With the increasing severity of global aging, aging-related issues have become the hotspot in the field of health. In recent years, animal aging models have been widely developed and applied, which is of great significance in the study of aging mechanism. Animals with short life span, such as Caenorhabditis Elegans and Drosophila Melanogaster, have natural advantages in the study of aging. Various rat and mouse aging models have been used in aging studies. In recent years, new animal aging models have been developed, such as the African turquoise killifish. The authors reviewed main animal models used in the study of aging, and analyzed the establishment methods, evaluation indexes, advantages and disadvantages of each model in order to provide reference for related research.

Studies have shown that m6A modifying enzymes regulated the expression of related factors by m6A methylation modification,and then participated in the regulation of adipogenesis,adipocyte hypertrophy,adipose tissue browning and thermogenesis.This article reviews the research progress of m6A methylation modification on the regulation of adipose tissue metabolism.

BACKGROUND AND OBJECTIVES: Intense exercise (IE) induced myocardial fibrosis (MF) showed contradictory findings in human studies, making the relationship between IE and the development of MF unclear. This study aims to demonstrate exercise induced MF is associated with cardiac damage, and inflammation is essential to the development of exercise induced MF. METHODS: Sprague-Dawley rats were submitted to daily 60-minutes treadmill exercise sessions at vigorous or moderate intensity, with 8-, 12-, and 16-week durations; time-matched sedentary rats served as controls. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum cardiac troponin I (cTnI) concentration. After completion of the exercise protocol rats were euthanized. Biventricular morphology, ultrastructure, and collagen deposition were then examined. Protein expression of interleukin (IL)-1β and monocyte chemotactic protein (MCP)-1 was evaluated in both ventricles. RESULTS: After IE, right but not left ventricle (LV) MF occurred. Serum cTnI levels increased and right ventricular damage was observed at the ultrastructure level in rats that were subjected to long-term IE. Leukocyte infiltration into the right ventricle (RV) rather than LV was observed after long-term IE. Long-term IE also increased protein expression of pro-inflammation factors including IL-1β and MCP-1 in the RV. CONCLUSIONS: Right ventricular damage induced by long-term IE is pathological and the following inflammatory response is essential to the development of exercise induced MF.
Animals ; Collagen ; Enzyme-Linked Immunosorbent Assay ; Fibrosis ; Heart Injuries ; Heart Ventricles ; Humans ; Inflammation ; Interleukins ; Leukocytes ; Monocytes ; Rats ; Rats, Sprague-Dawley ; Troponin I

BACKGROUND AND OBJECTIVES: Intense exercise (IE) induced myocardial fibrosis (MF) showed contradictory findings in human studies, making the relationship between IE and the development of MF unclear. This study aims to demonstrate exercise induced MF is associated with cardiac damage, and inflammation is essential to the development of exercise induced MF. METHODS: Sprague-Dawley rats were submitted to daily 60-minutes treadmill exercise sessions at vigorous or moderate intensity, with 8-, 12-, and 16-week durations; time-matched sedentary rats served as controls. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum cardiac troponin I (cTnI) concentration. After completion of the exercise protocol rats were euthanized. Biventricular morphology, ultrastructure, and collagen deposition were then examined. Protein expression of interleukin (IL)-1β and monocyte chemotactic protein (MCP)-1 was evaluated in both ventricles. RESULTS: After IE, right but not left ventricle (LV) MF occurred. Serum cTnI levels increased and right ventricular damage was observed at the ultrastructure level in rats that were subjected to long-term IE. Leukocyte infiltration into the right ventricle (RV) rather than LV was observed after long-term IE. Long-term IE also increased protein expression of pro-inflammation factors including IL-1β and MCP-1 in the RV. CONCLUSIONS Right ventricular damage induced by long-term IE is pathological and the following inflammatory response is essential to the development of exercise induced MF.

Objective To investigate the effects of different thermal conditions on the heat acclimatization and physical ability of rats in hot and humid environment .Methods Sixty-four male SD rats were randomly divided into 8 groups:the normal temperature and humidity rest group ( or the NTHR group );the normal temperature and humidity exercise group ( or the NTHE group );the normal temperature and high humidity rest group ( or the NTHHR group ); the normal temperature and high humidity exercise group ( or the NTHHE group);the high temperature and normal humidity rest group (or the HTNHR group); the high temperature and normal hu-midity exercise group ( or the NTNHE group );the high temperature and humidity rest group ( or the HTHR group ) and the high tem-perature and humidity exercise group (or the HTHE group), each consisting of 8 animals.Every day, the rats of the rest groups were left there at rest in the corresponding environment , while the rats of the exercise groups were first left there at rest for an hour , then had exercise at a load of 14 m/min for an hour for a succession of 14 days.Every day, all the rats were weighed both before and after exper-iment, the rate of weight loss was calculated and rectal temperature was taken the moment after the experiment was terminated .At day 16, all the rats had exercise at high temperature (36℃) and high humidity (85%) environment at a load of 28 m/min for 30 minutes. The number of the exhausted rats and exhaust time were recorded during exercise , and at the same time , the levels of rectal temperature were taken the moment after exhaust and when the exercise was terminated .At day 17, the number of rats that died of exhaust was cal-culated and recorded .Results In the course of heat acclimatization , the rate of weight loss at day 4 for all the animals groups except the groups at high temperature/rest began to decrease considerably (P<0.05).The rectal temperature of the animals in the high tem-perature/rest group and the high temperature/exercise group began to drop significantly at day 4(P<0.05).The rectal temperature and weight loss rate of the rats in the 4 exercise groups were significantly higher than those of the 4 rest groups (P<0.05).Furthermore, the rectal temperature of the HTHE group was significantly higher than that of the HTNHE group (P<0.05), however, there was no significant difference in the rate of weight loss , when comparisons were made between the two groups (P>0.05).Following physical exercise at high temperature and high humidity , the rectal temperature and the number of the rats with exhaust in the midst of the exer-cise and the number of deaths the next day in the HTNHE and HTHHE groups were significantly lower than those in the NTNHR and HTHHR groups (P<0.01).However, no significant differences could be seen between the HTNHE group and the HTHHE group (P>0.05).Conclusion Exercises at high temperature/high humidity and high temperature/normal humidity could achieve best heat accli-matization effect .From the standpoint of least effect on body temperature and weight loss , training at high temperature/normal humidity environment is a more appropriate heat acclimatization method .