The effect of the aerobic training on morphological and histochemical characteristics of tibial anterior muscle in rats fed with high fat diet

The aim of this study was to investigate the effect of high fat diet and different frequencies of swimming programs in the tibial anterior muscle in male Wistar rats. In conclusion, the aerobic training during two days/week and five days/week caused injuries in muscle fibers and the high fat diet did not cause statically significant results compared to normal diet.

El objetivo de este estudio fue investigar el efecto de dietas ricas en grasas y diferentes frecuencias de natación, en el músculo tibial anterior, de ratas machos Wistar. El entrenamiento aeróbico, durante dos y cinco días por semana, causó lesiones en las fibras musculares y la dieta alta en grasa, no produjo resultados estadísticamente significativos, en comparación con la dieta normal.

Down-regulation of the cardiac sarcoplasmic reticulum ryanodine channel in severely food-restricted rats

We have shown that myocardial dysfunction induced by food restriction is related to calcium handling. Although cardiac function is depressed in food-restricted animals, there is limited information about the molecular mechanisms that lead to this abnormality. The present study evaluated the effects of food restriction on calcium cycling, focusing on sarcoplasmic Ca2+-ATPase (SERCA2), phospholamban (PLB), and ryanodine channel (RYR2) mRNA expressions in rat myocardium. Male Wistar-Kyoto rats, 60 days old, were submitted to ad libitum feeding (control rats) or 50 percent diet restriction for 90 days. The levels of left ventricle SERCA2, PLB, and RYR2 were measured using semi-quantitative RT-PCR. Body and ventricular weights were reduced in 50 percent food-restricted animals. RYR2 mRNA was significantly decreased in the left ventricle of the food-restricted group (control = 5.92 ± 0.48 vs food-restricted group = 4.84 ± 0.33, P < 0.01). The levels of SERCA2 and PLB mRNA were similar between groups (control = 8.38 ± 0.44 vs food-restricted group = 7.96 ± 0.45, and control = 1.52 ± 0.06 vs food-restricted group = 1.53 ± 0.10, respectively). Down-regulation of RYR2 mRNA expressions suggests that chronic food restriction promotes abnormalities in sarcoplasmic reticulum Ca2+ release.

Histological characterization of Sticholecitha serpentis Prudhoe, 1949 (Digenea, Bieriidae, Sticholecithinae), parasite of Bothrops moojeni Hoge, 1966 (serpentes, viperidae)

The aim of this study was to evaluate the morphology of the species Sticholecitha serpentis Prudhoe, 1949 by means of histological procedures. Helminths were previously fixed in Railliet & Henry solution, uncompressed and were included in 2-hydroxyethyl-methacrylate. Longitudinal and transverse serial sections with a 4-mm thickness were performed in a microtome (Leica RM 2165), stained with haematoxylin-eosin and then analyzed in a computerized image analysis system (Qwin Lite 2.5, Leica). Structures of systematic value, such as oral sucker, acetabulum, prepharynx, pharynx, esophagus, intestinal caeca, vitelline glands, ovary, uterus, cirrus pouch and testicles were described. Structures that were poorly visible in total preparations were also observed and described, such as efferent ducts, ejaculatory duct, prostate, seminal vesicle, seminal receptacle, Laurer’s channel, Mehlis’ gland, vitelline ducts, metraterm, genital atrium, digestive glands and excretory vesicle. We demonstrated that histological analysis can supply important data regarding the morphological characterization of S. serpentis and will be able to contribute to systematic studies of trematodes

Histochemical fiber types of oesophageal striated muscle in synbranchus marmoratus (Bloch, 1795-pisces, synbranchidae)

Las características histoquímicas de la musculatura externa en el esófago de Synbranchus marmoratus, han sido evidenciadas notándose que no existe una división nítida entre las capas musculares circular externa e interna. Las fibras que integran estas capas se caracterizan por tener una actividad oxidativa media y alta ante la reacción enzimática de NADH-TR. La actividad m-ATPasa con preincubaciones alcalinas fue alta en la mayoría de las fibras. Además fibras de pequeño tamaño en la región interna de la musculatura presentaron baja actividad m-ATPasa y alta actividad oxidativa