Left Ventricle Myocardium Volume Densities in Spontaneously Hypertensive Rats (SHR) Following Combination of Exercise and ACE Inhibitor Treatment: A Stereological Study

This study was designed to test the possible effects of a combination of physical and pharmacological therapy intervention on myocardial structure of the left ventricle in spontaneously hypertensive rats (SHR). Twelve weeks old spontaneously hypertensive rats (n = 40) were divided into four groups of sedentary, (Sed) as controls, exercise only (Exer), lisinopril only 20mg/kg/day (Lis), and exercise + lisinopril (LisExer). Exercise training was performed on a treadmill (5m/min.) for 60 minutes/day, 5 days/week for 10 weeks. At the end of 10 weeks, all the rats were terminally anaesthetised, the heart was arrested in diastole by intravenous procaine and whole animal perfusion fixation through the abdominal aorta was carried out using Karnovsky's fixative (pH 7.24). The heart was removed and left ventricle plus the interventricular septum was serially sectioned at a thickness of 3 mm. One piece was randomly chosen, and embedded in JB4 resin. Six sections were obtained from each block, stained with toluidine blue:acid fucin. Measurement of volume fraction (Vf), of myocardium, capillaries and interstitium were carried out using a stereology software (Histometrix MIL6 Kinetic imaging Ltd.). Mean Vf of capillaries in Sed group was 0.114 ± 0.01 (SEM). This was significantly increased in LisExer group. The Vf of muscle in Sed group was 0.795 ± 0.02 (SEM). This was significantly decreased in Lis but unchanged in Exer group. Capillaries Vf was significantly higher in LisExer as compared to Lis or Exer groups (p<0.05). Muscle Vf was not different betweenLisExer and Lis groups. The outcome of these changes could well be a better enhancement of cardiac performance in hypertension by combined exercise and ACE inhibitor treatment than either of the interventions alone

Bibliographic Details

Main Authors:	Inuwa,I. M., Hassan,M. O., Ziada,A. M.
Format:	Digital revista
Language:	English
Published:	Sociedad Chilena de Anatomía 2005
Online Access:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022005000200010
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