We have previously demonstrated specific insulin-like growth factor I (IGF I) messenger RNA (mRNA) transcripts in cultured rat aortic smooth muscle cells (RASM). To define the role of IGF I in the autocrine growth program of vascular smooth muscle cells, we quantitated IGF I mRNA levels in proliferating and quiescent (serum-deprived for 48 hours) RASM. IGF I mRNA levels were markedly decreased ...

At present, the circulating bioactivity of insulin-like growth factor I (IGF-I) is estimated by immunological measurements of IGF-I levels. However, immunoassays ignore the modifying effects of the IGF-binding proteins (IGFBPs) on the interaction between IGF-I and the IGF-I receptor (IGF-IR). Therefore, we developed an IGF-I kinase receptor activation assay (KIRA) based on cells transfected wit...

The process of posttranslational modifications of IGF-II likely has important physiological consequences. In addition to mature IGF-II, glycosylated proIGF-II(156-amino acid peptide) and two glycosylated big IGF-II forms, IGF-II(1-104) and IGF-II(1-87), have been identified in the human circulation. Due to lack of an appropriate methodology, different IGF-II isoforms have not been demonstrated ...

There have been no studies in any vertebrate that have localized insulin-like growth factor (IGF)-I receptors in prolactin (PRL) cells or that have correlated pituitary binding to the potency of IGF-I in regulating both PRL and growth hormone (GH) secretion. We show that IGF-I binds with high affinity and specificity to the pituitary gland of hybrid striped bass (Morone saxatilis x M. chrysops)...

OBJECTIVE IGF-I is a growth factor, which is expressed in virtually all tissues. The circulating IGF-I is however derived mainly from the liver. IGF-I promotes wound healing and its levels are decreased in wounds with low regenerative potential such as diabetic wounds. However, the contribution of circulating IGF-I to wound healing is unknown. Here we investigated the role of systemic IGF-I on ...

The insulin-like growth factor (IGF) is a complex system of peptide hormones (insulin-like growth factors of type 1 and 2, IGF-1 and IGF-2), cell surface receptors (insulin receptor, IR; insulin-like growth factor receptors of type 1 and 2, IGF-R1, IGF-R2) and circulating binding proteins (insulinlike growth factor binding proteins, IGF-BP 1-6). IGF-1 and -2 are mitogens that play a role in reg...

Background and aims: Laron syndrome is a disease that treated by Insulin-like Growth Factor 1 (IGF-1). This protein is a single chain and has three disulfide bonds. People with Laron syndrome have low rates of cancer and diabetes, although they appear to be at increased risk of casual death due to their stature. IGF-1 is synthesized by many tissues and is secreted from liver as an endocrine hor...

A growing body of evidence suggests that an altered level or function of the neurotrophic insulin-like growth factor-1 receptor (IGF-1R), which supports neuronal survival, may underlie neurodegeneration. This study has focused on the expression and function of the IGF-1R in scrapie-infected neuroblastoma cell lines. Our results show that scrapie infection induces a 4-fold increase in the level ...

PURPOSE Insulin-like growth factor-I (IGF-I) is an important mitogen in many types of malignancies. The purpose of this study was to evaluate the role of the IGF system on cell proliferation and cell death in mouse lung cancer cell lines (3LL). MATERIALS AND METHODS Northern analysis was performed in 3LL cells. We evaluated the phosphorylation of IGF-I receptor (IGF-IR) with IGF-I stimulation...