The Role of Protease Activated Receptors in Lung Inflammation - Term Paper Example

Currently, PARS-caused lung inflammation is treated by oral drug therapy, but in the future gene therapy and the use of PAR antagonist shows great hope. Overall, PAR-AP-induced inflammatory responses in the lung are substantially dependent upon neurogenic mechanisms. Thus PARs are key components in inflammatory reactions and in this case lung inflammation through the explained mechanism.

1.0 Introduction

1.1 Definitions of PARS

Receptors are defined as a protein molecules, engraved in the cytoplasm or the plasma membrane of a cell, to which one or more specific kinds of molecules of hinting nature may adhere to. Biochemistry defines a receptor as a protein molecule, engraved in the cytoplasm or cell membrane of a cell, to which a moving molecule of hinting nature may adhere (Macfariane et al., 2001: 247-251). Ligand is a molecule that attaches to a receptor, and it might be a peptide or any other small molecule, like a neurotransmitter, toxin, or drug, and when binding of such kind occurs, these molecules ordinarily initiate a cellular response, though some ligands merely block receptors without triggering any response. Each kind of receptor can attach only to certain ligand shapes. Each cell typically has many receptors of different kinds. When such binding occurs, the receptors undergo a conformational change, which is a change in the three-dimensional shape of the receptor protein, without changing its sequence, which ordinarily initiates some sort of cellular response (521-254). However, some ligand-like antagonists merely block receptors without inducing any response. Ligand-induced changes in receptors result in cellular changes which constitute the biological activity of the ligands. Many functions of the human body are regulated by these receptors responding uniquely to specific molecules like this (Asokanathan et al., 2002: 3577-3580).

1.2 Type of receptors

Some receptor proteins are peripheral membrane proteins. Many hormone and neurotransmitter receptors are transmembrane proteins; transmembrane receptors are embedded in the phospholipid bilayer of cell membranes that allow the activation of signal transduction pathways in response to the activation by the binding molecule or ligand (Nystedt et al., 1994: 9208-9212). Metabotropic receptors are coupled to G proteins and affect the cell indirectly through enzymes that control ion channels. Ionotropic receptors, also called ligand-gated ion channels contain a central pore that opens in response to the binding of ligands. Intracellular proteins such as those for steroid and intracrine peptide hormone receptors and these receptors often can enter the cell nucleus and modulate gene expression in response to the activation by the ligand (Macfariane et al., 2001: 250-273).

1.2.1 Pathology in which PARS is implicated

PARs are implicated in cancer, arthritis, renal failure, edema, diabetes, etc this is one of the initial responses of the immune system toward infection or irritation. Inflammation is distinctly identified by two unique symptoms of redness and swelling which are due to blood flow into the tissue of the target (Kawai & Akira, 2006: 133-135). Eicosanoids and cytokines are the major cause of inflammation when they are released by trauma or infected tissues or cells (Middleton et al, 2000: 676-677). Prostaglandins and leukotrienes are categorized as eicosanoids, with the former concerned with producing fever and dilation of blood vessels and the latter concerned with pulling on specific leukocytes (Miller, 2006: 40-45).