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M Laplace

Publications and source records attributed to M Laplace.

21 records · Page 2Linked to original sources

Development and reversal of pressure-induced cardiac hypertrophy. Light and electron microscopic study in the rat under temporary aortic constriction.

Light and electron microscopy, combined with morphometry, were utilized to study myocardial cell modifications induced by a temporary abdominal aortic constriction in the rat. During the early stage of active hypertrophy, cell enlargement in the subendocardial layers of the left ventricle was predominant. This enlargement may be partly due to intracellular edema, characteristic of cell damage. Degenerative foci leading to fibrous scars were found primarily in the subendocardium and midwall layers. The times taken by the different cell structures to adapt to modifications of the load were rather different; some adapted very rapidly (nucleoli, intercalated discs), while others were much slower (cell diameter, mitochondria).

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Aorto-caval fistula in the rat. An experimental model of heart volume overloading.

Abdominal aorto-caval fistula was experimentally induced in rats, and animals were sacrificed 5 days, 1 month, and 6 months later. Cardiac weight almost doubled the normal weight during the first month. Cell length increased to the same extent as the cell width, indicating harmonious growth. Increase in cell volume, as well as the amount of degenerative changes, were more pronounced in subendocardium than in midwall and subepicardium. Cytological features of active cellular growth was found not only in the early stages (5 days and 1 month) but also 6 months after the operation. This finding is consonant with proteosynthesis stimulation not only in the early period of constitution of hypertrophy but also in the later stages.

Animals↗