TRPA1 channels: novel targets of 1,4-dihydropyridines

Transient receptor potential type A1 (TRPA1) channels are cation permeable channels activated by irritant chemicals and pungent natural compounds. Their location in peptidergic sensory terminals innervating the skin and blood vessels makes them important effectors of vasodilator responses of neural origin. 1,4-dihydropyridines are a class of L-type calcium channel antagonists commonly used in the treatment of hypertension and ischemic heart disease. Here we show that four different 1,4-dihydropyridines (nifedipine, nimodipine, nicardipine and nitrendipine), and the structurally related L-type calcium channel agonist BayK8644, exert powerful excitatory effects on TRPA1 channels. The activation does not depend on elevated Ca2+ levels and cross-desensitizes with that produced by other TRPA1 agonists. The activation produced by nifedipine was reduced by camphor and the selective TRPA1 antagonist HC03001. In a subclass of mouse nociceptors expressing TRPA1 channels, assessed by responses to the TRPA1 agonist mustard oil, nifedipine also produced large elevations in [Ca2+](i). These responses were fully abrogated in TRPA1(-/-) mice. These findings identify TRPA1 channels as a new molecular target for the 1,4-dihydropyridine class of calcium channel modulators.     

Impacto del ejercicio físico en variables relacionadas con el bienestar emocional y funcional en adultos mayores

Background and aimThe benefits of the physical exercise in aging, and specially in frailty, have been associated with reduced risk of mortality, chronic disease, and cognitive and functional impairments. Multi-component training, which combines strength, endurance, balance, and gait training, represents the most beneficial kind of physical exercise in older adults.MethodsGiven the effectiveness of the multi-component training, a physical exercise program «Actívate» (based on the methodology Vivifrail), with the focus on «active aging», was conducted in the present study. Forty-nine older adults over 60 years participated in this program.ResultsThe physical exercise intervention led to a reduction in diastolic blood pressure, pain threshold and sleep disturbances (e. g. hypersomnia) (t ≥ 2.72, p < 0.01), as well as an increase of walking speed (t = 7.84, p ≤ 0.001). Further, quality of life factors (GENCAT scale), like emotional well-being, personal development, physical well-being, self-determination, and social inclusion, were greater after intervention (t ≥ ?2.06, p < 0.05).ConclusionsThese findings underline the benefits of multi-component training in functionality of older adults, and further, provide relevant aspects about the modulation of pain perception, sleep disturbances, social factors and physical and emotional well-being. Physical exercise programs such as «Actívate» should be promoted, in order to encourage healthy lifestyle habits, in the older adults’ population.     

The continuity of living matter and the discontinuities of its constituents: do plankton and benthos really exist?

Plankton and benthos are popular concepts identifying two ways of life of aquatic organisms. Their spatial separation led to the development of different sampling techniques and to separate conceptualizations of the principles governing these subsets of the aquatic environment. Reciprocal connections between plankton and benthos, however, are very strong both from a functional (energy fluxes) and a structural (life cycle dynamics) point of view. A full appreciation of such links is forcing marine ecology towards a more integrated approach.     

Effect of a high-intensity exercise training on the metabolism and function of macrophages and lymphocytes of walker 256 tumor bearing rats

Epidemiologic studies suggest that moderately intense training promotes augmented immune function, whereas strenuous exercise can cause immunosupression. Because the combat of cancer requires high immune function, high-intensity exercise could negatively affect the host organism; however, despite the epidemiologic data, there is a lack of experimental evidence to show that high-intensity training is harmful to the immune system. Therefore, we tested the influence of high-intensity treadmill training (10 weeks, 5 days/week, 30 mins/day, 85% VO(2)max) on immune system function and tumor development in Walker 256 tumor-bearing Wistar rats. The metabolism of glucose and glutamine in lymphocytes and macrophages was assessed, in addition to some functional parameters such as hydrogen peroxide production, phagocytosis, and lymphocyte proliferative responses. The metabolism of Walker 256 cells was also investigated. Results demonstrated that high-intensity training increased the life span of tumor-bearing rats, promoted a reduction in tumor mass, and prevented indicators of cachexia. Several changes, such as a reduction in body weight and food intake and activation of glutamine metabolism in macrophages and lymphocytes induced by the presence of Walker 256 tumor, were prevented by high intensity training. The reduction in tumor growth was associated with an impairment of tumor cell glucose and glutamine metabolism. These data suggest that high-intensity exercise training may be a viable strategy against tumors.