Nicotinic acid attenuates amyloid β-induced mitochondrial dysfunction and inhibits the mitochondrial pathway of apoptosis in differentiated SH-SY5Y cells.

Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by progressive memory loss and behavioral disorders. The excessive accumulation of amyloid β (Aβ) and the formation of neurofibrillary tangles (NFTs) damage synaptic connections and the death of neurons. However, the underlying mechanisms of pathogenesis of AD remain unclear.

Exogenous orexin-A downregulates luteinizing hormone secretory activity in prepubertal female rats.

Introduction: Orexin-A is a neuropeptide synthesized in the lateral hypothalamus. Orexin-A immunoreactive fibres overlap distribution with GnRH neurons. In adult rats, orexin A is known to affect LH secretion via GnRH release modulation.

All-trans-retinoic acid ameliorates atherosclerosis, promotes perivascular adipose tissue browning, and increases adiponectin production in Apo-E mice.

All-trans-retinoic acid (atRA), an active metabolite of vitamin A, exerts a potential role in the prevention of cardiovascular diseases. It has been shown that atRA ameliorates atherosclerosis while the exact mechanism underlying this protection remains unknown. This study investigated the influence of atRA on insulin resistance (IR), atherosclerosis, and the process of perivascular adipose tissue (PVAT) browning.

The Effects of Alpha-Linolenic Acid on the Secretory Activity of Astrocytes and Amyloid-Associated Neurodegeneration in Differentiated SH-SY5Y Cells: Alpha-Linolenic Acid Protects the SH-SY5Y cells against Amyloid Toxicity.

Alzheimer's disease (AD) is the most common neurodegenerative disorder. Amyloid - (A-) induced mitochondrial dysfunction may be a primary process triggering all the cascades of events that lead to AD. Therefore, identification of natural factors and endogenous mechanisms that protect neurons against A toxicity is needed.

The effect of valproate (VPA) treatment on inositol phosphates (IPs) accumulation in non-stimulated and GnRH-treated female rat anterior pituitary cells in vitro.

Objective: Mechanism(s) responsible for VPA-induced effects on reproductive axis activity are not fully recognized. Previously we reported that VPA suppressed only GnRH-stimulated but not the basal LH release from rat anterior pituitary (AP) cells in vitro. Since the inhibitory effect of VPA was exerted only in GnRH-activated cells, potential VPA impact on GnRH-R-coupled IP3/PKC signaling could not be excluded.

The evaluation of estradiol and leptin action on the activity of the somatotropic and gonadotropic axes in peripubertal female rats.

Objective: Available data suggest that estrogens and leptin play a role in the control of the pubertal process. In humans and some mammal species the increase of the activity of gonadotropic axis accompanies the decrease in the rate of growth at puberty. The effect of 17β-estradiol and/or leptin administration on the somatotropic and gonadotropic axes was studied using prepubertal female rats as an animal model.

Evaluation of orexin A activity on LH and FSH release from primary culture pituitary cells in immature and mature female rats.

Objectives: Orexin A (OxA) is a regulatory neuropeptide which is involved in the control of various autonomic and neuroendocrine functions. It regulates sleep-wake cycle, food intake and modulates the hypothalamic and pituitary hormones secretion. Orexin A acts through two types of receptors, which proved to exist in the pituitary.

Valproate inhibits GnRH-induced gonadotropin release from anterior pituitary cells of male rat in vitro.

Objective: Valproate (VPA) a potent antiepileptic drug has been claimed to induce reproductive disturbances in men. Long-term VPA treatment can affect sperm morphology and induce testicular atrophy in non-epileptic rats. It has been reported that VPA reduced testosterone secretion stimulated by hCG in isolated rat Leydig cells.

The influence of cocaine-amphetamine regulated transcript (CART) on pituitary hormones, corticosterone and leptin levels in starved rats.

Objective: CART is involved in the control of food intake and hormonal secretion. We aimed to evaluate the effects of CART on hormonal profile in starved rats.

