ISSUE 1
In vivo examination of the action of compounds demonstrating in vitro antioxidant activity
There are numerous experimental in vitro assays in the field of Redox Biology, which serve as an introducing stage until the action of various antioxidants is thoroughly apprehended. The extrapolation of data derived from in vitro assays to a living organism is the primary objective. Nevertheless, the in vitro antioxidant action of a compound is not always reflected in an in vivo model.
In vivo examination of the action of compounds demonstrating in vitro antioxidant activity
There are numerous experimental in vitro assays in the field of Redox Biology, which serve as an introducing stage until the action of various antioxidants is thoroughly apprehended. The extrapolation of data derived from in vitro assays to a living organism is the primary objective. Nevertheless, the in vitro antioxidant action of a compound is not always reflected in an in vivo model.
A grape extract is potent antioxidant in vitro
but induces oxidative stress in vivo
An argument between in vitro-like Vmax and in vivo-like Km of muscle catalase
ISSUE 2
The active role of blood in reactive species generation and regulation of tissue redox homeostasis
The scientific paradigm that has dominated in the literature during the previous decades introduces blood as an inactive tissue, which only serves as a receiver of reactive species and other molecules produced in skeletal muscle and other tissues. This opinion seems to be changing, as shown by the increasing number of researchers who are not supporters of this muscle-centric concept. Blood is undoubtfully a carrier of numerous molecules, which are produced in tissues. Yet, blood not only produces potential oxidizing agents and biomarkers of oxidative stress, but also structurally and functionally modifies molecules, originating from other tissues as an outcome of their oxidative modification. Therefore, an important question that emerges is whether the redox biomarkers measured in blood can reflect tissue redox status. This extrapolation is usually made intuitively, however it appears that it cannot apply for all tissues.
The active role of blood in reactive species generation and regulation of tissue redox homeostasis
The scientific paradigm that has dominated in the literature during the previous decades introduces blood as an inactive tissue, which only serves as a receiver of reactive species and other molecules produced in skeletal muscle and other tissues. This opinion seems to be changing, as shown by the increasing number of researchers who are not supporters of this muscle-centric concept. Blood is undoubtfully a carrier of numerous molecules, which are produced in tissues. Yet, blood not only produces potential oxidizing agents and biomarkers of oxidative stress, but also structurally and functionally modifies molecules, originating from other tissues as an outcome of their oxidative modification. Therefore, an important question that emerges is whether the redox biomarkers measured in blood can reflect tissue redox status. This extrapolation is usually made intuitively, however it appears that it cannot apply for all tissues.
Blood reflects tissue redox status in exercise context on the grounds of specific biomarkers
ISSUE 3
The use of animal models to study human Redox Biology
One of the fundamental research questions in the field of Redox Biology is whether the use of animal models (mainly rodents) can contribute to the study of human redox profile. Animal models, and especially rats, are widely used in studies of the field. This is mainly due to the ease of handling and collecting large amounts of blood and tissues (i.e., skeletal muscle and other organs). The ultimate aim of animal studies is the extrapolation of their findings to humans in order to apprehend human's response to a stimulus, namely exercise or nutrition, which is able to alter blood and tissue redox status.
The use of animal models to study human Redox Biology
One of the fundamental research questions in the field of Redox Biology is whether the use of animal models (mainly rodents) can contribute to the study of human redox profile. Animal models, and especially rats, are widely used in studies of the field. This is mainly due to the ease of handling and collecting large amounts of blood and tissues (i.e., skeletal muscle and other organs). The ultimate aim of animal studies is the extrapolation of their findings to humans in order to apprehend human's response to a stimulus, namely exercise or nutrition, which is able to alter blood and tissue redox status.