Hepatic effects of long-term tamoxifen administration to cycling female rats.

The metabolic implications of tamoxifen (TAM) used as preventive therapy of young premenopausal women with high risk of breast cancer is unknown. To unravel this problem, an animal model of long-term TAM administration to cycling young adult female rats was used to evaluate its effects in the liver. Body weight and food consumption were monitored, and at the end of the study, both parameters were lower in TAM-treated rats.

The 17beta-hydroxysteroid dehydrogenase 4: Gender-specific and seasonal gene expression in the liver of brown trout (Salmo trutta f. fario).

Previously, it was documented that liver peroxisomes display seasonal size changes in the adult Salmo trutta fario, especially in females (and negatively correlated with ovary maturation). It was then hypothesized that decreases in peroxisome size could be paralleled by changes in peroxisomal beta-oxidation and estradiol catabolism actions. The 17beta-hydroxysteroid dehydrogenase 4 has been portrayed as playing an important role in both processes.

Seasonal and gender variation of peroxisome proliferator activated receptors expression in brown trout liver.

PPAR isotypes have been previously identified in the teleost brown trout (Salmo trutta f. fario) and their organ distribution pattern established. Being that the liver is a vital metabolic organ presenting expression of all isotypes and also knowing that estrogens/estrogen receptors seem to interact with PPARs, we hypothesized that the latter may very well change seasonally.

Light and electron microscopy studies of the oesophagus and crop epithelium in Aplysia depilans (Mollusca, Opisthobranchia).

The oesophagus and crop epithelium of Aplysia depilans consist in a single layer of columnar cells with apical microvilli, and some of them also possess cilia. Cell membrane invaginations, small vesicles, multivesicular bodies and many dense lysosomes were observed in the apical region of the cytoplasm. In most cells, a very large lipid droplet was observed above the nucleus and a smaller one was frequently found below the nucleus; glycogen granules are also present.

Identification and organ expression of peroxisome proliferator activated receptors in brown trout (Salmo trutta f. fario).

Although widely studied in mammals, little information about fish peroxisome proliferator activated receptors (PPARs) is yet available. As a baseline for future studies, the three PPAR isotypes were identified in brown trout (Salmo trutta f. fario) and their organ distribution pattern was established.

Stomach of Aplysia depilans (Mollusca, Opisthobranchia): a histochemical, ultrastructural, and cytochemical study.

We report the results of a morphological, histochemical, and cytochemical characterization of the Aplysia depilans stomach, an organ little studied in opisthobranchs. Very thin ciliated cells with microvilli on their apical surfaces are predominant in the epithelium lining the lumen of the stomach. Many lysosomes with a strong arylsulphatase activity were present in the apical regions of these cells that could also contain some lipid droplets and glycogen.