Propranolol-like action of amiodarone. An electronmicroscopic study in rats under cold stress.

The cold stress leads to increased levels of catecholamines, of their precursors and metabolites, with increased oxygen consumption by the myocardium. Atrial cardiomyocytes of amiodarone-treated rats, previously stressed by cold, showed a marked decrease of the morphological alterations observed in the animals submitted to cold stress without amiodarone protection. Such results indicate, at the subcellular level, that amiodarone could improve cardiac function by a propranolol-like action when there is heart failure, a condition in which there is a high level of catecholamine.

Subcellular alterations of cardiac fibers in rats subjected to hypothyroidism.

Subcellular changes of the atrial cardiomyocytes of rats submitted to hypothyroidism caused by administration of 1 mg/100 g of body weight of propylthiouracil showed a) swollen mitochondria and lysis of their cristae; b) myofibrils with marked heterogeneity of patterns, some exhibiting rupture and loss of continuity of their myofilaments; c) lesser concentration of atrial granules in the perinuclear area; d) abundant granular interstitial tissue and collagen separating the myofibrils.

Action of propranolol on the atrial cardiomyocytes of rats submitted to cold stress.

Subcellular changes of the atrial cardiomyocytes of rats caused by cold showed a) altered mitochondria with edema and lysis of crests; b) myofibrils with marked heterogeneity of patterns and ruptures, c) myofilaments disarrangement, partial necrosis and disintegration of filaments, d) lesser concentration of atrial granules in the perinuclear area. Atrial muscle fibers of propranolol-treated rats previously stressed by cold showed a marked decrease of the morphological alterations observed in the animals submitted to cold stress without propranolol protection.

Topochemistry of blood cells of the Gallus domesticus (Aves, Galliforme).

Blood smears of both male and female chicken Gallus domesticus were analysed by using the following topochemical methods: a) Periodic acid-Schiff (PAS) for glycogen. b) Mercury-bromophenol blue for protein. c) O-Toluidine for myeloperoxidase. d) Sudan black B for lipid. The PAS reaction revealed glycogen in the cytoplasm of all thrombocytes and in a few heterophils. The presence of proteins was evidenced in all types of cells. However variation in the intensity of staining of protein granules was observed in the fusiform structures of the heterophils. A negative reaction for myeloperoxidase was found in all cells. Although some evidence of myeloperoxidase activity was show in the polymorphonuclears it was not enough to ascertain a positive reaction. Lipids were detected in the cytoplasm of few heterophils, eosinophils and monocytes.

Topochemistry of blood cells of the Gallus domesticus (Aves, Galliforme)

Extensöes de sangue periférico de aves (macho e fêmea), foram submetidas a um estudo topoquímico que permitiu as seguintes conclusöes: com o PAS, a presença de glicogênio nos trombócitos e alguns heterófilos; com o azul de bromofenol (proteína) positividade em todos os elementos celulares, com intensa reatividade da regiäo equatorial dos grânulos fusiformes de heterófilos; com o método da orto-toluidina-água oxigenada (mieloperoxidase), reatividade discutível nos polimorfonucleares e negativa nos demais tipos de células e com Sudan black (lipídios) uma positividade em alguns heterófilos, eosinófilos e monócitos

Atividade de algumas enzimas do musculo cardíaco do rato albino durante o estresse agudo. Estudo histoquímico / Activity of some enzymes of cardiac muscle of albino rats during acute stress. Histochemical study

Foram estudadas as alteracoes histoquimicas relativas ao grau de positividade da desidrogenase succinica, da desidrogenase lactica, da adenosina trifosfatase e da aldolase da fibra cardiaca do rato albino em estresse agudo. Os resultados obtidos indicam que, durante o estresse agudo, ha maior demanda metabolica da fibra cardiaca com aumento do metabolismo oxidativo aerobico, nao ocorrendo hipoxia

Variacoes numericas das mitocondrias nos leiomiocitos do miometrio da rata no estro, no 7o. e 20o. dias da prenhez. / Numerical evaluation of mitochondria of myometrial leiomyocites of female rat in the estro at 7th and 20th day of pregnancy

A avaliacao numerica das mitocondrias dos leiomiocitos de ratas albinas no estro, entre o 7o. e 20o. dia da gravidez, foi efetuada pelo microscopio otico. Os resultados estatisticos mostraram que o numero de mitocondrias tende a diminuir com a evolucao da gravidez

Electron microscopy of lamellated osmiophilic bodies in granular pneumocytes of the toad (Bufo icterus icterus) in an advanced stage of dehydration and after rehydration.

The effects of body dehydration on the ultrastructural pattern of lamellated osmiophilic bodies of granular pneumocytes of toads were investigated until almost complete absence of these bodies after 40 per cent body weight loss. The presence of lamellated osmiophilic bodies after rehydration would strongly indicate that water has a great influence upon the secretion of these structures.