Effects on the myocardium, particularly those structural properties of the capillary network relevant to tissue oxygenation, were studied morphometrically in rats subjected to a severe running program. Physical conditioning produced a 31% increase in right ventricular weight and only a 12% increase in the weight of the left ventricle. Quantitative analysis of right ventricular myocardium demonstrated relative decreases in capillary luminal volume density (-27%) and capillary luminal surface density (-20%) and an increase in the average maximum distance from the capillary wall to the mitochondria of myocytes (14%). In contrast, the contractile mass expanded in proportion to the growth of the ventricle through augmentation of the cross-sectional area (17%) and length (19%) of the average myocyte. Evaluation of the subcellular constituents of myocytes showed no change in the mitochondria-to-myofibril volume ratio. In conclusion, the capillary bed controlling oxygen availability, diffusion, and transport suggests that excessive physical activity may be detrimental to the myocardium.
|Data di pubblicazione:||1982|
|Titolo:||Morphometry of right ventricular hypertrophy induced by strenuous exercise in rat.|
|Rivista:||AMERICAN JOURNAL OF PHYSIOLOGY|
|Codice identificativo Scopus:||2-s2.0-0020346222|
|Parole Chiave:||animal; article; body weight; capillary; cardiomegaly; coronary artery blood flow; coronary blood vessel; exercise; heart; heart atrium; histology; organ weight; pathophysiology; rat; rat strain.|
|Appare nelle tipologie:||Articolo su Rivista|