Effects of IGF-I on the synthesis and processing of glycosaminoglycan in cultured chick chondrocytes

in European Journal of Endocrinology
Restricted access

Abstract. We have studied the effect of the somatomedin IGF-I on stimulation of synthesis of DNA, RNA, protein, and glycosaminoglycan in chick chondrocytes. Stimulation of RNA and protein synthesis was rapid, occurring within 10 min after addition of IGF-I. Stimulation of sulphation required a lag time of about 2 h, whether chains were initiated on native protein core or on the artificial acceptor 4-methyl-umbelliferyl-β-D-xyloside. DNA synthesis was not stimulated until after 10 h of exposure to IGF-I. Investigation of the rate of processing of proteoglycan core protein after pulselabelling chondrocytes with 35SO4 yielded data which were best described by a biexponential function. IGF-I had no effect on the t½ of the initial phase (16.44 min in the absence of IGF-I and 20.38 min in the presence of IGF-I). However, addition of IGF-I resulted in a decrease in the t½ of the terminal phase from 122.58 to 55.44 min, which may reflect an increase in synthesis in the enzymes necessary for polymerization and sulphation of proteoglycan.

 

     European Society of Endocrinology

Related Articles

Article Information

Metrics

All Time Past Year Past 30 Days
Abstract Views 99 99 5
Full Text Views 69 37 0
PDF Downloads 48 20 0

Altmetrics

Cited By

PubMed

Google Scholar