapid micro-assay method for gelatinolytic activitiy has been developed using 3H-labeled heat-denatured polymeric collagen (gelatin) as a substrate to investigate enzymes involved in the post-collagenase catabolism of collagen. The method is based on the incubation of gelatin with enzyme followed by determination of the enzyme digestion products soluble in 67% dioxane. It is sensitive enough to detect microgram levels of gelatin fragments, and can be employed over wide ranges of pH and ionic strength. By applying the method to an embryonic chick skin culture system, three gelatinolytic enzyme fractions which showed high, limited and no caseinolytic activities were demonstrated to be separable by gel chromatography.

Acetic Anhydrides↗