Demonstration of collagen type conversion in culture supernatants from human chondrocytes by an inhibition ELISA
Zlabinger, G.J.; Menzel, J.E.; Steffen, C.
Clinical and Experimental Rheumatology 6(4): 361-367
1988
ISSN/ISBN: 0392-856X PMID: 3229025 Document Number: 323505
Culture supernatants from monolayer cultures of human chondrocytes were tested for the presence of collagen type I and type II during subpassaging using an inhibition Elisa. The sensitivity of the Elisa was 404 +/- 50 ng/ml (mean +/- SEM) for the determination of type I collagen and 112 +/- 16 ng/ml for type II collagen. Whereas using immunofluorescence techniques, type II collagen was observed in human chondrocytes cultured under monolayer conditions only up to the first subpassage (1), in culture supernatants from human chondrocytes type II collagen could be found up to the fourth subpassage. Type I collagen was detectable in supernatants from the beginning of primary cultures and was present up to the tenth subpassage in increasing concentrations. Variations in the amount of collagen present in the culture supernatants seemed in part to be due to different growth characteristics of the chondrocytes. Cell shape was not associated with the release of a particular collagen type. In summary, the collagen inhibition Elisa appears to be equivalent to biochemical methods with regard to sensitivity and specificity. Investigations on influencing the switch in collagen production in human chondrocytes may benefit from the use of both techniques described.