Level D· Scientific groundwork from lab and animal studiesAnimal StudyPubMed

The expression of insulin-like growth factor-1 during adipogenesis in vivo: effect of thyroxine.

Kim HS., Richardson RL., Hausman GJ.

Animal Study, published in Gen Comp Endocrinol (1998) — summary generated from the PubMed abstract.

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Level D· Scientific groundwork from lab and animal studiesEvidence level of this study

Evidence from laboratory and animal studies provides groundwork for understanding mechanisms and potential before human studies continue.

  • Level A · Stronger Clinical Evidence
  • Level B · Emerging clinical evidence with positive signals
  • Level C · Early human research exploring benefits
  • Level D · Scientific groundwork from lab and animal studies
  • Emerging · Emerging topic under active research
Read the A–D evidence level guide

This page is generated from the PubMed record. The Thai description is an automated summary of bibliographic fields and the abstract, not a full translation, and is not medical advice.

Study type
Animal Study
Journal
Gen Comp Endocrinol (1998)
Country
United States
Reported sample size
—
Source database
PubMed
PMID
9748401
DOI
10.1006/gcen.1998.7126

Abstract (original English)

The expression of insulin-like growth factor-1 (IGF-1) was examined in subcutaneous (SQ) adipose tissue from 105-day pig fetuses by ribonuclease protection assays and in situ hybridization using a porcine IGF-1 riboprobe. Fetuses were hypophysectomized (hypox) at 70 days of gestation and at 90 days thyroxine (T4) pellets were implanted into some of the hypox fetuses. Fetuses were removed and SQ tissues collected on day 105 of gestation. RNase protection assays followed by scanning laser densitometry revealed that IGF-1 mRNA in SQ adipose tissue in hypox fetuses was significantly decreased to 19.8 +/- 1.2% of control values. T4 treatment increased the expression of IGF-1 by 174 +/- 26.6% of values for hypox fetuses. Using in situ hybridization we showed that fetal hypophysectomy reduced and T4 treatment increased expression of IGF-1 mRNA in the outer SQ adipose tissue layer (P < 0.05). However, T4 treatment after hypox did not influence IGF-1 expression in the inner SQ layer (P > 0.05). IGF-1 was expressed around capillaries, in small fat cells, and in fibroblasts in loose and dense connective tissue. Large fat cells, however, did not express IGF-1. Collectively, we concluded that (1) IGF-1 mRNA was decreased after hypox and increased by T4 treatment in SQ tissue of 105-day fetuses; (2) The expression of the IGF-1 gene was more sensitive to T4 treatment after hypox in outer SQ t

What this study does not prove

  • • This study does not prove SVF is an approved treatment or a replacement for standard care.
  • • This is preclinical work; animal or laboratory results cannot be applied to humans.

Evidence level

Evidence from laboratory and animal studies provides groundwork for understanding mechanisms and potential before human studies continue.

How we grade evidence
Adipose TissueAnimalsFemaleGene ExpressionGestational AgeHypophysectomyIn Situ HybridizationInsulin-Like Growth Factor IPregnancyRNA, Messenger

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