Rice 114 the inflammatory response. Most cytokines are pleiotropic, displaying functional plasticity and redundancy. They are involved in extensive, complex networks and may act synergistically as well as antagonistically in regulating target cell function. Human parturition displays many of the hallmarks of an inflammatory response, thus, the aim of this review is to consider the data available implicating cytokines in the initiation and/or progression of human parturition. To assess the putative involvement of cytokines in the process of human parturition an appreciation of their general biology is a requisite.Cytokines are low molecular weight polypeptides involved in the regulation of cell growth, activation and cell repair, immune responses, inflammation, hemopoiesis and fibrosis. Proteins classified as cytokines include interleukins (ILs), tumor necrosis factors (TNFs), interferons (IFNs), colony-stimulating factors (CSFs), erythropoietin, thrombopoietin and various other growth factors. This review focuses on the ILs and TNFs and their putative role in the proximal events involved in the initiation and/or progression of parturition.
Interleukin-1: 2q14Structure Two functional forms of IL-1 (aka endogenous pyrogen, lymphocyte-activating factor), IL-1· (17 kD, 159 amino acids, pI = 5.0) and IL-1ß (17 kD, 153 amino acids, pI = 7.0) that are encoded by two different genes on chromosome 2 have been identified. The · and ß forms display approximately 27% homology, mainly restricted to the carboxy-terminal region, and their effects are mediated via the same receptor. IL-1s are synthesized as precursor molecules that are proteolytically cleaved to release mature peptides. The IL-1ß precursor can be cleaved by proteases including caspase-1, elastase, cathepsin G, and collagenase.
ExpressionCells known to express IL-1· include: