ABSTRACT
BACKGROUND: Extracellular matrix degradation may play an important role in the etiology of urethral stricture. MMP1 and TIMP1 are involved in extracellular matrix degradation. The aim of this study was to investigate the roles of MMP1, TIMP1, and MMP1:TIMP1 ratio at the remodeling phase of urethral stricture in an animal model. METHODS: This research was carried out in collaboration between the Bogor Institute of Agriculture, Universitas Indonesia, and the Eijkman Institute Indonesia. This was an experimental in vivo study in adult male New Zealand rabbits, divided into two groups: a urethral stricture group and a control group. Euthanasia was performed in four rabbits of each group on days 7, 14, 21, 28, and 56. Urethral stricture was confirmed with an 8 F urethral catheter. Several laboratory examinations were done, including H&E and Masson trichrome staining, immunohistochemistry, and ELISA, to determine levels of MMP1 and TIMP1. Percentages of total collagen and collagen type 1 were counted with ImageJ 1.46q software. A general linear model was used for statistic analysis. RESULTS: We found that the level of MMP1 was lower, TIMP1 higher, and MMP1:TIMP1 ratio lower in the urethral stricture group than the control group. There was a correlation between MMP1 level with total collagen percentage (r=0.561, P=0.010) and no correlation between TIMP1 and total collagen (r=0.307, P=0.188). CONCLUSION: Imbalance in extracellular matrix degradation was marked by decreased MMP1 level and MMP1:TIMP1 ratio and increased TIMP1 level. This results showed that urethral stricture is not only caused by collagen decomposition, but also by the imbalance of extracellular matrix degradation.
ABSTRACT
BACKGROUND: This study was performed to assess the role of ischemic preconditioning on cardiomyocyte apoptosis after open heart surgery, based on morphology by transmission electron microscopy, caspase-3 activity, biochemical markers, and cardiac performance. METHODS: 12 piglets were divided into 2 equal groups: an ischemic preconditioning group and a control group. Ventricular muscles were collected to examine apoptotic ultrastructure morphology and caspase-3 activity. Blood samples from the coronary sinus were obtained for measurement of tumor necrosis factor-α, malondialdehyde, and cardiac troponin I. Aortic blood samples were taken for lactate measurements before and after cardiopulmonary bypass. Cardiac performance was measured by echocardiography before and after surgery. RESULTS: Cardiomyocyte apoptosis occurred postoperatively, as shown by ultrastructure observation. Caspase-3 activity was less in the ischemic preconditioning group than the control group (p < 0.05). Measurements of specific markers of cardiomyocyte injury also showed lower increases in the ischemic preconditioning group, although not significantly different. Clinical outcomes showed that ischemic preconditioning was able to preserve cardiac performance in terms of ejection fraction, cardiac index, and stroke volume index; these were statistically significant, except for lactate concentration. CONCLUSIONS: Cardiomyocyte apoptosis occurs after open heart surgery. Ischemic preconditioning can reduce cardiomyocyte apoptosis and improve cardiac performance. Laboratory findings showed that ischemic preconditioning prevents injury of cardiomyocytes and reduces lactate concentration, although not statistically significant.
