Protective Effects of Voluntary Exercise on Hepatic Fat Accumulation Induced by Dietary Restriction in Zucker Fatty Rats.

Weight control based on dietary restriction (DR) alone can cause lipid metabolic failure and progression to fatty liver. This study aimed to investigate the effect of exercise on preventing DR-induced hepatic fat accumulation in Zucker fatty (ZF) rats by focusing on the relationship between adipose tissue lipolysis and hepatic fat uptake. Six-week-old male ZF rats were randomly assigned to obese, DR, or DR with exercise (DR + Ex) groups.

Characterization of fat metabolism in the fatty liver caused by a high-fat, low-carbohydrate diet: A study under equal energy conditions.

The pathology of fatty liver due to increased percentage of calories derived from fat without increased overall caloric intake is largely unclear. In this study, we aimed to characterize fat metabolism in rats with fatty liver resulting from consumption of a high-fat, low-carbohydrate (HFLC) diet without increased caloric intake. Four-week-old male Sprague-Dawley rats were randomly assigned to the control (Con) and HFLC groups, and rats were fed the corresponding diets ad libitum.

Effects of habitual exercise and dietary restriction on intrahepatic and periepididymal fat accumulation in Zucker fatty rats.

Background: Habitual exercise and dietary restriction are commonly recommended to prevent or ameliorate obesity and lifestyle-related diseases, including fatty liver. This study investigated the effects of habitual exercise and dietary restriction on hepatic triglyceride (TG) levels, serum leptin levels, and histological adipocyte size in periepididymal adipose tissue from Zucker fatty (ZF) rats.

Methods: Six-week-old male ZF rats were randomly assigned to one of three groups: sedentary (Sed), sedentary and dietary restriction (Sed + DR), and training and dietary restriction (Tr + DR).

Filamentous structure of the external surface of abalone eggs revealed by quick-freeze deep-etch technique.

The external surface of abalone eggs was examined by thin section and quick-freeze, deep-etch electron microscopy. In thin sections, networks of fine filaments were found interconnecting the adjacent microvilli on the surface of unfertilized eggs. Quick-freeze, deep-etch electron microscopy revealed the three-dimensional structure of these networks of filaments on the external surface of the egg.

Organization of Actin Filaments in the Axial Rod of Abalone Sperm Revealed by Quick Freeze Technique: (actin filaments/abalone sperm/quick-freeze deep-etch/freeze-substitution/cytoskeleton).

An axial rod in abalone (Haliotis discus) sperm is a structure composed of a bundle of actin filaments, which elongates anteriorly to form the acrosomal process during the acrosome reaction. The ultrastructure of the actin filament bundle constituting the axial rod was examined using quick freeze technique followed by either freeze-substitution or deep-etch electron microscopy. Thin sections of quick freeze and freeze-substituted sperm revealed that the actin filaments in the axial rod are hexagonally packed in a paracrystalline array through its almost entire length with an average center-to-center spacing of 12 nm.

Coiled Filamentous Structure in the Sperm Acrosome of Gastropoda, Sulculus aquatilis and Turbo cornutus: (acrosome reaction/coiled filaments/gastropoda/cytoskeleton/fertilization).

A helically coiled filamentous structure, termed the truncated cone originally identified in Haliotis discus, was demonstrated to exist in the apex of the acrosome subjacent to the outer acrosomal membrane of the sperm in two species of Gastropoda, Sulculus aquatilis and Turbo cornutus. Thin section and whole mount preparations revealed that in intact sperm this filamentous structure consisted of about 12 helically arranged filaments with a diameter of 10-12 nm which were tightly packed in a truncated shape. This truncated cone elongated anteriorly from the acrosomal opening and transformed into a cylinder which closely surrounds the acrosomal process during the acrosome reaction.

Distribution of Intramembrane Particles and Its Changes during the Acrosome Reaction in Spermatozoa of the Japanese Abalone: (abalone sperm/acrosome reaction/membrane particle/freeze-fracture).

The distribution of intramembrane particles in the plasma and acrosomal membranes of sperm of the Japanese abalone, Haliotis discus, and its changes during the acrosome reaction were studied by the freeze-fracture replica technique. The P face of the plasma membrane covering the acrosome has sparse membrane particles except in the apical region, which includes the trigger and 'truncated cone' regions. Large particles with an average diameter of 10 nm are located in this apical region.

Ultrastructural Changes of the "Truncated Cone" during the Acrosome Reaction in Japanese Abalone Spermatozoa: (abalone/acrosome reaction/truncated cone/ultrastructure).

An electron-dense structure termed the "truncated cone" covers the apical surface of the acrosomal contents except for the trigger region in Haliotis discus spermatozoa. The truncated cone, having a slant height of 0.3 μm and diameters of circular top and base of 0.

Fine Structural Changes in the Acrosome Reaction of the Japanese Abalone, Haliotis disus: (abalone/sperm/acrosome reaction/ultrastructure).

The spermatozoon of the Japanese abalone, Haliotis discus, and its structural changes during the acrosome reaction were observed by electron microscopy. The spermatozoon has a huge acrosome in the shape of a hanging bell or a forefinger with a deep fossa at the posterior end being filled with a bundle of microfilaments. The membranes of the acrosomal apex, the so-called trigger region, are structurally discernible from those of other acrosomal regions.