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.

Time-dependent effects of starvation on serum, pituitary and hypothalamic leptin levels in rats.

Leptin is produced by white adipose tissue and other cell types and is involved in both short- and long-term appetite control. Here we studied effects of starvation on serum, pituitary and hypothalamic levels of leptin during 72 h period. Each of the starved groups was sacrificed simultaneously with the group of ad libitum fed animals.

Ivan Djaja (Jean Giaja) and the Belgrade School of Physiology.

The founder of physiology studies in the Balkans and the pioneer of research on hypothermia, Ivan Djaja (Jean Giaja) was born 1884 in L'Havre. Giaja gained his PhD at the Sorbonne in 1909. In 1910 he established the first Chair of Physiology in the Balkans and organized the first Serbian Institute for Physiology at the School of Philosophy of the University of Belgrade.

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.

Distinct and combined effects of acute immobilization and chronic isolation stress on MAO activity and antioxidative protection in the heart of normotensive and spontaneously hypertensive rats.

The heart is an organ especially sensitive to the sympathetic overstimulation and therefore to the influence of stressors and hypertension. The aim of the present study was to investigate the effect of two distinct types of stressors, acute immobilization (2 h) and chronic isolation stress (21 days), as well as their combined effect on the activity of monoamine oxidase (MAO), superoxide dismutase, catalase (CAT) and the ascorbic acid (AA) content in the heart of normotensive and spontaneously hypertensive rats (SHR). The results obtained show that in basal conditions heart MAO and CAT activity (p < 0.

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.

Involvement of nitric oxide in noradrenaline-induced changes in the activity of antioxidant enzymes and lipid peroxidation in rat brown adipose tissue and heart.

The effect of exogenous noradrenaline (NA) (1.6 mg x kg(-1) i.p.

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.

The activities of antioxidant enzymes and monoamine oxidase and uncoupling protein 1 content in brown fat of hypo- and hyperthyroid rats.

We have studied the activities of antioxidant enzymes (AOE), namely, copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), and catalase (CAT), and the activity of catecholamine-degrading enzyme monoamine oxidase (MAO) and uncoupling protein 1 (UCP1) content in brown fat (BF) of hypo- and hyperthyroid rats. We found that hypothyroidism decreased BF UCP1 content and increased MAO, MnSOD, and CAT activities. T3 increased UCP1 content and MnSOD activity and decreased CuZnSOD, MAO, and CAT activities, while T4 significantly altered (decreased) only CAT activity.

Effect of cold exposure on serum DBH and interscapular brown adipose tissue MAO activity in hypothyroid T3- and T4-treated rats.

As the indicators of sympathetic nervous system (SNS) function, the activity of serum dopamine-beta-hydroxylase (DBH) and interscapular brown adipose tissue (IBAT) monoamine oxidase (MAO) were examined in rats that were chemically thyroidectomized (TX), treated with thyroid hormones, and exposed to cold (4 degrees C). In TX animals, body temperature (bt) significantly decreased, and relative IBAT mass increased as compared with control, euthyroid animals, independent of the ambient temperature. The bt fall in TX cold-exposed animals was more severe, provoking hypothermia after 4 h.

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.

Different activation of ACTH and corticosterone release in response to various stressors in rats.

The aim of this study was to investigate the reaction of the hypothalamo-pituitary-adrenocortical (HPA) system to various stressors (fasting, crowding, cold and heat) by measuring blood ACTH and corticosterone (CORT) concentration as well as the cholesterol (CHOL) content in the adrenals. To examine the effects of stress termination, the rats were returned and kept under control conditions for the same period as that of stress duration (supposed recovery period). According to our results HPA system was activated by all the stressors applied.

Thyroxine and tri-iodothyronine differently affect uncoupling protein-1 content and antioxidant enzyme activities in rat interscapular brown adipose tissue.

