Skeletal Muscle and Liver Oxidative Metabolism in Response to a Voluntary Isocaloric Intake of a High Fat Diet in Male and Female Rats

Abstract

High fat diets (HFD) usually lead to hyperphagia and body weight gain. However, macronutrient proportions in the diet can modulate energy intake and body fat deposition. The aim of the study was to investigate muscle and liver oxidative metabolism in response to an isocaloric intake of a HFD and to elucidate the possible gender-dependent response. Eight week-old male and female rats were fed either standard chow or HFD for 14 weeks. Energy intake, body weight and whole animal oxygen consumption were determined periodically. Mitochondrial oxygen consumption, hydrogen peroxide production, TBARS levels, Cytochrome-c-oxidase, Citrate synthase and antioxidant enzyme activities were measured in muscle and liver. UCP1 and UCP3 protein levels were analyzed in brown adipose tissue and muscle, respectively. Male rats showed higher energy efficiency, enhanced adiposity, greater hydrogen peroxide production and less effective antioxidant machinery compared to females. HFD feeding increased energy expenditure but did not modify either tissue oxidative metabolism or oxidative damage in either gender. HFD animals over-expressed uncoupling proteins in order to maintain energy balance (brown adipose tissue UCP1) and to avoid oxidative stress (skeletal muscle UCP3), thus counteracting the alterations induced by the modification of the proportion of macronutrients in the diet.

Estradiol stimulates mitochondrial biogenesis and adiponectin expression in skeletal muscle

“…As skeletal muscle from female rats exhibits greater mitochondrial mass, antioxidant protection, and oxidative-phosphorylative capacities than that from males (Colom et al 2007a, Català-Niell et al 2008, Gó mez-Pérez et al 2008, and E 2 has been shown to play a role in mitochondrial modulation in other tissues (Mattson et al 1997, Chen et al 1999, Rodríguez-Cuenca et al 2007, Moreira et al 2011, Nadal-Casellas et al 2011b, Amengual-Cladera et al 2012a, the aim of the present study was to elucidate the role of sex hormones in these differences, as well as their relationship with adiponectin production in skeletal muscle. This was accomplished by using a model of ovariectomized (OVX) rats to test the effects of a decrease in ovarian hormone levels and of E 2 replacement, combined with in vitro experiments with L6E9 myotubes, which were treated with E 2 , progesterone (Pg), and testosterone.…”

Gender-dependent differences of mitochondrial function and oxidative stress in rat skeletal muscle at rest and after exercise training

“…In accordance with our findings, other authors have reported higher oxidative capacity in the gastrocnemius muscle of female Wistar rats. Català-Niell et al [12] demonstrated higher mitochondrial respiration at state 4 and state 3. Colom et al [10] found higher enzymatic activities for some electron transport chain complexes in the mitochondria of females compared with males.…”

“…Redox status also shows gender differences, as female rats often suffer less oxidative damage than males. Català-Niell et al [12] reported that muscle mitochondria from females produce significantly less hydrogen peroxide and have more effective antioxidant capacities than those from males.…”

“…Gender differences have been observed in response to oxidative stress, as female rats often show lower oxidative damage than males [12]. Exercise-induced oxidative stress may also show some differences between the sexes in humans and animals [13].…”

Uncoupling protein 1 expression and high-fat diets

“…Twenty-three employed the mouse as an animal model (1, 3-5, 11, 15-17, 25, 32, 33, 40, 44, 49, 52, 53, 57, 63, 67, 74, 75, 78, 79), 16 employed the rat (6,23,35,38,42,43,48,58,70,71,73,77,80,82,84,85) and one used the Brandt's vole (86) and the house shrew (69), respectively. Whenever possible, we compared both the regulatory effect of a given parameter across different studies and within the same study.…”