Effects of dietary restriction or swimming on lymphocytes and macrophages functionality from old rats.

Although aging compromises the functionality of macrophages (MΦ) and lymphocytes (LY), and dietary restriction (DR) and exercise partially counterbalance immunosenescence, it is unknown what effects of both strategies have on the functionality of these immune cells. Rats were randomly distributed into adult control (AD), older group (OLD), older submitted to 50% of DR (DR) and older submitted to swimming (EX) (n = 10 in each group). The function of immune cells (proliferative index, phagocytic capacity and H₂O₂ production), the weight and protein content of lymphoid organs (thymus and spleen), plasma glutamine concentration, interleukins (IL-1, IL-2, IL-6) and, immunoglobulins (IgA and IgG) were analysed.

Moderate exercise increases the metabolism and immune function of lymphocytes in rats.

Exercise modulates both glucose and glutamine metabolism which influences lymphocyte function. We investigated the influence of chronic moderate exercise on glucose and glutamine metabolism in lymphocytes, the associated influence on proliferation, and cytokine and immunoglobulin production. Male Wistar rats (8 weeks old) were placed in an exercise training group (N = 15, 1 h day(-1) at 60 % VO₂max, 5 days week(-1)) for 8 weeks of exercise, or a sedentary control group.

Effect of exercise on glutamine metabolism in macrophages of trained rats.

This study investigated the effect of exercise on glutamine metabolism in macrophages of trained rats. Rats were divided into three groups: sedentary (SED); moderately trained (MOD) rats that were swim trained 1 h/day, 5 days/week for 6 weeks; and exhaustively trained (EXT) rats that were similarly trained as MOD for 5 weeks and, in the 6th week, trained in three 1-h sessions/day with 150 min of rest between sessions. The animals swam with a load equivalent to 5.

Reduced maximal oxygen consumption and overproduction of proinflammatory cytokines in athletes.

Objective: It was the aim of this study to evaluate whether chronic pain in athletes is related to performance, measured by the maximum oxygen consumption and production of hormones and cytokines.

Methods: Fifty-five athletes with a mean age of 31.9 +/- 4.

Effects of acute exhaustive physical exercise upon glutamine metabolism of lymphocytes from trained rats.

Transitory immunosupression is reported after intense exercise, especially after an increase in training overload and in overtraining. The influence of intense exercise on plasma hormones and glutamine concentration may contribute to this effect. However, the effect of such exercise-induced changes upon lymphocyte and glutamine metabolism is not known.

Beta-hydoxy-beta-methylbutyrate supplementation affects Walker 256 tumor-bearing rats in a time-dependent manner.

Background & Aims: Cancer cachexia affects intermediary metabolism with intense and general catabolism. Walker 256 tumor is a model injected either subcutaneously (Sc) or intraperitoneally (Ip), with different metabolic features. Beta-hydroxy beta-methylbutyrate (HMbeta) is a leucine metabolite with anti-catabolic properties, the aim of this study being to investigate its effects on metabolic parameters in both tumor models.

Exercise restores immune cell function in energy-restricted rats.

Objective: To evaluate the effect of chronic moderate-intensity exercise upon the alterations of immune system cell function induced by energy restriction.

Methods: Forty male Wistar rats were randomly assigned to the following groups: sedentary animals fed ad libitum (SF, N = 10) or submitted to energy restriction (SER, N = 10, receiving 50% of the mean amount of chow consumed by SF); and trained animals fed ad libitum (TF, N = 10) or submitted to energy restriction (TER, N = 10), who exercised on a treadmill (at 60-65%VO(2max) 5 d.wk(-1) for 10 wk(-1), after 30 d under the restriction protocol.

The profile of melatonin production in tumour-bearing rats.

The pineal gland is involved in the regulation of tumour growth through the anticancer activity of melatonin, which presents immunomodulatory, anti-proliferative and anti-oxidant effects. In this study we measured melatonin content directly in the pineal gland, in an attempt to clarify the modulation of pineal melatonin secretory activity during tumour growth. Different groups of Walker 256 carcinosarcoma bearing rats were sacrificed at 12 different time points during 24h (12h:12h light/dark cycle) on different days during the tumour development (on the first, seventh and fourteenth day after tumour inoculation).

Carnitine supplementation fails to maximize fat mass loss induced by endurance training in rats.

Background/aims: Carnitine is a co-factor of the enzymatic system involved in long chain fatty acid transport across the mitochondrial membrane. This physiological role of carnitine raised the hypothesis that this compound could act as a 'fat burner' by optimizing fat oxidation and consequently reducing its availability for storage. Our aim was to verify whether carnitine supplementation could maximize fat mass loss in trained rats.