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1

Morphological and physiological base of appetite regulation in the hypothalamus. A review

100%

Wojcik-Gladysz A.

Journal of Animal and Feed Sciences

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2004

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tom 13

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nr 2

239-255

2

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Neuromodulatory action of obestatin on the secretory activity of the hypothalamic - pituitary axis

63%

Szlis M., Wojcik-Gladysz A.

Zeszyty Naukowe. Acta Biologica. Uniwersytet Szczeciński

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2014

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tom 21

3

Hypothalamo-gastrointestinal axis – role in food intake regulation

63%

Wojcik-Gladysz A., Szlis M.

Journal of Animal and Feed Sciences

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2016

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tom 25

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nr 2

In homoeothermic vertebrates, one of the most important physiological mechanism concerns the maintenance of the homeostasis. The principal regulator of energy intake is situated in the central nervous system (CNS), where numerous central and peripheral hormones regulate the energy homeostasis. Neuronal pathways between some hypothalamic nuclei create the appetite regulating network in which orexigenic and anorexigenic circuits modify food intake and energy expenditure. In recent years, a serious problem concerning obesity and related diseases emerged in civilized societies. In order to resolve the issues of disturbances of food intake, it is necessary to understand mechanisms guiding neuroendocrine control of metabolic processes. Previous studies have focused on the role of gut peptides (now called gastrointestinal hormones) only in the regulation of the gastrointestinal tract function. Nowadays, it has become clear that gut hormones signalize neural and endocrine mechanisms to the CNS to create the brain-gut axis which regulates energy homeostasis. This review is an attempt to summarize the knowledge about the hypothalamus-gastrointestinal axis. In the first part of the review the hypothalamic ‘centre’, engaged in the body energy homeostasis regulation and being the most important neuropeptide acting in this region, is presented. In the second one, the information about the origin, properties and some endocrine actions of the most important and best studied, in our opinion, gastrointestinal hormones regulating the food intake is reviewed. Detailed knowledge of the regulation of appetite mechanisms should be an opportunity to overcome an increasingly common problem of civilization – the epidemic of obesity

4

Neuropeptide Y - a neuromodulatory link between nutrition and reproduction at the central nervous system level

63%

Wojcik-Gladysz A., Polkowska J.

Reproductive Biology

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2006

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tom 06

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nr Suppl.2

5

Brain-derived neurotrophic factor affects mRNA and miRNA expression of the appetite regulating centre in the sheep arcuate nucleus

51%

Przybyl B. J., Szlis M., Wojcik-Gladysz A.

Annals of Animal Science

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2020

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tom 20

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nr 3

6

Wplyw niedoborowego zywienia owiec na regulacje hormonalne zwiazane ze wzrostem i rozrodem; posredniczaca rola neuropeptydu Y

51%

Palkowska J., Wojcik-Gladysz A., Wankowska M.

Postępy Nauk Rolniczych

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2004

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tom 51

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nr 4

3-15

The relationship between nutrition level and processes of growth and reproduction in animals are generally regulated by two endocrine systems: hypothalamo-pituitary somatotrophic and/or gonadotrophic axes. Diets deficient in energy and protein, elicit disturbances in the growth hormone secretion both in growing and mature sheep. Paradoxical enhancing the concentration of this hormone and parameters of its pulsatile release are due to suppression of the hypothalamic somatostatin and result in diminishing of the daily body gains and final body weight. The energetic and protein restrictions in sheep nutrition elicit also the disturbances in hypothalamo-pituitary-gonadotrophic axis in adult and growing sheep. The LH synthesis in pituitary cells and its pulsatile release to circulating blood are being reduced due to lowering of the parameters of pulsatile GnRH release of from the hypothalamus. In physiological response, the suppression of processes leading to the puberty in lambs and disturbances in course of the oestrus cycle in mature sheep, are observed. The study performed on sheep confirm the hypothesis that the neuropeptide Y could be a neuromodulatory link between animal nutrition and growth. However, the role of neuropeptide Y as a neuromodulatory interface between nutrition and reproduction needs the further elucidation.

