Importance of melanin‐based colouration and environment in shaping intracellular glutathione levels in nestling and adult tawny owls Strix aluco

Abstract

Resources allocated in reproduction are traded off against those invested in self-maintenance such as antioxidant response. Glutathione (GSH) is an intracellular antioxidant defence that scavenges reactive oxygen species, the deleterious byproducts of oxygen consumption. Given the role of intracellular GSH in pheomelanogenesis, a trade-off in GSH allocation between resistance in oxidative stress and melanin production may take place. To investigate how intracellular GSH is regulated in differently coloured individuals at the time of reproduction (in adults) and of intense melanogenesis (in nestlings), we measured the total pool of GSH produced ( t GSH), consumed ( ox GSH) and available ( red GSH) in adult tawny owls and their offspring which were cross-fostered between randomly chosen nests. Our goal was to describe potential correlations between resistance in oxidative stress and colour morphs in natural conditions. Nestling GSH levels were correlated with GSH levels in their genetic and foster parents suggesting that producing GSH is genetically and environmentally determined (although the effect of the foster nest seemed stronger). This species shows continuous variation in pheomelanin reddish colouration, which is associated with life-history strategies. Based on the hypothesis of GSH dependence of pheomelanism, we expected a greater amount of ox GSH in dark compared to light pheomelanic nestlings, which was not the case. In contrast, light melanic breeding adults had higher levels of t GSH and red GSH than dark breeders probably because of a higher investment in antioxidant capacity. The link between pheomelanism and GSH may therefore be due to the fact that differently colored individuals have different life-history strategies rather than because the production of pheomelanin pigments requires GSH.

A core–shell liquid metal-Cu nanoparticle with glutathione consumptionviaanin situreplacement strategy for tumor combination treatment of chemodynamic, microwave dynamic and microwave thermal therapy

“…GSH in tumor cells, which is an antioxidant substance, can reduce the reactive oxygen species (ROS) and cytotoxicity, thereby reducing the effect of ROS-based treatment. 23,40,41 Cu 2+ can effectively convert GSH to GSSH, while itself being reduced to Cu + , thereby reducing the GSH content, and enhancing the ROS-based treatment effect. [24][25][26][27][28][29][30][31][32][33] Similarly, this "Cu storage pool" also may be capable of releasing Cu 2+ (Fig.…”