Disparate Effects of Stressors on Met-Enkephalin System Parameters and on Plasma Concentrations of Corticosterone in Young Female Chickens.

The effects of stressors were examined on Met-enkephalin-related parameters and plasma concentrations of corticosterone in 14-week-old female chickens. Water deprivation for 24 h was accompanied by a tendency for increased plasma concentration of Met-enkephalin while plasma concentrations of corticosterone were elevated in water-deprived birds. Concentrations of Met-enkephalin were reduced in the anterior pituitary gland and adrenal gland in water-deprived pullets while proenkephalin (PENK) expression was increased in both tissues.

Research Note: Morphine influences circulating and tissue concentrations of met-enkephalin and proenkephalin (PENK) expression and plasma concentrations of corticosterone in chickens.

The effects of the administration of the opioid agonist, morphine, on plasma and tissue concentrations of Met-enkephalin were determined in 14 wk old female chickens. In addition, effects of morphine on proenkephalin (PENK) expression were examined. Plasma concentrations of Met-enkephalin were reduced 10 minutes after morphine administration.

Effects of Restraint Stress on Circulating Corticosterone and Met Enkephalin in Chickens: Induction of Shifts in Insulin Secretion and Carbohydrate Metabolism.

This study examined the effects of acute restraint stress in the presence or absence of naltrexone on the circulating concentrations of insulin, glucose, Met-enkephalin and corticosterone in 14-week-old chickens [design: 2 sex × 2 stress/non-stress × 2 +/- naltrexone]. In chickens (five male and five females per treatment) subjected to restraint for 30 min, there were increases in the plasma concentrations of corticosterone and Met-enkephalin. The plasma concentrations of insulin and glucose were also increased in the chickens during restraint.

Avian opioid peptides: evolutionary considerations, functional roles and a challenge to address critical questions.

The present review considers the putative hormonal opioid peptides in birds. In birds and all other vertebrates, there are four opioid related genes encoding a series of peptides. These genes are, respectively, proenkephalin (PENK), prodynorphin (PDYN), pronociceptin (PNOC) and proopiomelanocortin (POMC).

Bilateral subdiaphragmatic vagotomy modulates the peripheral met‑enkephalin and striatal monoamine responses to peripheral inflammation in rat.

In the central nervous system, long‑term effects of a vagotomy include disturbance of monoaminergic activity of the limbic system. Since low vagal activity is observed in major depression and autism spectrum disorder, the study aimed to determine whether animals fully recovered after subdiaphragmatic vagotomy demonstrates neurochemical indicators of altered well‑being and social component of sickness behavior. Bilateral vagotomy or sham surgery was performed in adult rats.

Effect of selective cyclooxygenase inhibitors on animal behaviour and monoaminergic systems of the rat brain.

The long-term effects of cyclooxygenase 1 and 2 (COX-1/2) inhibitors are usually tested in terms of the periphery of the organism. Therefore, we studied the effects of SC560 (selective COX-1 inhibitor) and celecoxib (selective COX-2 inhibitor) on the activity of brain monoaminergic systems and animal behaviour. Additionally, we tested the effect of these inhibitors during inflammation.

Hypothalamic Neurochemical Changes in Long-Term Recovered Bilateral Subdiaphragmatic Vagotomized Rats.

Background: Vagus nerve is one of the crucial routes in communication between the immune and central nervous systems. The impaired vagal nerve function may intensify peripheral inflammatory processes. This effect subsides along with prolonged recovery after permanent nerve injury.

Opioid-like peptides and ghrelin mitigation of bariatric results depends on obesity level.

Introduction: Bariatric surgery, as the only effective treatment of obesity, has strong effects on the metabolism, and nervous and endocrine systems. Thus, based on the different opinions about the efficaciousness of morbid obesity treatments, the aim of the present study was to estimate the association of serum ghrelin and Met-enkephalin (native, five amino acids and cryptic, precursor of enkephalin) concentrations with body mass index (BMI) value in bariatric patients within 30 postoperative days.

Material And Methods: The study was performed on 38 female patients divided into two groups: I - BMI lower than 40 kg/m² (n = 18) and II - BMI higher than 40 kg/m² (n = 20).

Peripheral and central compensatory mechanisms for impaired vagus nerve function during peripheral immune activation.

Background: Determining the etiology and possible treatment strategies for numerous diseases requires a comprehensive understanding of compensatory mechanisms in physiological systems. The vagus nerve acts as a key interface between the brain and the peripheral internal organs. We set out to identify mechanisms compensating for a lack of neuronal communication between the immune and the central nervous system (CNS) during infection.

Isolation stress impacts Met-enkephalin in the hypothalamo-pituitary-adrenocortical axis in growing Polish Mountain sheep: a possible role of the opioids in modulation of HPA axis.

It was hypothesized that there is cross-talk between the classical constituents of the hypothalamo-pituitary-adrenocortical axis (HPA) and Met-enkephalin in the HPA axis. The study examined effects of isolation stress, sex, and age on concentrations of native Met-enkephalin and pro-enkephalin (PENK) gene expression in tissues of the HPA (hypothalamus, pituitary gland and adrenal cortex) in 3-, 6- and 9-month old female and male lambs. In addition, the effects of isolation stress on in vitro release Met-enkephalin from fragments of the hypothalamus or adrenal cortex were examined.

Perspectives on Endogenous Opioids in Birds.

