Are mast cells involved in hypertensive heart disease?
OBJECTIVE: To evaluate the potential relationship of mast cells with myocardial fibrosis in the cardiac ventricles of spontaneously hypertensive rats (SHR). DESIGN: Experiments were performed on hearts from 36-week-old SHR with established left ventricular hypertrophy (n = 12) and from 36-week-old normotensive Wistar-Kyoto (WKY) rats (n = 12). Furthermore, to evaluate whether antihypertensive treatment with the angiotensin converting enzyme inhibitor quinapril interferes with the potential relationship between mast cells and fibrosis in SHR, we treated 16-week-old SHR (n = 12) with oral quinapril (10 mg/kg body weight per day) for 20 weeks. METHODS: Mast cells were counted in 25 high-power fields. Toluidine blue-stained sections and avidin staining were used to detect mast cells. The extent of myocardial fibrosis was analysed in samples stained with Masson’s trichrome. The amount of collagen was evaluated morphometrically, using an automatic image analyser, and biochemically, using myo