The activity of the antioxidant enzymes copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and catalase (CAT), as well as mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) activity, uncoupling protein-1 (UCP1) content, catecholamine degrading enzyme monoamine oxidase (MAO) activity and malonyl dialdehyde (MDA) concentration were studied in rat interscapular brown adipose tIssue (IBAT). Rats were treated with either thyroxine (T4) or tri-iodothyronine (T3) for five days and then exposed to cold (4 degrees C, 24 h) or housed at room temperature (22 degrees C). Under basal conditions, T3 treatment significantly increased UCP1 content and MnSOD activity whereas CuZnSOD, CAT and MAO activities were significantly decreased.

The activity of antioxidant enzymes and the content of uncoupling protein-1 in the brown adipose tissue of hypothyroid rats: comparison with effects of iopanoic acid.

The activity of antioxidant enzymes, copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and catalase (CAT), as well as that of the mitochondrial FAD-dependent alpha-glycerophosphate dehydrogenase (alpha-GPD) in the rat interscapular brown adipose tissue (IBAT) were studied after the treatment with methimazole (MMI) for three weeks or with iopanoic acid (IOP) for five days. Besides, the mitochondrial concentration of uncoupling protein-1 (UCP-1) and the activity of catecholamine degrading enzyme monoamine oxidase (MAO) in the IBAT as well as the activity of the catecholamine synthesizing enzyme, dopamine beta-hydroxylase (DBH) in rat serum were examined. Judging by the significantly enhanced level of serum DBH, which is an index of sympathetic activity, and that of IBAT MAO, the increase in MnSOD and CAT activities in the IBAT of hypothyroid (MMI-treated) rats seems to be due to elevated activity of sympathetic nervous system (SNS).

Effect of fasting and refeeding on the activities of monoamine oxidase and antioxidant enzymes in rat hypothalamus and brown adipose tissue.

Fasting for 48 h and the same period of recovery induced by 48 h refeeding increased rat hypothalamic monoamine oxidase (MAO) activity. However, in the interscapular brown adipose tissue (IBAT), only refeeding induced a significant elevation of the enzyme activity. As far as hypothalamic antioxidative enzymes are concerned, the copper zinc superoxide dismutase (CuZnSOD) activity was decreased in refed rats only.

Chronic effect of insulin on monoamine oxidase and antioxidant enzyme activities in the rat brainstem.

It was shown that hydrogen peroxide (H2O2) is a possible intracellular second messenger in specific insulin action. Because its concentration in the cell depends on the activity of both antioxidant enzymes and monoamine oxidase (MAO), we studied the influence of different insulin doses (0.4 and 4.

Activities of antioxidant enzymes and monoamine oxidase-A in the rat interscapular brown adipose tissue: effects of insulin and 6-hydroxydopamine.

The effects of different doses of insulin (INS) (0.4 or 4.0 IU/kg body mass, i.

The effects of continuous light and darkness on the activity of monoamine oxidase A and B in the hypothalamus, ovaries and uterus of rats.

For assessing monoamine oxidase (MAO-A and -B) activities in the hypothalamus, ovaries and uterus, mature female rats were exposed to either continuous light or dark over 6 weeks. Confirming previous studies, continuous light induced constant estrus in all animals. The majority of animals kept under continuous dark during the six weeks remained mostly in diestrus with estrus appearing sporadically.

The effect of glucocorticoids on the activity of monoamine oxidase, copper-zinc superoxide dismutase and catalase in the rat hypothalamus.

The activities of biogenic amine deaminating enzymes, monoamine oxidase (MAO), types A and B, copper-zinc superoxide dismutase (CuZnSOD) and hydrogen peroxide (H2O2) scavenging enzyme, catalase, were studied in the hypothalamus of rats treated with dexamethasone (DEX) and corticosterone (CORT) for 2 and 7 days. Only chronic treatment (7 days) with both glucocorticoids (DEX -0.2 mg/kg b.

The effect of glucocorticoids on the activity of monoamine oxidase and superoxide dismutase in the rat interscapular brown adipose tissue.

The effect of dexamethasone (DEX) and corticosterone (COR) on the activity of monoamine oxidase (MAO), copper-zinc superoxide dismutase (CuZn SOD) and manganese superoxide dismutase (Mn SOD) in the rat interscapular brown adipose tissue (IBAT) were studied. DEX (1 mg/kg, i.p.