Leda Lodi

Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects

Background  It has been reported that Omega‐3 fatty acids may play a role in nervous system activity and that they improve cognitive development and reference memory‐related learning, increase neuroplasticity of nerve membranes, contribute to synaptogenesis and are involved in synaptic transmission. The aim of this study was to examine the effects of Omega‐3 supplementation on some cognitive and physiological parameters in healthy subjects.

Changes in the exercise-induced hormone response to branched chain amino acid administration

SummaryIt was the aim of the present experiment to detect possible effects of branched-chain amino acids (BCAA) on the endocrine response to 1 h of continuous running. Blood samples were collected from 14 long-distance runners (age 24–42 years) in two different trials performed at 1-week intervals. In both trials (E and P) blood samples were collected at the following times: 9 a.m. (basal values sample), 10.30 a.m. (sample 90), 11.30 a.m. (sample 150), 12.30 p.m. (sample 210); the athletes performed 1 h of running at a constant predetermined speed between samples 90 and 150. Following the basal sample a mixture containing BCAA (E trial), or not containing BCAA (P trial) was ingested. In both trials no hormone basal concentrations, except insulin, were changed before exercise. In P trial, following exercise (sample 150), human growth hormone (HGH), prolactin (PRL), adrenocorticotropic hormone (ACTH) and cortisol (C) increased, while testosterone (T) decreased. In sample 210, after 1 h of rest, while ACTH, PRL and HGH had recovered to basal concentrations, C remained elevated and T displayed a further decrease. In the E trial a similar pattern of change was observed in sample 150 for HGH, PRL, ACTH and C; in sample 210 HGH and PRL displayed significantly lower values than in the corresponding P trial samples. The T was not modified by the running exercise and increased during the recovery period. It is, therefore, suggested that BCAA administration before exercise affects the response of some anabolic hormones, mainly HGH and T.

Gender-related effects of chronic non-malignant pain and opioid therapy on plasma levels of macrophage migration inhibitory factor (MIF)

Macrophage migration inhibitory factor (MIF) is a cytokine produced by neuroendocrine and immune tissues that possesses several characteristics of a neuroendocrine mediator. Chronic pain is known to affect and to be affected by neuroendocrine and immune mechanisms. In the present study, the plasma levels of MIF and several hormones (cortisol, estradiol, testosterone) were determined to evaluate their mutual behaviour in controls and in chronic pain patients. Blood samples were collected from males and females divided into groups depending on their age (younger or older than 55) and health condition: (1) pain‐free control subjects; (2) chronic non‐malignant pain subjects. Moreover, two additional groups were added to evaluate the effects of short‐ and long‐term opioid administration: (3) short‐term opioid‐treated chronic pain patients and (4) long‐term opioid‐treated chronic pain patients (longer than 6 months). MIF in control/younger men was higher than in all the other control and chronic pain groups. MIF was lower in pain patients than in controls of both sexes. MIF was not changed by morphine administration; its levels remained lower in opioid‐treated subjects than in controls after both short‐ and long‐lasting administration. Chronic pain changed hormone plasma levels differently in male and female patients. MIF was positively correlated with testosterone and negatively with estradiol. These results demonstrate sex differences in the younger men and women and a strong pain‐induced decrease of MIF availability. These findings suggest the involvement of this cytokine in the sex differences observed in chronic pain conditions.

Glucocorticoid receptors in human peripheral blood mononuclear cells in relation to age and to sport activity.

