Changes in Body Composition of Old Rats at Different Time Points After Dexamethasone Administration

Abstract

Background: Aging leads to changes in skeletal muscle quantity and quality and is accompanied with increase in body mass and fat mass, whereas fat-free mass either decreases or remains unchanged. The body composition of rodents has been an important factor for clinical trials in the laboratory. Glucocorticoids such as dexamethasone are widely used in clinical medicine, but may induce myopathy, characterized by muscle weakness, atrophy, and fatigue. In animals treated with glucocorticoids, a dose-dependent reduction of body weight has been observed. This weight loss is usually followed by muscle atrophy and a reduction of several muscle proteins, contributing to impaired muscle function. This study was designed to describe changes in body composition and BMC of 22-month-old rats during 10- and 20-day recovery period after 10-day dexamethasone administration. Method: Data on body mass, lean body mass, fat mass and bone mineral content of the rats were obtained with dual energy X-ray absorptiometry scan. Result: Significant reduction in body mass, lean body mass, fat mass and fast-twitch muscle mass was observed after dexamethasone treatment. Body mass, fat mass and fast-twitch muscle mass stayed decreased during 20 days after terminating the hormone administration; lean body mass reached the preadministration level after 20-day recovery period. There were no significant changes in bone mineral density during the recovery period. Dexamethasone treatment gradually reduced hindlimb grip strength that also stayed decreased during the 20-day recovery period. Conclusion: his study demonstrated that a 10-day period of overexprosure to glycocorticoids induced longlasting changes in old rats’ body composition and these values did not attain the baseline level even after 20-day recovery period.

A single intra-articular dose of vitamin D analog calcipotriol alleviates synovitis without adverse effects in rats

“…Side effects of dexamethasone may vary depending on the dose, exposure time and age of rats. Overexposure of dexamethasone in 22-month-old rats for ten days caused long lasting changes in body composition such as reduction of lean body mass and bone mineral content [36]. We speculate that dexamethasone, with water solubility of 0.1 mg/ml compared with 0.6 μg/ml of calcipotriol, might have been absorbed from the synovial space into circulation faster than calcipotriol, which remained in crystals for a longer period of time.…”

Beneficial Effect of H2S-Releasing Molecules in an In Vitro Model of Sarcopenia: Relevance of Glucoraphanin

“…In fact, a strong association between aging and sarcopenia development exists also following dexamethasone treatment [ 42 ]. Indeed, an excess of dexamethasone markedly reduces muscle strength and physical activity in animals [ 43 ] and humans [ 44 ]. This is not surprising considering that glucocorticoids can trigger muscular atrophy, by both inhibiting synthesis and accelerating degradation of muscle proteins in preclinical models, both in vivo and in vitro [ 45 , 46 , 47 , 48 ].…”

Dexamethasone-associated metabolic effects in male mice are partially caused by depletion of endogenous corticosterone

“…In rodents, dexamethasone and corticosterone both cause insulin resistance and muscle atrophy (8)(9)(10). Corticosterone induces adiposity, but the effect of dexamethasone on body composition is not as clear, as both loss and gain of total fat mass have been reported (11)(12)(13).…”