Influence of cold exposure on dopamine content in rat brown adipose tissue.

Cold exposure produces a large increase in rat brown adipose tissue (BAT) dopamine (DA) content. This increase is rapid (30 min of cold are sufficient to produce a maximal effect), and can be detected at different ages (from birth to adulthood). Cold also greatly increases DA turnover rate in BAT.

[Quantitative histo-enzymological study of delta 5-3 beta-hydroxysteroid dehydrogenase activity in rat testis during the perinatal period. Relation with testicular crisis in the newborn rat].

The purpose of the present work was to determine if the neonatal testosterone surge in the rat (between 0 and 6 h after birth) was coincident with the histological and histochemical changes in the neonatal period. The histological study shows a decrease in the number of gonocytes and cells in mitosis. These observations are in good agreement with the results obtained by other authors.

Intermale aggression in mice: does hour of castration after birth influence adult behavior?

In the mouse, perinatally present testicular androgens promote the development of the propensity for adult intermale aggression. In the newborn male mouse plasma testosterone more than doubles during the first 2 h after birth and then falls rapidly to remain relatively low for the remainder of the 24-h period after birth. To study whether this surge in plasma testosterone influences aggressiveness we castrated some male mice within 1 h after birth i.

Striatal dopamine metabolism is differentially affected by insulin according to the genotype in Zucker rats: a microdialysis study.

The genetically obese Zucker rat presents several abnormalities related to insulin and brain monoamines, which may play a role in its impaired regulation of food intake and body weight. In a previous study, the possible insulin-monoamine interplay was investigated by measuring brain monoamine and metabolite levels in the three genotypes of the Zucker strain. In addition to the expected results, insulin had a particular effect on striatal dopamine (DA) release, regardless of ponderal status and genotype.

[Variations in the testicular response to HCG during the perinatal period in the rat: influence of estrogens].

The variations of the testicular responsiveness to hCG and the implication of the maternal estrogens in the functioning of the testes were studied in the perinatal male rat. Male rat fetuses treated with hCG at the end of gestation failed to show an increase in serum testosterone (T). The lack of testicular responsiveness to hCG in the fetus is neither due to anesthesia nor to a blocking effect of estrogens directly on the testes.