Glucocorticoid receptors (GR) are ubiquitous molecules and are present also in the hippocampus and in several other nervous and immune tissues. Peripheral blood mononuclear cells (PBMCs) are a good model for studies of GR in humans. Glucocorticoids are important for maintaining cellular and humoral homeostasis and are key mediators of neuroendocrine-immune regulatory interactions. The increase of cortisol is immunosuppressive and reduces GR concentration both in nervous and immune systems. Variation of glucocorticoids in healthy aged subjects and athletes has been shown. Prompted by these results, we have investigated in man a possible relationship between GR binding capacity in the PBMCs and age, in relation also to plasma testosterone and cortisol. The same parameters have been examined in a group of soccer players for comparison with the sedentary group. GR binding capacity was higher in younger subjects than in older ones, and lower in the group of athletes than in the younger and older sedentary subjects. In the sedentary group a negative correlation was present between GR binding capacity and age. Plasma cortisol was higher and testosterone lower in the athletes; they were negatively correlated in athletes and positively correlated in the sedentary subjects. The results for athletes agree with their lower anabolic/catabolic balance. The mechanism of reduced GR levels in relation to age and sport activity could involve a loss or an involution of receptor synthesis. However other possibilities, such as altered distribution of lymphocyte subpopulations with different receptor concentrations and with different cytokine production, cannot be excluded. Several neuroendocrine-immune interactions could be responsible for reduced GR levels with age and sport activity in man.

Attention in Athletes of High and Low Experience Engaged in Different Open Skill Sports

In this study were examined differences in attentional style of athletes engaged in two open skill sports requiring high reactivity (karate and volleyball) in groups with high or low experience. 42 healthy men, 24 volleyball players, 12 of High Experience (first division Italian League players whose M age was 28 yr. (SD = 5) and 12 of Low Experience (prejunior Italian team athletes whose M age was 19 yr. (SD = 2), and 18 karateka, 9 of High Experience (3rd and 4th dan black belt athletes whose M age was 31 yr., SD = 5) and 9 of Low Experience (1st and 2nd dan black belt karateka whose M age was 32 yr., SD = 5). Tests involved different types of attention: Alert, Go/No-Go, Divided Attention, and Working Memory. For each one, the reaction time (RT), variability, change in RT, and number of errors were analysed. Karateka of High Experience reacted faster than those of Low Experience on the simple RT test, Alert (M RT: 204 vs 237 msec., p < .01), while on the Divided Attention test, the High Experience subjects performed more poorly and committed more errors (M errors: 4.89 vs 1.44, p < .003). Young volleyball players of Low Experience reacted faster than colleagues of High Experience on the Alert (M RT: 187 vs 210 msec., p < .01) and Divided Attention tests (M RT: 590 vs 688 msec., p < .001) but committed more errors (Divided Attention test, M errors: 6.50 vs 3.08, p < .007). For the Divided Attention and Working Memory tests, correlations were positive among errors, RT, and RT variability but only for volleyball athletes of High Experience, suggesting they showed higher attention and stability in complex reactions than the group with Low Experience. No significant correlations were noted for either group of karateka on complex reactions. Results suggested that the attentional resources were engaged in different ways in the two groups of athletes and, in each group, there were differences between persons of High and Low Experience.

Influence of training on the response of androgen plasma concentrations to exercise in swimmers

In eight top-level male endurance swimmers the aerobic performance and the response to exercise of total testosterone (T), free testosterone (fT), sex hormone binding globulin (SHBG), non-SHBG-bound testosterone (NST) and cortisol (C) were evaluated during a training season. The swimmers participated in three test sessions which occurred 6, 12 and 24 weeks after the beginning of the season. During each session, after a standard warm-up, the swimmers performed a set of 15 × 200-m freestyle, with a 20-s rest between repetitions, at a predetermined individual speed. Three blood samples were collected: before warm-up, at the end of the set, and after 1 h of recovery. A few days before each session, the individual swimming velocity associated with a 4 mmol · l−1 blood lactate concentration (ν4) was assessed as a standard of aerobic performance. The values of ν4 were lower in the second session than in the third one. The concentrations of C, which increased after the exercise, showed the highest values in the second session. The values of T and the T: SHBG ratio increased after the exercise but returned to their initial concentrations during the recovery period. The values of fT and NST increased after the exercise in the first and third sessions. In the initial two sessions, when the aerobic performance was still low, the concentrations of NST decreased to below the initial values after recovery. In session III, when the adaptation to the training workload was complete, NST returned to resting concentrations after recovery. The results would suggest that stressful stimuli produced by an increase in training volume may induce changes in androgen metabolism during exercise. In this respect, NST would appear to be a better index of metabolic response than T, T/SHBG and fT.

