Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Metabolic adaptation of skeletal muscle to high altitude hypoxia: how new technologies could resolve the controversies
Effective new treatments of heart disease are based on a refined understanding of
cellular function and the heart's response to environmental stresses. Not surprisingly
therefore, the field of experimental cardiology has experienced a phase of rapid exponential
growth during the last decade. The acquisition of new knowledge has been so
fast that textbooks of cardiology or textbooks of cardiovascular physiology are often
hard-pressed to keep up with the most important conceptual advances.
Under natural conditions the compartmentalization of the digestive tract of ruminants is a vital adaptation to the utilization of the biomass they select with grazing or browsing. The evolution of the reticulorumen made it possible to retain fibrous material in the rumen for long periods, and to sustain a microbial....
Phototrophy is the process by which organisms trap photons and store energy as chemical
energy in the form of adenosine triphosphate (ATP). ATP transports chemical energy within
cells for metabolism. There are three major types of phototrophy: Oxygenic and Anoxygenic
photosynthesis, and Rhodopsin-based phototrophy. Photosynthesis is a chemical process
that converts carbon dioxide into different organic compounds using solar energy. Oxygenic
and anoxygenic photosynthesis undergo different reactions in the presence and absence of
light (called light and dark reactions, respectively).
THE EXTENT AND TIMING OF PLANT GROWTH are controlled by the coordinated actions of positive and negative regulators. Some of the most obvious examples of regulated nongrowth are seed and bud dormancy, adaptive features that delay growth until environmental conditions are favorable. For many years, plant physiologists suspected that the phenomena of seed and bud dormancy were caused by inhibitory compounds, and they attempted to extract and isolate such compounds from a variety of plant tissues, especially dormant buds.
The classical metabolic control theory [Kacser, H. &
Burns, J.A. (1973)Symp.Soc.Exp.Biol. 27, 65–104;
Heinrich, R. & Rapoport, T. (1974)Eur. J. Biochem.42,
89–95.] does not take into account experimental evidence
for correlations between enzyme concentrations in the
cell. We investigated the implications of two causes of
linear correlations: competition between enzymes, which
is a mere physical adaptation of the cell to the limitation
of resources and space, and regulatory correlations,
which result from the existence of regulatory networks....
Plants inhabiting high alpine and nival zones are considered as living in an extreme
Extreme environments have been attractive for explorers for centuries, and nowadays
they also attract tourists. Fortunately biological science is becoming increasingly
aware that these remote habitats provide challenging questions that will help to
understand the limits of life functions.
Acomputational approach is used to analyse temporal gene
expression in the context of metabolic regulation. It is based
on the assumption that cells developed optimal adaptation
strategies to changing environmental conditions. Time-dependent enzyme profiles are calculatedwhichoptimize the
function of a metabolic pathway under the constraint of
limited total enzymeamount.For linearmodel pathways it is
shown thatwave-like enzyme profiles are optimal for a rapid
Adaptation to Hypoxia An important component of the respiratory response to hypoxia originates in special chemosensitive cells in the carotid and aortic bodies and in the respiratory center in the brainstem. The stimulation of these cells by hypoxia increases ventilation, with a loss of CO2, and can lead to respiratory alkalosis. When combined with the metabolic acidosis resulting from the production of lactic acid, the serum bicarbonate level declines (Chap. 48).
Define ecological biochemistry. • Explain biochemical adaptation and the roles of secondary compounds. • Describe detoxification and the primary metabolic pathways in plants and animals. • Explain the key processes and factors involved in biotransformation & biodegradation. • Explain the concepts of sequestration, bioaccumulation, and biomagnification. • Contrast different forms of ecological biochemical interaction.
Peroxisomes are cell organelles that are present in almost all eukaryotic
cells and involved in a large range of metabolic pathways. The organelles
are highly dynamic in nature: their number and enzyme content is highly
variable and continuously adapts to prevailing environmental conditions.
This review summarizes recent relevant developments in research on pro-cesses that are involved in the regulation of peroxisome abundance and
All cells, from prokaryotes to vertebrates, synthesize enormous amounts of
rRNA to produce 1–2 million ribosomes per cell cycle, which are required
to maintain the protein synthesis capacity of the daughter cells. In recent
years, considerable progress has been made in the elucidation of the basic
principles of transcriptional regulation and the pathways that adapt cellular
rRNA synthesis to metabolic activity, a process that is essential for under
In yeast, a sudden transition from glucose limitation to glucose excess leads
to a new steady state at increased metabolic fluxes with a sustained
decrease in the ATP concentration. Although this behaviour has been
rationalized as an adaptive metabolic strategy, the mechanism behind it
Saccharomyces cerevisiaeis known to be able to adapt to the presence of
the commonly used food preservative benzoic acid with a large energy
expenditure. Some mechanisms for the adaptation process have been sug-gested, but its quantitative energetic and metabolic aspects have rarely been
Pyruvate is located at a crucial crossroad of cellular metabolism between
the aerobic and anaerobic pathways. Modulation of the fate of pyruvate,
in one direction or another, can be important for adaptative response to
hypoxia followed by reoxygenation.
The abundance and size of cellular organelles vary depending on the cell
type and metabolic needs. Peroxisomes constitute a class of cellular organ-elles renowned for their ability to adapt to cellular and environmental
conditions. Together with transcriptional regulators, two groups of per-oxisomal proteins have a pronounced influence on peroxisome size and
In this chapter, we will address the following questions: what is photosynthesis? How does photosynthesis convert light energy into chemical energy? How is chemical energy used to synthesize carbohydrates? How do plants adapt to the Inefficiencies of photosynthesis? How is photosynthesis connected to other metabolic pathways in plants?
This chapter presents the following content: Gross anatomy of a skeletal muscle, microscopic anatomy of a skeletal muscle fiber, sliding filament model of contraction, physiology of skeletal muscle fibers, contraction of a skeletal muscle, muscle metabolism, force of muscle contraction, velocity and duration of contraction, adaptations to exercise.