7

Oestrogen-like effect of genistein on follicle - stimulating hormone release in ovariectomized ewes

51%

Wojcik-Gladysz A., Romanowicz K., Misztal T., Polkowska J.

Journal of Animal and Feed Sciences

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2006

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tom 15

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nr 4

579-589

Phytoestrogens, plant-derived oestrogen-like compounds exert numerous effects on the reproductive functions of animals. The present study was designed to demonstrate if exogenous genistein infused during the breeding season into the third ventricle of the brain of ovariectomized (OVX) ewes could affect the follicle stimulating hormone (FSH) release from the pituitary cells. Two year old OVX ewes (n=8) were infused with vehicle (control, n=3) or genistein (10 μg/100 μl/h, n=5) into the third ventricle. The infusions were done from 10.00 to 14.00 h and blood samples collection was performed this day from 8.00 up to 20.00 h and next day from 8.00 to 10.00 h. The animals were slaughtered thereafter. FSH cells in the adenohypophysis were localized by immunohistochemistry. Plasma FSH concentrations were measured by radioimmunoassay. Immunohistochemical analysis revealed that the number of immunoreactive (IR) FSH cells in the adenohypophysis and IR material stored in these cells increased in genistein-infused animals, microscopic observations were confirmed by statistical analysis (P<0.001). The concentrations of FSH was significantly lower 20 h after genistein infusions, as compared to the values noted in vehicle infused ewes (34.18±1.36 vs 40.62±2.69; P<0,05), respectively. The presented results demonstrated that genistein could affect the FSH release in the OVX ewes.

8

Differences in the secretion pattern of growth hormone and insulin-like growth factor-I in sheep of two crossbreeds after dietary protein restriction

51%

Wojcik-Gladysz A., Krejci P., Polkowska J.

Journal of Animal and Feed Sciences

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2002

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tom 11

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nr 4

9

Expression of NPY-immunoreactive neurons in the hypothalamus of the cycling ewe

51%

Polkowska J., Wankowska M., Wojcik-Gladysz A.

Folia Histochemica et Cytobiologica

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2006

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tom 44

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nr 1

10

Does prolactin influence the hypothalamo-pituitary GnRH-LH system in preovulatory-phase ewes?

45%

Misztal T., Romanowicz K., Wankowska M., Wojcik-Gladysz A., Polkowska J.

Reproductive Biology

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2005

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tom 05

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nr 1

11

Effect of central infusions of neuropeptide Y on GnRH/LH axis in ewes during the early anoestrous period

45%

Wojcik-Gladysz A., Misztal T., Wankowska M., Romanowicz K., Polkowska J.

Reproductive Biology

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2003

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tom 03

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nr 1

12

The effect of intracerebroventricular infusions of ghrelin on the secretory activity of the GnRH/LH system in peripubertal ewes

39%

Wojcik-Gladysz A., Wankowska M., Gajewska A., Misztal T., Szlis M., Polkowska J.

Journal of Animal and Feed Sciences

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2014

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tom 23

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nr 4

Ghrelin is a 28-amino acid orexigenic peptide, synthesized mainly by cells located in the stomach mucosa, that can be also engaged in modulation of reproductive functions. The aim of this study was to investigate the effect of intracerebroventricular (icv) infusion of ghrelin on the secretory activity of the gonadotropin hormone releasing hormone/luteinizing hormone (GnRH/ LH) system in peripubertal ewes. The animals were randomly divided into three groups: 1. standard fed, 2. starved for 72 h, and 3. standard fed + icv infused with ghrelin. Infusions were performed during three consecutive days; blood samples were collected on day 0 and day 3. Ghrelin infusions and short-term starvation increased the accumulation of immunoreactive (ir) GnRH material in the median eminence (P < 0.001) and ir LH material in the secretory granules of pituitary cells (P < 0.001) in the fasted and ghrelin-infused groups. The short starvation resulted in a decrease of mean LH plasma concentrations (P < 0.05) between days 0 and 3 of infusion, which was related to a lower pulse amplitude. After the icv ghrelin infusion, significant (P < 0.05) changes in LH pulse amplitude and frequency, but not in LH concentrations were observed. The obtained results revealed that in peripubertal ewes, exogenous ghrelin administration affects the GnRH/LH axis mainly at the level of neurohormone/protein accumulation and LH pulsatility modifications. Ghrelin action at the hypothalamuspituitary axis is likely involved in the endocrine network that integrates energy balance and fertility in immature sheep.

