Cultivo de cardiomiócitos suínos / Culture of swine cardiomyocites

A insuficiência cardíaca é uma das doenças mais deletérias no mundo ocidental. Muitas pesquisas foram desenvolvidas com o intuito de promover novos e mais eficientes abordagens terapêuticas para a doença. Estas novas propostas terapêuticas tem ênfase nas origens dos processos patológicos e no reestabelecimento da funcionalidade, tal como nos transplantes de células lisas ou estriadas musculares, de cardiomiócitos fetais e adultos no tecido cardíaco fibrosado. Neste estudo, protocolos desenvolvidos e testados em ratos e camundongos e previamente publicados foram adaptados para cardiomiócitos suínos, objetivando estabelecer um protocolo para cultivo de cardiomiocitos em suínos. Três protocolos foram testados (A- digestão enzimática em coração de adulto, B- digestão enzimática em coração fetal e C- explante de coração adulto e fetal) e apenas um produziu resultados confiáveis (protocolo B) sugerindo a formação de fibras cardíacas, no entanto, faz-se necessária avaliação imunocitoquímica e análises ultraestruturais para a confirmação da hipótese.

Cardiac insufficiency is one of the most harmful disease in the occidental world; A range of researches have been developed in order to provide new and more efficient therapeutics for the disease. New therapeutics purposes have been directed to the origin of the pathological process and aim to re-establish functional physiology, as in transplants of cells like smooth or striated muscular cells, fetal or adult cardiomyocytes into the fibroid myocardium. In this study, previous published protocols developed in rats and mice were adapted for swine cardiomyocytes. The main goal was to stablish a viable protocol for swine cardiomiocyte culture, and the establishment of an experimental model using swine. Three protocols were tested (A - enzimatic digestion in adult heart; B- enzimatic digestion in fetal heart; C - explant of samples of adult and fetal hearts. We observed that protocol B produced a reliable result suggesting cardiac fibre formation, although, further immunecitochemistry and ultrastructural will be investigated to confirm the hypothesis.

[Fetal human myocardium. Proliferation of the myocytes and development of the cardiac interstitium in the last two gestational trimesters]. / Miocárdio fetal humano. Proliferação do miócito e desenvolvimento do interstício cardíaco nos dois últimos trimestres gestacionais.

PURPOSE: To determine prenatal myocardial quantitative changes by using stereology. METHODS: Twenty-six human fetuses were studied (16 in the 2nd trimester and 10 in the 3rd trimester). The hearts were dissected, weighted, fixed in the Bouin's solution for 12 h, embedded in paraplast, sectioned and stained by HE and trichrome of Gomori. Ten random microscopic fields were analyzed by heart. The following parameters were studied: Vv[myocyte] and Vv[interstitium] (%) (the volume densities of the cardiac myocyte and interstitium), and Nv[myocyte] (1/mm3) (the numerical density of the cardiac myocytes) by the dissector method. The total number of myocytes (N[myocyte]) and the mean volume of the myocytes (V[myocyte]) were also determined. The differences were tested by the Mann-Whitney non-parametric test. RESULTS: The cardiac weight increased of 1.95 to 9.1 g, the Vv[myocyte] decreased from 85.18 to 77.78% and the Vv[interstitium] increased from 14.83 to 22.22%. The Nv[myocyte] decreased from 68.86 x 10(4) to 57.40 x 10(4)/mm3. The V[myocyte] increased from 1214.38 to 1412.31 microns3 and the N[myocyte] increased from 1.36 x 10(9) to 5.06 x 10(9) myocytes. These differences were statistically significant (p < 0.05). CONCLUSION: These results suggest the development of the myocardium at the end of the fetal human period as being mainly hypertrophic to the myocyte and the cardiac interstitium.

Miocárdio fetal humano. Proliferação do miócito e desenvolvimento do interstício cardíaco nos dois últimos trimestres gestacionais / Fetal Human Myocardium. Proliferation of the Myocytes and Development of the Cardiac Interstitium in the Last Two Gestational Trimesters

PURPOSE: To determine prenatal myocardial quantitative changes by using stereology. METHODS: Twenty-six human fetuses were studied (16 in the 2nd trimester and 10 in the 3rd trimester). The hearts were dissected, weighted, fixed in the Bouin's solution for 12 h, embedded in paraplast, sectioned and stained by HE and trichrome of Gomori. Ten random microscopic fields were analyzed by heart. The following parameters were studied: Vv[myocyte] and Vv[interstitium] () (the volume densities of the cardiac myocyte and interstitium), and Nv[myocyte] (1/mm3) (the numerical density of the cardiac myocytes) by the dissector method. The total number of myocytes (N[myocyte]) and the mean volume of the myocytes (V[myocyte]) were also determined. The differences were tested by the Mann-Whitney non-parametric test. RESULTS: The cardiac weight increased of 1.95 to 9.1 g, the Vv[myocyte] decreased from 85.18 to 77.78and the Vv[interstitium] increased from 14.83 to 22.22. The Nv[myocyte] decreased from 68.86 x 10(4) to 57.40 x 10(4)/mm3. The V[myocyte] increased from 1214.38 to 1412.31 microns3 and the N[myocyte] increased from 1.36 x 10(9) to 5.06 x 10(9) myocytes. These differences were statistically significant (p < 0.05). CONCLUSION: These results suggest the development of the myocardium at the end of the fetal human period as being mainly hypertrophic to the myocyte and the cardiac interstitium.