Insulin increases the steady state level of alpha-1(I) procollagen mRNA in the osteoblast-rich segment of fetal rat calvaria.
Insulin at 3-100 nM increased the steady state level of alpha-1(I) procollagen mRNA and stimulated collagen synthesis in the osteoblast-rich segment of central bone from 21-day-old fetal rat calvaria. The increases in the level of procollagen mRNA and the rate of collagen synthesis were observed 18 h after the addition of insulin to the cultures. The removal of insulin from calvaria incubated for 24 h with 3 nM insulin caused collagen synthesis and the level of alpha-1(I) procollagen mRNA to return to control values within 5 h. Adding insulin back to calvaria withdrawn from insulin treatment for 3 h did not rescue the decay in collagen synthesis or the level of alpha-1(I) procollagen mRNA. Insulin increased the steady state levels of alpha-1(I) procollagen mRNA in the presence of the RNA synthesis inhibitor actinomycin-D. Our data suggest that in fetal rat bone, one mechanism by which insulin increases the steady state level of alpha-1(I) procollagen mRNA may be by altering its stability.
Craig
R G
RG
Department of BioStructure and Function, University of Connecticut Health Center, Farmington 06032.
Rowe
D W
DW
Petersen
D N
DN
Kream
B E
BE
D000818:Animals; D015152:Blotting, Northern; D001842:Bone and Bones / Q000378:metabolism; D003094:Collagen / Q000096:biosynthesis; D005333:Fetus; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D011347:Procollagen / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D011347:Procollagen; D012333:RNA, Messenger; D003094:Collagen