13

The effect of intracerebroventricular infusion of leptin on the secretory activity of the somatotrophic axis in fasted prepubertal lambs

39%

Wojcik-Gladysz A., Wankowska M., Misztal T., Szczepankiewicz D., Romanowicz K., Polkowska J.

Journal of Animal and Feed Sciences

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2010

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tom 19

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nr 3

The aim of the present study was to investigate the effect of exogenous leptin on somatotrophic axis regulation in prepubertal female lambs under conditions of acute undernutrition (72 h fasting). The analyses in fasted sheep revealed enhancement of immunoreactive (ir) somatostatin stores in perikarya of the periventricular (PEV) nucleus and in terminals of the median eminence (ME) (P<0.001), enhancement of growth hormone (GH) mRNA expression in the adenohypophysis, diminishing of ir GH stores in somatotrophs in the adenohypophysis (P<0.001), and a rise in GH pulsatility (P<0.05) in the blood in comparison with standard-fed sheep. In fasted sheep infused with leptin, additional enhancement of ir somatostatin stores in the PEV nucleus and in the ME (P<0.001), an increase in GH mRNA expression in the adenohypophysis (P<0.001), and augmentation of GH pulsatility (P<0.05) in the blood plasma were noted. In conclusion, acute undernutrition affects somatotrophic axis by enhancement of GH secretion via restraining of somatostatin output. Exogenous leptin additionally amplifies this effect by suppressing somatostatin release and increasing of GH secretion. The results provide evidence that leptin can regulate somatotrophic axis activity in prepubertal female lambs under conditions of acute fasting.

14

Aspects of central and peripheral regulation of reproduction in mammals

27%

Wojcik-Gladysz A., Nowak K. W., Pierzchala-Koziec K., Wankowska M., Misztal T., Polkowska J., Nowak M., Kaczmarek P., Gorska T., Szczepankiewicz D., Zubel J.

Reproductive Biology

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2006

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tom 06

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nr Suppl.1

Ograniczanie wyników

Morphological and physiological base of appetite regulation in the hypothalamus. A review

Neuromodulatory action of obestatin on the secretory activity of the hypothalamic - pituitary axis

Hypothalamo-gastrointestinal axis – role in food intake regulation

Neuropeptide Y - a neuromodulatory link between nutrition and reproduction at the central nervous system level

Brain-derived neurotrophic factor affects mRNA and miRNA expression of the appetite regulating centre in the sheep arcuate nucleus

Wplyw niedoborowego zywienia owiec na regulacje hormonalne zwiazane ze wzrostem i rozrodem; posredniczaca rola neuropeptydu Y

Oestrogen-like effect of genistein on follicle - stimulating hormone release in ovariectomized ewes

Differences in the secretion pattern of growth hormone and insulin-like growth factor-I in sheep of two crossbreeds after dietary protein restriction

Expression of NPY-immunoreactive neurons in the hypothalamus of the cycling ewe

Does prolactin influence the hypothalamo-pituitary GnRH-LH system in preovulatory-phase ewes?

Effect of central infusions of neuropeptide Y on GnRH/LH axis in ewes during the early anoestrous period

The effect of intracerebroventricular infusions of ghrelin on the secretory activity of the GnRH/LH system in peripubertal ewes

The effect of intracerebroventricular infusion of leptin on the secretory activity of the somatotrophic axis in fasted prepubertal lambs

Aspects of central and peripheral regulation of reproduction in mammals