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Liver repair ability in rats under constant light, with and without melatonin

Research in animals or cells · Biogerontology · Oct 15, 2026

What this means

Researchers built two scores to track how well rat livers might regrow as the rats aged. The scores looked useful in this test, but they still need checks by other scientists.

Plain-English summary written by an AI model from the abstract. The original is below.

Tested inAnimals
Who it was tested in
Animals or cells
Kind of research
Research in animals or cells

The science

Original title
Quantitative assessment of liver regenerative potential during accelerated aging: regenerative reserve and regenerative status indices.
Authors
Areshidze DA, Kozlova MA, Anurkina AI et al.
Journal
Biogerontology
Published
Oct 15, 2026
Study type
Lab or animal study · indexed as animal research

Abstract

Age-related changes in hepatocyte ploidy, binucleation, proliferative activity, and senescence-associated cell-cycle arrest may jointly influence liver regenerative capacity, but these features are usually evaluated separately. We developed two composite indices and examined their behavior in a long-term rat model of chronic circadian disruption. Male Wistar rats were assigned to control lighting, constant illumination (dark deprivation; DD), or constant illumination with melatonin (DD + melatonin, 10 mg/kg five times weekly) and assessed at 6, 12, 18, and 24 months. The Index of Regenerative Reserve (IRR) was defined as the proportion of binucleated hepatocytes divided by mean hepatocyte ploidy. The Integrated Index of Regenerative Status (IRS) further incorporated Ki-67 (a marker of active cell proliferation) and p21 (a cyclin-dependent kinase inhibitor associated with cell-cycle arrest) as fractional terms: IRS = IRR × (1 + Ki-67)/(1 + p21).In DD animals, IRR declined from 2.00 ± 0.42 at 6 months to 0.386 ± 0.19 at 24 months; the corresponding 24-month IRS was 0.32 ± 0.17. In DD + melatonin animals, 24-month IRR and IRS were 2.285 ± 0.41 and 2.08 ± 0.16, respectively. Exploratory receiver-operating-characteristic analysis yielded areas under the curve of 0.843 for IRR and 0.905 for IRS. These findings support IRR and IRS as experimental composite descriptors of the hepatic regenerative phenotype. External validation and direct functional regeneration assays are required before broader biological or clinical interpretation.

Read it on PubMed ↗

Areshidze DA, Kozlova MA, Anurkina AI et al. Quantitative assessment of liver regenerative potential during accelerated aging: regenerative reserve and regenerative status indices. Biogerontology. 2026. doi:10.1007/s10522-026-10527-9. PMID: 42881261. https://pubmed.ncbi.nlm.nih.gov/42881261/

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