The effects of angiotensin-converting enzyme inhibitors as a pharmacological treatment for Dupuytren’s disease

Abstract

Dupuytren’s disease is an acquired condition of the hand associated with fibrosis and contraction of the fascia of the palm, leading to stiffness and inability to properly flex and extend the digits. The disease is caused by both genetic and environmental factors. There is some evidence that Angiotensin II (ANGT II) may be associated with this disorder and that blockers of ANGT II may help in treating this disease. This study was designed to investigate the presence of ANGT II receptors 1 (AT1) and 2 (AT2) in myofibroblasts derived from primary tissue of 11 patients who had the disease. My hypothesis is that myofibroblasts will express angiotensin receptors and that these will primarily be of the AT1 receptor subtype.

Initially, the tissues were excised from patients who were undergoing surgery for Dupuytren’s disease in the Department of Plastic Surgery at Royal Preston Hospital. The tissue from each patient was dissociated into myofibroblasts using collagenase. The myofibroblasts from each patient were cultured in a growth medium over a period of 8-10 days. The results show that it was possible to obtain successful growth curves for the myofibroblast following 8-10 days of cell culture. Some cultures produced better yields than others. The myofibroblasts were then stained and treated with specific polyclonal antibodies for the identification of AT1 and AT2 receptors. The results show that both AT1 and AT2 receptors were presented in myofibroblasts taken from all 11 patients. The results show a wider distribution of AT2 receptors compared with AT1 receptors. Samples of the myofibroblasts were employed to measure the contractile response and intracellular free calcium (Ca2+) concentrations. After numerous attempts using a collagen gel model to measure contraction, it was not possible to obtain any successful results. Similarly, fura loaded myofibroblasts show no signs of Ca2+ using a microspectoflurometer to measure intracellular calcium. In conclusion, the results presented in this thesis have shown that it is possible to isolate tissues from patients with Dupuytren’s disease and culture myofibroblasts successfully. Moreover, these myofibroblasts contain both AT1 and AT2 receptors. Further experiments are required to study the role of blocking AT1 and AT2 receptors excitation-contraction coupling process of the myofibroblasts.