Abstract
Growth of the male external genitalia is primarily regulated by androgens; however, several observations suggest growth hormone (GH) or a GH dependent factor, such as insulin-like growth factor-1 (IGF-1), might also be involved. It is hypothesized that testosterone (T) might induce the synthesis of IGF-1 or IGF-binding protein (IGF-BP) which could affect cell proliferation. This was evaluated by determining the effect of T on thymidine incorporation, cell surface IGF-1 binding, and the production of IGF-1 and IGF-BP by cultured neonatal foreskin fibroblasts. Testosterone significantly increased thymidine incorporation and the production of IGF-1 and IGF-BP (p < 0.05 vs control). However, T significantly decreased the cell surface binding of IGF-1 (p < 0.0001 vs control). To determine whether or not the increase in IGF-1 production was important in mediating the effect of T on thymidine incorporation, cells were incubated with either anti-IGF-1 antibody (anti- IGF-1), anti-IGF-1-receptor antibody (IGF-1-R-Ab), or a non-specific control antibody (NS-Ab). Anti-IGF-1 significantly decreased thymidine incorporation in both control cultures and those containing T. In addition, IGF-1-R-Ab blocked the expected T dependent increase in thymidine incorporation, while NS-Ab had no effect. These in vitro observations suggest both T and IGF-1 affect neonatal foreskin fibroblasts in a complex relationship. In addition, these data suggest T might stimulate foreskin fibroblast proliferation, at least in part, by changing the balance in production and effects of IGF-1 and IGF-BP.
Original language | English (US) |
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Pages (from-to) | 381-388 |
Number of pages | 8 |
Journal | Annals of Clinical and Laboratory Science |
Volume | 25 |
Issue number | 5 |
State | Published - Jan 1 1995 |
Externally published | Yes |
ASJC Scopus subject areas
- Microbiology
- Immunology and Allergy
- Pathology and Forensic Medicine
- Immunology
- Molecular Biology
- Hematology
- Clinical Biochemistry
- Medical Laboratory Technology