PMID: 9166291May 1, 1997Paper

Differential regulation of matrix metalloproteinases associated with aging and hypertension in the rat heart

Laboratory Investigation; a Journal of Technical Methods and Pathology
V RobertC Delcayre

Abstract

We compared two models of cardiac fibrosis in which collagen synthesis is controlled at different levels. Regulation is pretranslational in aldosterone-salt-induced hypertension in young rats and posttranslational in 24-month-old rats. However, little is known about the role of matrix metalloproteinases (MMP) in fibrosis development. Ventricular MMP activities were studied by zymography, and MMP-2 and MMP-1 mRNA levels were determined using slot-blot and ribonuclease protection assay, respectively. After 1 month of aldosterone-salt treatment, proMMP-2, MMP-2, and proMMP-1 collagenolytic activities and their gene expression were unchanged compared with sham-operated rats. After 2 months, total MMP-2 activity was increased by 40% with parallel stimulation of its gene expression. These changes were localized by in situ zymography within the media of coronary vessels. These results suggest that MMP play a prominent role in vascular remodeling during the first steps of hypertension. During aging, however, there were 40% and 45% decreases in MMP-2 and proMMP-1 activity, respectively, with a corresponding down-regulation of MMP-2 mRNA. These observations suggest that depression of the degradative pathway is partly responsible for age-...Continue Reading

Related Concepts

Related Feeds

Cardiovascular Diseases: Risk Factors

Cardiovascular disease is a significant health concern. Risk factors include hypertension, obesity, dyslipidemia and smoking. Women who are postmenopausal are at an increased risk of heart disease. Here is the latest research for risk factors of cardiovascular disease.