English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

IGF action in vivo is acutely regulated by IGF-binding protein-1 (IGFBP-1) and its phosphorylation state is implicated in modulating these effects. Since IGFs have an important regulatory role in adipocyte function, we investigated the effects of phosphorylated IGFBP-1 (pIGFBP-1) and non-phosphorylated IGFBP-1 (npIGF BP-1) on 3T3-L1 preadipocyte proliferation and adipocyte metabolism. IGFs stimulated clonal expansion of 3T3-L1 cells (IGF-I more potently than IGF-II (EC(50): 30 nM and 50 nM)). npIGFBP-1 inhibited IGF-I (50 nM) clonal expansion at a 5:1 molar ratio (P&lt;0.01), whereas pIGFBP-1 (purified from HepG2 cell medium) abolished clonal expansion at a 1:1 molar ratio (P&lt;0.005). In contrast, IGF-II-induced clonal expansion was inhibited 100% at a 1:1 molar ratio of npIGFBP-1. In mature adipocytes, IGF-I was equipotent with insulin in stimulating glucose uptake (EC(50): 10 nM) and inhibiting isoproterenol-induced lipolysis (EC(50): 15 nM). npIGFBP-1 completely reversed IGF-I effects at a 1:1 molar ratio (P&lt;0.01). In summary, IGFs rather than insulin are potent regulators of clonal expansion in 3T3-L1 preadipocytes. Importantly, IGFs are equipotent with insulin in regulating adipocyte metabolism. IGFBP-1 inhibits IGF effects on preadipocyte proliferation and adipocyte metabolism, with pIGFBP-1 being more potent than npIGFBP-1 at inhibiting mitogenic actions. Since IGFBP-1 is acutely regulated by insulin, this could have important consequences in hyperinsulinaemic and insulin-resistant states.

IGF-binding protein-1 inhibits IGF effects on adipocyte function: implications for insulin-like actions at the adipocyte