Presence of links between zinc and melatonin during the circadian cycle in old mice: effects on thymic endocrine activity and on the survival

Chemical Shift Imaging at 4.7 Tesla of Thymus in Young and Old Mice

“…The T2 relaxation time of thymus is 25% longer than that of muscle (T2 thymus ϭ 48.7 Ϯ 6.2 msec, T2 muscle ϭ 37 Ϯ 6.6 msec). The T1 and T2 relaxation times of skeletal muscle are in good agreement with previously reported data (17). By using the values obtained for the relaxation times of muscle and thymus, and the signal intensity (SI) expression for SE sequences (18), we have calculated the dependence on TR and TE of the relative SI difference between thymus and muscle (SI thymus -SI muscle )/SI thymus .…”

“…The maximum life-span of our inbred Balb/c mice is 30 months. Since most deaths occur at 22-25 months of age, 26-monthold mice can be considered old and 19-month-old mice presenescent (17). Our results demonstrate that in this group of animal the sectional area of the thymus is reduced with respect to the young mice, as is evident in Fig.…”

“…This method could be useful in studies in which experimental manipulation or drug treatments produce changes in the dimension and fat content of this organ (17). Considering that most thymus experiments are performed on rodents, the introduction of CSI techniques could increase the performance of MRI in immunological and pharmacological research.…”

Effect of Melatonin and Zinc on the Immune Response in Experimental <i>Toxoplasma</i> Retinochoroiditis

“…Other potential approaches that deserve further investigation in this respect are the effect of melatonin (MEL) deficiency and artificial MEL supplementation on the immune response to T. gondii infection. MEL is a hormone secreted by pineal gland that has both direct and indirect effects on the immune system [11,12,13,14]. When the pineal gland is removed, significant decreases in the plasma level of zinc, the activity of zinc-dependent hormone, thymulin, plasma level of IL-2, T cell number in peripheral blood, and cytotoxic activity of NK cells are observed, but all of these anomalies are reversed by supplementation with the pharmacological dose of MEL [15,16,17].…”

Zn and Cu alteration in connection with astrocyte metallothionein I/II overexpression in the mouse brain upon physical stress

“…ACTH activity was evident in the rise and fall of corticosterone levels during stress (Simpkiss and Devine, 2003), and blood serum metal ions concentration was consequently modified during stress. In particular, a lack of zinc turnover occurs in stress conditions with an emphasis during the circadian rhythm (nocturnal period) (Mocchegiani et al, 1998). Previous experimental approaches to examining the MT brain response followed the cryolesion model, in which a localized cryolesion is induced in the brain cortex (Hidalgo et al, 2002).…”