Physical training improves visceral adipose tissue health by remodelling extracellular matrix in rats with estrogen absence: a gene expression analysis.
Level 5 - mechanism / opinion, no new human data
Animal experiment (rodent model).
PubMed 28884865 · doi:10.1111/iep.12237
What was done
Forty nulliparous female rats were randomized into four groups (n = 10 per group): sham sedentary (Sh-S), sham resistance training (Sh-Rt), ovariectomized sedentary (Ovx-S), and ovariectomized resistance training (Ovx-Rt). Resistance training was performed using a vertical ladder. Investigators evaluated body mass, food intake, adipocyte cross-sectional area in visceral, parametrial, and subcutaneous depots, extracellular matrix (ECM) gene expression (MMP-2, MMP-9, TGF-β, CTGF, VEGF-A, TIMP-1), and gelatinase MMP-2 activity.
What was found
Ovariectomy increased body mass, food intake, and adipocyte area across all three fat depots, alongside upregulation of MMP-2, MMP-9, TGF-β, CTGF, and VEGF-A gene expression and increased MMP-2 activity. Resistance training counteracted these effects, reducing body mass, food intake, and adipocyte size in all depots. At the molecular level, training upregulated TIMP-1, VEGF-A, and MMP-2 gene expression, downregulated MMP-9, TGF-β, and CTGF expression, and decreased MMP-2 activity. Specific numeric values, effect sizes, and p-values were not reported in the abstract.
Why it matters
This study provides mechanistic insight into how resistance exercise may counteract estrogen-deficiency-induced adipose tissue expansion and extracellular matrix remodeling at the transcriptional and enzymatic levels.
Limits
The study is restricted to a rodent ovariectomy model, which does not fully capture the complexity of human postmenopausal physiology. The abstract does not provide exact quantitative values, variance, exercise protocol duration or intensity details, or protein-level quantification beyond MMP-2 activity.
Cited by
- supports Ovariectomized rodents exhibit reduced physical activity, cage hiding, and visceral fat accumulation.