The present review summarizes the state of knowledge of endogenous opioids in birds. Endogenous opioid peptides acts in a neuromodulatory, hormonal and paracrine manner to mediate analgesic and other physiological functions. These peptides act through specific G-protein coupled receptors.

Endocrine implications of obesity and bariatric surgery.

Introduction: Obesity is a highly prevalent disease in the world associated with the disorders of endocrine system. Recently, it may be concluded that the only effective treatment of obesity remains bariatric surgery. The aim of the review was to compare the concepts of appetite hormonal regulation, reasons of obesity development and bariatric procedures published over the last decade.

Hyperglycemia-induced changes in miRNA expression patterns in epicardial adipose tissue of piglets.

MicroRNAs (miRNAs) are a class of molecular posttranscriptional regulators found to participate in numerous biological mechanisms, such as adipogenesis, fat deposition, or glucose metabolism. Additionally, a detailed analysis on the molecular and cellular mechanisms of miRNA-related effects on metabolism leads to developing novel diagnostic markers and therapeutic approaches. To identify miRNA whose activity changed in epicardial adipose tissue in piglets during hyperglycemia, we analyzed the different miRNA expression patterns between control and hyperglycemia groups.

Adipose Tissue Tumor Necrosis Factor-α. and Interleukin-6 Response to Glucocorticoid Treatment during Inflammation.

The study was performed to examine the actions of glucocorticoids on cytokine (TNF-α and IL-6) concentrations in blood plasma, adipose tissue and cytokines gene expression during acute (streptozotocin, STZ treatment) and chronic inflammation (overweight) in Swiss mice. The experiment was carried out on 6-week-old animals divided into two groups: I - non-obese (fed with a commercial food) and II - overweight mice (fed with a high-fat diet). In each group mice were divided into 4 experimental subgroups: I - control, II - acute inflammation (STZ), III - treated with glucocorticoids (DEX), and IV - STZ with DEX.

The Effect of CRH, Dexamethasone and Naltrexone on the Mu, Delta and Kappa Opioid Receptor Agonist Binding in Lamb Hypothalamic-Pituitary-Adrenal Axis.

The aim of the study was to evaluate changes in the opioid receptor binding (mu, delta and kappa) in the hypothalamus, anterior pituitary and adrenal cortex (HPA) of lambs treated in vivo with corticotrophin releasing hormone (CRH), naltrexone, an opioid receptor antagonist (NAL), and dexamethasone, a potent cortisol analog (DEX). Experiment was carried out on 3 months old female lambs of polish mountain strain. Lambs received a single i.

mTOR Pathway - Novel Modulator of Astrocyte Activity.

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that belongs to the phosphoinositide-3-kinase-related family and has a crucial role in the integration of growth factors, energy factors and nutrient signaling. Abnormal activity of mTOR kinase can cause many neuropathologies, including brain tumours and neurodegenerative diseases. The study confirms that the use of a kinase inhibitor - rapamycin, allows to limit proliferation including inhibition of tumor cells and immune responses.

Met-enkephalins in patients with inflammatory bowel diseases.

Purpose: Opioid peptides provide a link between the neuroendocrine and immune systems. They modify the inflammatory process through their effect on the synthesis and secretion of cytokines and on the proliferation of leukocytes to the inflammatory lesion. The evaluation analyzed changes in free met-enkephalin concentration values in the serum and colon mucosal biopsy specimens of patients with inflammatory bowel disease (IBD).

Met-enkephalin in the liver as a marker of hepatocellular damage in chronic viral hepatitis type B and C.

Purpose: The aim of the study was to assess the liver Met-enkephalin concentration in chronic viral hepatitis type B and C as well as in liver cirrhosis in order to estimate the role of opioid system in pathogenesis of liver disease.

Material And Methods: The concentration of Met-enkephalin was examined in liver tissue of 103 consecutive patients with chronic hepatitis type B and C. Control group consisted of uninfected patients.

Effect of prolonged progesterone treatment on the proenkephalin mRNA gene expression and enkephalins concentration in the sheep brain.

The opioids modulate reproduction in sheep mostly by inhibiting the activity of the hypothalamo-pituitary-gonadal axis. However, the mechanism by which the negative feedback control systems regulate opioid synthesis and secretion in sheep is still not recognized. As a part of a research dealing with interaction between opioids and steroids, the effect of prolonged administration of progesterone (P4) and opioid receptor agonist or antagonist on the Met-enkephalin synthesis and concentration was examined in sheep brain.

Aspects of central and peripheral regulation of reproduction in mammals.

To increase our knowledge concerning the central and peripheral regulation of reproduction in mammals a series of studies were performed. In the first experiment, we found that exogenous leptin altered the activity of the hypothalmo-pituitary-gonadotropic axis in sheep during insufficient feeding. The action of leptin appears to be mediated by changes in GnRH and LH secretion as well as NPY immunoreactivity.

[Met-enkephalin in the cerebrospinal fluid as an indicator of central nervous system injury in meningitis and encephalitis].

The Aim: Assessment of met-enkephalin level in the cerebrospinal fluid (CSF) of patients with inflammatory process of the central nervous system (CNS) was performed to estimate the role of opioid system in viral and bacterial meningitis, and encephalitis.

Material And Method: The met-enkephalin level, protein concentration and pleocytosis were analysed in the CSF of 53 patients with viral or bacterial meningitis, encephalitis, and in the control group of patients without inflammatory disease of the CNS.

Results: The biggest differences have been observed between the groups of patients with bacterial meningitis and those without inflammatory disease of the CNS, but they were statistically insignificant.