Hakan Kocamis

Temporal expression of growth factor genes during myogenesis of satellite cells derived from the biceps femoris and pectoralis major muscles of the chicken

The expression of mRNAs for transforming growth factors (TGF‐β2, myostatin, activin‐B, and follistatin), insulin‐like growth factors (IGF‐I and ‐II), and fibroblast growth factor (basic, bFGF) was investigated in satellite cells derived from chicken pectoralis major (PM) and biceps femoris (BF) muscles in the stages from initiation of proliferation to fusion. These growth factor gene cDNAs were synthesized by reverse transcript ase polymerase chain reaction (RT‐PCR). No myostatin, activin‐B, follistatin or bFGF expression was detected in either cell culture at 0 h. TGF‐β2 mRNA level increased at 48 h (P < 0.01) and remained constant through 144 h in both PM and BF satellite cell cultures. The ontogeny of myostatin gene expression with the exception of a sharp increase in BF culture at 72 h (P < 0.01), was nearly identical in both cell cultures. Activin‐B mRNA level in PM satellite cells was higher than that in BF satellite cells at 72 h and 120 h (P < 0.01). Follistatin mRNA in PM satellite cells was higher than that in BF satellite cells at 24, 96, and 120 h culture (P < 0.01). No IGF‐I gene expression was detected in cell cultures at any time point. IGF‐II gene expression in BF satellite cells declined at 96 h (P < 0.01) and remained reduced until 144 h. bFGF mRNA in both satellite cell cultures increased at 24 h (P < 0.05) and remained at this level in BF satellite cells through 144 h. J. Cell. Physiol. 186:146–152, 2001.

The effects of recombinant human IGF-1 (insulin-like growth factor-1) injection on liver growth in rats.

The purpose of the present study was to evaluate the effects of recombinant human (rh) IGF-1 administration on liver growth of rats. RhIGF-1 (100 ng/kg/day prepared in 0.01 M NaHCO3) was injected (s.c) daily to rats for seven days. Control groups received the same injection procedure with only 0.01 M NaHCO3. One day after the last injection, rats from both control and rhIGF-1 injected groups ( n=5p er group) were euthanized and liver tissue samples were collected (group I). Liver samples from both groups (n = 5 per group/collection day) were collected on week one (group II) and week two (group III) after the last injection. Tissue samples were immediately fixed in Bouins solution and embedded in paraffin. Tissue sections were cut into 5-6 µ thickness and stained with Crossmans triple staining method. RhIGF-1 administration increased the number and the diameter of liver epithelial cells (hepatocytes) which in turn affected the liver growth of rats.