Hironobu Sunada

IMMUNOHISTOCHEMICAL LOCALIZATION OF TYPE I, II, III, AND IV COLLAGENS IN THE LUNG

Type specific rabbit antibodies to bovine type I, 11, 111, and IV (basement membrane) collagens showing no cross‐reaction with other types of collagen were prepared by cross‐adsorption and diethylamiuoethyl‐cellulose romatography. The antibodies to bovine type I and I11 collagens showed a high cross‐reaction with the corresponding human collagens, but those to type I1 and IV collagens did moderate and no cross‐reactions with human type I1 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 I11 collagens were found to distribute widely in the interstitium of bronchial tree, bronchial

Sodium ion modulates collagen types in human fibrolastic cells in culture

Collagen synthesis in human fibroblasts was increased by the presence of 0.1M excess NaCl in the culture medium. Type analysis of the collagen produced by the cells showed the increase in the ratio of type III collagen to the total collagen. Similar NaCl effects were observed in several cell lines derived from different tissues. Sodium ion but not chlorine ion seems to be essential to the modulation of collagen production by the cells, because addition of CH3COONa induced similar effects but addition of KCl instead of NaCl resulted in specific inhibition of the collagen production.

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.

Reciprocal effects of excess potassium salts in the culture medium on type I and type III collagen synthesis by human skin fibroblasts

By the addition of excess KCl or CH3COOK in the culture medium of human skin fibroblasts, production of non-collagenous proteins and membrane transport of [3H]proline of the cells were activated, but collagen synthesis was not increased. Production of type I collagen was inhibited under these culture conditions but type III collagen synthesis was activated; thus the ratio of type I to type III collagen decreased from 10 to near 1, indicating that the regulation of these two types of collagen is independent in human skin fibroblasts.