Variation of food availability affects male striped hamsters (Cricetulus barabensis) with different levels of metabolic rate

Abstract

In the present study, we examined metabolic, morphological and neurochemical changes in male striped hamsters (Cricetulus barabensis) in response to variations in food availability. Males with low and high levels of metabolic rate (MR: L-MR and H-MR, respectively), defined by their activity MR, were compared. In Experiment 1, 36-h food deprivation was found to significantly decrease MR levels, body fat content, mass of small and large intestines, and leptin gene expression in the white adipose tissues in male hamsters. Interestingly, L-MR males displayed decreased MR during both the day and night phases of circadian cycles, whereas H-MR males only showed a decrease in MR during the day (resting phase). These data indicate that individual differences in physical activity were associated with animals' different metabolic responses to food deprivation. In Experiment 2, both groups of males went through a 4-week fasting and re-feeding (re) paradigm. H-re males showed a persistent high level of MR, with decreased body fat content and a trending decrease in leptin mRNA expression, compared to L-re males. Together, our data indicate that male striped hamsters with different levels of physical activity display altered, adaptive changes in response to variations in food availability. The neurochemical involvement of such adaptive changes needs to be further studied.

Exposure to hot temperatures during lactation stunted offspring growth and decreased the future reproductive performance of female offspring

“…Gross energy intake (GEI), digestive energy intake (DEI) and digestibility were measured between days 13 and 15 of lactation (W21°C-L21°C, n=16; W21°C-L32.5°C, n=14; W32.5°C-L21°C, n=15; W32.5°C-L32.5°C, n=15). As described previously (Grodzinski and Wunder, 1975;Wen et al, 2018aWen et al, , 2018b, a known quantity of food was provided at 16:00 h on day 13, and any uneaten food and orts mixed with the bedding material were collected, along with feces from each animal on day 15. Food and feces were separated manually after drying at 60°C to constant mass.…”

Temperature determines the shift of thermal neutral zone and influences thermogenic capacity in striped hamsters

“…As described previously (Wen et al. 2018a,b), air was pumped at a rate of 1000 mL·min −1 (Calosys Pump, 994620‐AirP‐YP‐VC, TSE, Germany) through a cylindrical sealed Perspex chamber (diameter: 10 cm and length: 35 cm). Air leaving the chamber were dried using a special drier (Air drying Process Control Unit, TSE system, Germany) and directed through an oxygen and carbon dioxide analyzer (Ultramat/Oxymat 6, Siemens, Germany) at a flow rate of 380 mL·min −1 .…”

Neurobiology of motivated behaviors

“…Dr. Eckel and her colleague review the mechanism controlling homeostatic and hedonic eating and the potential role of inflammation in mediating the effects that high-fat diet have on energy metabolism (Butler & Eckel 2018). Dr. Zhao and his colleagues show that striped hamsters ( Cricetulus barabensis ) in their natural environment and particularly in the summer do not store food and feed mainly on plants and are, therefore, on food restriction (Wen et al 2018). Their data show that individual differences in metabolic rates may determine how hamsters will physiologically and behaviorally respond to changes in food availability in their environment.…”