Endocytosed LDL and β-VLDL follow different intracellular pathways in rat liver

Gudmundsen, Ola; Nenseter, Marit S.; Berg, Trond

doi:10.1016/0005-2760(93)90050-j

Cited by 1 publication

(1 citation statement)

References 29 publications

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“…Also in keeping with previous studies (2), we found a close correlation between IGF-II and total, LDL, and HDL cholesterol. The significance of the IGF-II/cholesterol relationship is unknown, although similarities in clearance pathways between the ␤-very low density lipoprotein (␤-VLDL) receptor and the mannose-6-phosphate receptor may suggest a possible mechanism (27). Insulin levels were similar in all three ethnic groups, with C-peptide being lower in African-Caribbeans than in Europeans or Pakistanis.…”

Section: Igfbp-1 and Macrovascular Diseasementioning

confidence: 99%

Low Circulating Levels of Insulin-Like Growth Factor Binding Protein-1 (IGFBP-1) Are Closely Associated With the Presence of Macrovascular Disease and Hypertension in Type 2 Diabetes

et al. 2002

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The IGF system is increasingly implicated in the development of cardiovascular disease. The effects of circulating IGFs on the vasculature are largely modulated by IGFBPs, which control their access to cell-surface IGF receptors. IGFBP-1 has been proposed as the acute regulator of IGF bioavailability because of its metabolic regulation by glucoregulatory hormones. Posttranslational phosphorylation of IGFBP-1 significantly increases its affinity for IGF-I and therefore represents a further mechanism for controlling IGF bioavailability. We have therefore examined the IGF system and IGFBP-1 phosphorylation status, using specifically developed immunoassays, in a cohort of 160 extensively characterized type 2 diabetic subjects on two occasions 12 months apart. Total IGFBP-1 (tIGFBP-1), which is predominantly highly phosphorylated, was significantly lower in subjects with known macrovascular disease triglycerides, and nonesterified fatty acids. In contrast, levels of nonphosphorylated and lesser-phosphorylated IGFBP-1 (lpIGFBP-1) were unrelated to macrovascular disease or hypertension but did correlate positively with fasting glucose concentration ( ‫؍‬ 0.350, P < 0.01). tIGFBP-1 concentrations were higher in subjects treated with insulin alone (n ‫؍‬ 29) than for any other group. This effect persisted after adjustment of tIGFBP-1 levels for BMI, C-peptide, age, and sex (F ‫؍‬ 6.5, P < 0.001, ‫؍‬ ؊0.46). Such an effect was not apparent for lpIGFBP-1. We conclude that low circulating levels of hpIGFBP-1 are closely correlated with macrovascular disease and hypertension in type 2 diabetes, whereas lpIGFBP-1 isoforms are associated with glycemic control, suggesting a dual role for IGFBP-1 in the regulation of IGF actions in type 2 diabetes. Our data suggest that high circulating concentrations of highly phosphorylated IGFBP-1 may protect against the development of hypertension and cardiovascular disease by reducing the mitogenic potential of IGFs on the vasculature.

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Section: Igfbp-1 and Macrovascular Diseasementioning

confidence: 99%