This chapter describes the characteristics of the vascular system in cats and dogs, including blood flow, blood vessels, the role of blood in biochemical transport, blood composition, haematology, blood clotting, haemodynamics, cardiac rhythm and the lymphatic system. Some medical conditions that...

Glutamate decarboxylase (GAD) catalyses the decarboxylation of glutamate to produce γ-aminobutyric acid (GABA). In plants, its activity is modulated by pH and calcium. The regulation of GAD activity by calcium is through a calmodulin binding domain that seems to be specific for the plant kingdom,...

Amino acids are the main form of nitrogen transported in the plant body, and the transport of amino acids across cellular and sub-cellular membranes is considered essential for nitrogen economy in plants. In particular, the long-distance transport of amino acids through the phloem and xylem, and...

This chapter focuses on polyamine synthesis, degradation, conjugation and transport in plants, and on the regulation of polyamine and polyamine-metabolizing enzymes under salinity, drought and cold stress. Advances in transgenic approaches with polyamine-regulatory genes to improve stress tolerance ...

This chapter provides an overview of the physiological roles (i.e. in embryogenesis, vegetative growth and reproduction) and metabolism (biosynthesis, catabolism, regulation and transport) of polyamines in plants, and discusses the role of polyamines in plant abiotic (cold stress, drought, heavy...

Asparagine (Asn) is an amino acid which serves as a carrier and storage form of nitrogen. In this chapter, the history, chemical properties and general role of Asn will be examined, followed by an account of the history of asparagine synthetase (AsnS) research in humans, microbes and plants. The...

Recent data suggest that D-serine is the endogenous ligand for the 'glycine' binding site of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor. This chapter reviews evidence that this is the case, not only in brain, but also in the retina. Information is provided documenting the...

Brain capillary endothelial cells form the blood-brain barrier (BBB). They are connected by extensive tight junctions, and are polarized into luminal (blood-facing) and abluminal (brain-facing) plasma membrane domains. The polar distribution of transport proteins mediates amino acid (AA)...

Plasma amino acid pools are regulated by production and disposal. Whereas essential amino acids are dependent on protein breakdown for their plasma flux, non-essential amino acids are produced de novo within the body. In many instances these production processes are encased in metabolic cycles,...

The early-divergent protozoan Giardia lamblia, which is a major cause of waterborne enteric disease worldwide, was shown to possess limited lipid synthesis ability and to depend upon preformed lipid molecules for energy production and membrane biosynthesis. Therefore, questions regarding how ...