Methods: Study group included 100 male rats.

Involvement of the cocaine-amphetamine regulated transcript peptide (CART 55-102) in the modulation of rat immune cell activity.

Objective: Cocaine-amphetamine regulated transcript peptides (CART) belong to a neuropeptide family expressed in the central nervous system, especially in the hypothalamus, and also in peripheral tissues. The physiological functions of CART include modulation of pituitary hormone release, regulation of body weight, and the control of feeding behavior and metabolic activity. The reciprocal relationships between CART and immune system function have to be established.

Plasma beta amyloid and cytokine profile in women with Alzheimer's disease.

Alzheimer's disease (AD) belongs to a group of neurodegenerative disorders. It is characterized by irreversible and progressive memory loss accompanied with decline in other cognitive functions. At a microscopic level, the typical neuropathologic features, senile plaques and neurofibrillary lesions are found.

Controversial opinions on the role of cocaine and amphetamine-regulated transcript (CART) in prolactin release.

Cocaine and amphetamine regulated transcript (CART) is widely expressed in the central nervous system and in several endocrine organs. The physiological role of this peptide includes modulation of appetite control, energy expenditure, thermoregulation and hormone secretion. It has been suggested that CART influences prolactin (PRL) secretion both directly and indirectly.

A method for evaluation of activity of growth hormone-releasing hormone analogues.

Objective: It has been found that hGH-RH analogues with increased resistance to enzymatic degradation have a much higher potency than the native hGH-RH (1-29)-NH2 and have an ability to partially reverse growth hormone deficiencies.

The Aim: The aim of these studies was to elaborate a method which can be used for preliminary evaluation of new GH-RH analogues both from the point of view of their potency to release GH and enzymatic stability.

Method: Two highly active GH-RH analogues with increased resistance to trypsin-like enzymes, and hGH-RH(1-29)-NH2 used as a standard, in doses 1 nM, 10 nM, and 100 nM were added to pituitary rat cell culture, and medium was collected after 30, 60, 120 and 240 min.

The relationship between metabolic status and levels of adiponectin and ghrelin in lean women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is commonly associated with insulin resistance, obesity, dyslipidemia and hypertension. Adiponectin, an adipocyte-specific protein with important roles in glucose and lipid homeostasis, possesses antidiabetic and insulin-sensitizing properties. Ghrelin, a protein ligand for the growth hormone secretagog receptor, has been shown to stimulate food intake and to influence energy balance, insulin signaling and glucose metabolism.

PACAP 38 inhibits adiponectin release.

Background: Pituitary adenylate cyclase activating peptide (PACAP 38) is a neuropeptide with anti-inflammatory activity. Vasoactive intestinal peptide (VIP)/PACAP receptors are found in immune cells, endocrine glands and also in adipose tissue. Adiponectin is an adipocyte-derived protein hormone which possesses anti-inflammatory, antidiabetic and antiatherogenic properties.

Orexin A and its role in the regulation of the hypothalamo-pituitary axes in the rat.

Orexin A (OxA), a recently discovered neuropeptide, is synthesized mainly by neurons located in the posterolateral hypothalamus and is a 33 amino acid peptide with N-terminal pyroglutamyl residue and two inter-chain disulfide bonds. It is a potent agonist for both the orexin-1 (OxR1) and orexin-2 (OxR2) receptors. Orexin A and its receptors are widely distributed in the central nervous system (CNS) and peripheral organs suggesting the pleiotropic functions of this peptide.

The relationship between adiponectin levels and metabolic status in centenarian, early elderly, young and obese women.

Objectives: Adipose tissue secretes proteins which regulate energy metabolism and insulin sensitivity. Adiponectin possesses anti-diabetic, anti-atherogenic and insulin-sensitizing properties. To assess the prognostic factors in prolonged survival and the potential protective role of adiponectin in aging, we examined the release of adiponectin in relation to the metabolic status of centenarians, compared with young, early elderly and obese subjects.