Immune and neuroendocrine response to restraint in male and female rats

A parallel study of the modification in the opioid and immunological systems induced by acute restraint (RT) was carried out in male and female rats 24 hr after the treatment. beta-Endorphin-like immunoreactivity (beta-ELI) was measured in two brain areas (ventral hypothalamus [HYP] and periaqueductal gray matter [PAG]) and in the pituitary (anterior and neurointermediate lobes), together with plasma corticosterone (C) and ACTH. Immune function was measured as mitogen-induced Interferon-gamma (IFN-gamma) production by splenocytes. RT reduced beta-ELI levels in the PAG in males and females. Plasma levels of C and ACTH did not differ from the basal levels in restrained animals. RT reduced IFN-gamma production in both sexes, but this effect was more marked in females than in males. The possible relationship between the immune and opioid system is discussed.

Decrease of hippocampal choline acetyltransferase activity induced by formalin pain

The involvement of the hippocampal choline acetyltransferase (ChAT) activity in the response to tonic pain was investigated in rats injected with formalin, either 50 microliters 10% or 50 microliters 0.1%. Hippocampal ChAT activity was found to be reduced both 30 and 60 min after injection of the higher concentration of formalin but only 30 min after the lower one. Results indicate that the decrease in ChAT activity depends upon the presence of the nociceptive input rather than its magnitude. The hippocampal formation is involved in the specific behavioural response to pain, namely licking.

Agonistic behavior, plasma testosterone, and hypothalamic estradiol binding in male rabbits

The purpose of this study was to establish a relation between agonistic behavior, gonadal hormones, and their receptorial capacity at the central level. Male rabbits were observed in seminatural conditions and three components of their agonistic behavior were recorded: follow, attack, and chase. The three behaviors were mutually correlated and clearly differed among the four members of each group. Within the social group, one rabbit was agonistically more active than the others and his supremacy was associated with an increased level of peripheral testosterone and higher estradiol binding in the hypothalamus. On the whole, the values of the hypothalamic estradiol binding were positively correlated with the behaviors. The results show that, in the male rabbit, agonistic activity is associated with changes in testosterone concentration and in the binding at the central level of its aromatized metabolite estradiol. Aggr. Behav. 23:33–40, 1997.

Effect of Omega-3 and Policosanol Supplementation on Attention and Reactivity in Athletes

Objective: The purpose of this study was to determine the effect of omega-3 fatty acids and policosanol supplementation on the cognitive processes involved in the control of reactivity in karateka engaged in attention tests. Methods: Eighteen karateka were randomly assigned to 2 groups. One group (10 subjects) took the supplement of omega-3 fatty acids (2.25 g) plus policosanol (10 mg) (O3 + P) for 21 days, and the other group was supplemented with placebo (oleic sunflower oil). Subjects were tested at the beginning of the experiment (Test 1), after 21 days (Test 2), and after 42 days (Test 3). The experimental procedure consisted of an Alert and a Sustained Attention (SA) reaction time test: the subject had to react by pressing a key of a computer keyboard in Alert and a sequence of 3 keys in SA in response to stimuli, activating a complex go/no-go paradigm. For each test, we recorded the reaction time and the event-related potentials by electroencephalogram and electromyography (EMG) of the forefinger flexor muscle. The Profile of Mood States (POMS) test was also administered. Results: After 21 days of supplementation, subjects who received O3 + P showed a reduced reaction time and increased vigor sensation associated with a reduction of the negative states measured with the POMS test. Analysis of the event-related brain potentials showed a reduced latency of the movement-related brain macropotentials. In particular, the potentials recorded in the premotor period and motor period occurred earlier and the latency of EMG activation was reduced. In the third test, 21 days after the last O3 + P supplementation, the positive effects on the mood state persisted, while the reaction time, EMG, and brain potential latencies increased, although their values remained lower than in the first test. The placebo group did not show any significant differences in Tests 2 and 3 compared to Test 1 for either POMS or reactivity and brain potentials. Conclusions: Supplementation with O3 + P may be effective in improving mood state and reactivity. The reaction time reduction appears to be due to a central nervous system effect, as shown by the reduced latency of movement-related brain macropotentials and EMG activation. These results are in line with previous experiments.