In Vitro Studies on the Metabolism of Human Connective Tissue Cells: Stimulation Factors in the Pathogenesis of Perpetuating Proliferation

The malfunction of tissue repair plays a major role when the pathogenetic sequence in the course of rheumatoid arthritis (RA) is considered. This sequence is initiated by etiologic agents whose nature is still under discussion and comprises vascular reactions, proliferation, and perpetuation of the involved pathologic processes corresponding to the onset and manifestation of the clinical symptoms and the chronic phase of the disease as delineated in Fig. 1. [1] This general outline represents a large variety of individual processes, among others those leading to stimulation of proliferative reactions in the afflicted tissues. Uncontrolled proliferation is known to occur in malignant and benign tissue growth as well as in some inflammatory states. As far as the connective tissues in RA are concerned the number of cells as well as the synthesis and the catabolism of the specific extracellular components are augmented. The control of tissue growth seems to be very complex. Ristow et al. [2] listed 20 different compounds obtained from various sources which are reported in the literature to be activators and regulators of cell growth in fibroblast cultures.