Comparison of intrinsic exercise capacity and response to acute exercise in ICR (Institute of Cancer Research) mice derived from three different lineages

Dae-Youn Hwang,Dong-Joo Hwang,Young-Suk Jung,Dong-Hun Choi,Kil-Soo Kim,Ki-Chun Kwon,Hyun-Keun Song,Joon-Yong Cho

doi:10.1186/s42826-021-00094-0

Abstract

BackgroundAs a laboratory animal resource, the ICR mouse is commonly used in a variety of research fields. However, information on differences in exercise-related characteristics in ICR mice derived from different lineages and the underlying mechanisms remains to be elucidated. In this study, we investigated the intrinsic exercise capacity and a magnitude of response to acute exercise, and sought to identify mechanisms contributing to difference in Korl:ICR (a novel ICR lineage recently established by the National Institute of Food and Drug Safety Evaluation, Korea) and two commercialized ICR lineages derived from different origins (viz., A:ICR mouse from Orient Bio Com, the United States, and B:ICR mouse from Japan SLC Inc., Japan).ResultsResults showed that despite no significant difference in body weight and weight-proportioned tissue mass of heart and skeletal muscles among groups, the relatively low intrinsic exercise capacity and exaggerated response to acute exercise were identified in B:ICR comparted with Korl:ICR and A:ICR, as reflected by total work and lactate threshold (LT). Also, the mitochondrial efficiency expressed as the complex 1 and complex 1 + 2 respiratory control ratio (RCR) values for cardiac mitochondrial O2 consumption in B:ICR was significantly lower than that in Korl:ICR with higher level of state 2 respiration by glutamate/malate and UCP3 expression in cardiac muscle.ConclusionsTaken together, these results indicate that the intrinsic exercise capacity of ICR mouse varies according to lineages, suggesting the role of cardiac mitochondrial coupling efficiency as a possible mechanism that might contribute to differences in the intrinsic exercise capacity and magnitude of response to exercise.

Highlights

As a laboratory animal resource, the Institute of Cancer Research (ICR) mouse is commonly used in a variety of research fields
Intrinsic exercise capacity based on total work and lactate threshold in different ICR mouse lineages We measured the Total work (TW), and LT, as approximations of exercise capacity (Fig. 1A)
A higher TW to exhaustion was observed in Korl:ICR and A:ICR mice than those in B:ICR mice (Fig. 1B; total 325.5 m; Fig. 1 Identification of the total work and lactate threshold (LT) as direct and indirect indicators of exercise capacity

Summary

Introduction

As a laboratory animal resource, the ICR mouse is commonly used in a variety of research fields. We investigated the intrinsic exercise capacity and a magnitude of response to acute exercise, and sought to identify mechanisms contributing to difference in Korl:ICR (a novel ICR lineage recently established by the National Institute of Food and Drug Safety Evaluation, Korea) and two commercialized ICR lineages derived from different origins (viz., A:ICR mouse from Orient Bio Com, the United States, and B:ICR mouse from Japan SLC Inc., Japan). Among the diverse lineages of rodents supplied by major vendors of laboratory animals, the ICR mouse, developed in 1945 at the Institute of Cancer Research (ICR), is commonly used in the research field of genetics, neurobiology, immunology, and pharmacology (drug efficacy and safety). Information on the difference in intrinsic exercise capacity and response to exercise in rodents derived from different origins and its underlying mechanisms remains to be elucidated

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