Can PACAP-38 modulate immune and endocrine responses during lipopolysaccharide (LPS)-induced acute inflammation?

Pituitary adenylate cyclase-activating polypeptide (PACAP) shows a potential anti-inflammatory activity and interacts with the endocrine system. The aim of the present article was to evaluate the effects of PACAP38 on the endocrine and immune systems during acute inflammation. Rats used in the experiments, divided into four groups, were given intraperitoneal injection of, respectively 0.

PACAP 38 as a modulator of immune and endocrine responses during LPS-induced acute inflammation in rats.

The effect of PACAP 38 administration on neuroendocrine and immune parameters was examined in rats with LPS-induced peritonitis. Treatment with PACAP 38 alone did not influence the serum level of the cytokines and hormones examined, but significantly decreased immune cell activity. When administered together with LPS, PACAP 38 reversed its effect on immune and humoral parameters, causing a decrease in the serum concentrations of TNFalpha and corticosterone, and an increase in T4 and GH.

Evaluation of neuroendocrine status in longevity.

It is well known that physiological changes in the neuroendocrine system may be related to the process of aging. To assess neuroendocrine status in aging humans we studied a group of 155 women including 78 extremely old women (centenarians) aged 100-115 years, 21 early elderly women aged 64-67 years, 21 postmenopausal women aged 50-60 years and 35 younger women aged 20-50 years. Plasma NPY, leptin, glucose, insulin and lipid profiles were evaluated, and serum concentrations of pituitary, adrenal and thyroid hormones were measured.

Bombesin inhibits LH release in ovariectomized (OVX), estrogen primed rats.

Objective: Bombesin, 14-amino acid peptide, discovered in the gastrointestinal tract, is widely distributed in the central nervous system (CNS). The specific receptors of bombesin in the pituitary have been characterized. Bombesin plays an important role in the gastric and pancreatic secretion, in the mechanism of food intake, thermoregulation and in pituitary hormone secretion.

Direct effect of cortistatin on GH release from cultured pituitary cells in the rat.

Objective: Cortistatin (CST) is a 17-amino acid neuropeptide expressed mainly in the cortex and hippocampus. It is also found in the peripheral tissues such as the stomach, kidney, pancreas and the immune system. Two forms of cortistatin CST-17, CST-29 bind with high affinity all somatostatin (SS) receptor subtypes.

The effect of cocaine-amphetamine regulated transcript (CART) on the activation of the pituitary-adrenal axis.

Objective: It has been reported that the cocaine and amphetamine regulated transcript (CART) is widely expressed in the hypothalamic nuclei involved in the mechanism of hormonal secretion.

Research Methods: In order to evaluate the effect of CART on the activation of the pituitary-adrenal axis in the rat, CART (55-102) in a dose of 0.5 microg in 5 microl CSF was infused into the third ventricle (icv) with an automatic pump.

Sibutramine therapy in obese women--effects on plasma neuropeptide Y (NPY), insulin, leptin and beta-endorphin concentrations.

Objective: Some neuropeptides and monoaminergic neurotransmitters may affect hypothalamic feeding centres, sympathetic activity and thermogenesis. Sibutramine (BTS54524; N-[1-[1(4-chloro phenyl) cyclobutyl]-3methyl N,N-dimethylamine hydrochloride monohydrate) is a new 5-HT serotonin and noradrenaline reuptake inhibitor (SNRI), antiobesity drug. The aim of this study was to evaluate the effects of the sibutramine therapy on plasma neuropeptide Y (NPY), insulin, leptin and beta-endorphin concentrations in obese patients.

Effect of amylin on prolactin release.

Objective: Amylin is a 37-amino acid peptide that is secreted from the pancreatic beta cells. This peptide is cosecreted with insulin from the pancreas by glucose. Amylin plays a role in glucose homeostasis and in the regulation of lipid metabolism.