Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The natural history and the factors determining the expansion of aneurysms have not been elucidated. To study the respective roles of elastolysis, collagenolysis, inflammatory cells, and hypertension in the pathogenesis of aneurysms, two previously described in vivo experimental models were used. An isolated segment of the abdominal aorta was infused with 15 units of pancreatic elastase. The maximal diameter of the aorta was measured before and after infusion and the isolated aorta was excised for classic histologic and immunohistologic studies. Twelve hours after the infusion of elastase the mean diameter of the aorta increased by 30%. The aorta had a cylindric form and only collagen fibers remained. Two and a half days after the infusion the aorta was spherical in shape and the diameter increased by 300% (3.09 +/- 0.08 mm) (p < 0.05). The entire aortic wall was invested by inflammatory cells. Six days after infusion the diameter increased by 421% (4.38 +/- 0.03 mm) (p < 0.05), and immunohistochemical staining showed numerous T lymphocytes and macrophages. Between 6 and 12 days, after perfusion inflammation decreased, the final diameter was 4.23 +/- 0.14 mm (not significant). Sixteen rats had thioglycollate and plasmin infusion, which are nonspecific activators of inflammation. Nine days after infusion the diameter of the aorta had increased by 288%; the elastic fibers of the media were fragmented and rare and the entire aortic wall was invaded by inflammatory cells, predominantly macrophages. The diameter of the aorta increased progressively. Two groups of 17 hypertensive rats (renovascular and spontaneous hypertension) received an aortic infusion of 15 units of pancreatic elastase. Elastolysis overlapped the limits of the infusion and inflammation persisted after 2 weeks. The mean diameter of the aorta (F = 11, p < 0.01) and the mean length of the aneurysms (F = 11.2, p < 0.001) were significantly increased. This study demonstrates that elastolysis and especially collagenolysis are determinants of aneurysmal expansion. Inflammation may be a promoting factor in the degradation of the aortic wall. Hypertension increases the hemodynamic stress to the aorta and activates mural inflammation.
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PMID:Experimental study of determinants of aneurysmal expansion of the abdominal aorta. 819 45

Elastolysis, collagenolysis and gelatinolysis are essential in the pathogenesis of tobacco smoke-induced emphysema; however, these activities have been scantily studied in emphysema secondary to woodsmoke. The aim of this study was to analyze elastolysis, collagenolysis and gelatinolysis, MMP-1, MMP-2, and MMP-9 expression, and apoptosis in guinea pigs exposed to smoke produced by 60 g/day of pine wood, 5 days/week, from 1 to 7 months. Histological analysis after 4 to 7 months in smoke exposed guinea pigs showed alveolar mononuclear phagocyte and lymphocytic peribronchiolar inflammation, epithelial and smooth muscle hyperplasia, and pulmonary arterial hypertension. Mild to moderate emphysematous lesions were observed in woodsmoke-exposed animals at 4 to 7 months by increase of mean linear intercepts. A higher percentage of whole blood carboxyhemoglobin (COHb) and elastolytic activity in bronchoalveolar lavage macrophages and lung tissue homogenates was observed at all times. Collagenolysis was increased after 4 to 7 months in woodsmoke-exposed animals, although collagen concentration did not change. Zymography revealed increase in lysis bands of the active MMP-2 and MMP-9 at 4 and 7 months in bronchoalveolar lavage fluid and lung tissue homogenate. Positive immunostaining for MMP-1 and MMP-9 was observed in epithelial cells and macrophages in wood exposed animals at 4 to 7 months. Real-time PCR showed MMP-2 and MMP-9 expression at 3 to 7 months in exposed animals. Furthermore, apoptosis was increased at all times in bronchoalveolar lavage macrophages and lung tissue from exposed animals. Results support a role of metalloproteinases and apoptosis in emphysema secondary to woodsmoke exposure.
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PMID:Increase of matrix metalloproteinases in woodsmoke-induced lung emphysema in guinea pigs. 1883 20