Fasting induced cytoplasmic Fto expression in some neurons of rat hypothalamus.

Fat mass and obesity associated protein (Fto) is a nucleic acid demethylase, with a preference for thymine or uracil, according to the recent structural data. This fact suggests that methylated single-stranded RNA, rather than DNA, may be the primary Fto substrate. Fto is abundantly expressed in all hypothalamic sites governing feeding behavior.

The effect of vasopressin 1b receptor (V1bR) blockade on HPA axis activity in rats exposed to acute heat stress.

Thermal stressors such as low and high ambient temperature elicit an abundance of neuroendocrine responses including activation of the hypothalamo-pituitary-adrenal (HPA) axis and arginine vasopressin (AVP) release. The exposure to heat is a particularly interesting model for studying AVP action because this kind of stressor represents not only an unpleasant experience but also a threat to osmotic homeostasis. As AVP has long been recognized as a hormone involved in the modulation of HPA axis activity, the aim of this study was to elucidate the role of AVP in acutely heat-exposed rats using Nelivaptan, a selective vasopressin 1b receptor (V1bR) antagonist.

Cholecystokinin-producing (I) cells of intestinal mucosa in dexamethasone-treated rats.

The aim of this study was to investigate the morphological, immunohistochemical and ultrastructural changes of cholecystokinin-producing (I) cells of gastrointestinal mucosa in dexamethasone-treated rats (D). After 12-daily intraperitoneal administration of 2mg/kg dexamethasone, rats developed diabetes similar to human diabetes mellitus type 2. The mean diameter of the duodenum was significantly decreased due to significant reduction of volume fraction and profile area of lamina propria.

The effect of acute heat exposure on rat pituitary corticotroph activation: the role of vasopressin.

The increased ambient temperature affects the function of hypothalamic-pituitary-adrenal (HPA) axis. Since the correlation among vasopressin (VP), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) responses to various stressors have been long recognized, the aim of this study was to reveal the aforementioned hormones production and morphology of the pituitary gland after exposure to acute heat. Rats were exposed to high ambient temperature (38 °C) for 20 or 60 minutes.

The effect of ascorbate supplementation on the activity of antioxidative enzymes in the rat hypothalamus and adrenals.

We investigated the effect of vitamin C on the oxidative status in the hypothalamus and adrenal glands of rats supplemented by its two doses over a four-week period. The results obtained have shown that vitamin C exerts effects which are tissue specific. In hypothalamus, it decreased the activity of copper zinc superoxide dismutase (CuZnSOD), the concentration of hydrogen peroxide (H2O2), as well as the activity of catalase and the level of lipid peroxidation, thus causing effects which are obviously antioxidative.

Effect of various stressors on the blood ACTH and corticosterone concentration in normotensive Wistar and spontaneously hypertensive Wistar-Kyoto rats.

The role of the sympathetic nervous system (SNS) and the hypothalamo-pituitary-adrenal (HPA) axis in the stress response is well documented. The imbalance in a central and peripheral SNS activity accompanied by the HPA hyperresponsivity has been observed in essential and experimental hypertension. The spontaneously hypertensive rats (SHR) are extensively used in studying mechanisms of the essential hypertension.

Serotonin-producing enterochromaffin (EC) cells of gastrointestinal mucosa in dexamethasone-treated rats.

The aim of our study was to investigate the morphological, immunohistochemical and ultrastructural changes of rat serotonin-producing enterochromaffin (EC) cells of gastrointestinal mucosa in dexamethasone-treated rats (D). After 12-daily intraperitoneal administration of 2 mg/kg dexamethasone, rats developed diabetes similar to human diabetes type 2. Stomach, small and large intestines were examined.

Effect of the acute crowding stress on the rat brown adipose tissue metabolic function.

Our previous results have shown that metabolic and thermal stressors influence interscapular brown adipose tissue (IBAT) metabolic activity by increasing oxygen consumption and, consequently, altering the toxic reactive oxygen species (ROS) production and the antioxidative system activity. Since there is not enough evidence about the effect of psychosocial stressors on these processes, we studied the effect of acute crowding stress on the IBAT and hypothalamic monoamine oxidase (MAO) activity as well as IBAT antioxidative enzymes, manganese (MnSOD), copper-zinc superoxide dismutase (CuZnSOD) and catalase (CAT), as the relevant indicators of IBAT metabolic alternations under the stress exposure and the returning of animals to control conditions. The results indicated that acute crowding stress did not change the hypothalamic and IBAT MAO activities, the generation of ROS and, consequently, the IBAT CuZnSOD and CAT activities.

Total monoamine oxidase activity in the hypothalamus, ovary and uterus of rats with an extreme number of ovarian corpora lutea.

The activity of total monoamine oxidase (MAO) in the rat ovary and uterus fluctuates significantly under various physiological conditions. We analyzed total MAO activity in the hypothalamus, uterus and ovary in adult rats, having an extreme number of corpora lutea (hyperluteinized ovaries) resulting from the mechanical lesions in the posterior hypothalamic region of neonatal rats. Total MAO activity in the hypothalamus (30.