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The impact of the mother on the hypothalamic-pituitary-adrenal, hypothalamic-pituitary-gonadal and somatotropic axes activity of offspring during postnatal ontogeny

100%

Chmielewska N., Wankowska M.

Zeszyty Naukowe. Acta Biologica. Uniwersytet Szczeciński

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2015

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tom 22

2

The pituitary endocrine mechanisms involved in mammalian maturation: maternal and photoperiodic influences

100%

Wankowska M., Polkowska J.

Reproductive Biology

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2010

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tom 10

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nr 1

3

Effect of maternal deprivation on the ganodotrophin-releasing hormone [GnRH] and GnRH-associated peptide neurobiology in lambs during the transition from infancy to prepuberty

100%

Wankowska M., Polkowska J.

Folia Histochemica et Cytobiologica

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2010

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tom 48

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nr 1

12-18

4

Stresogenny wplyw ostrego odseparowania od matki na wydzielanie hormonow ukladu podwzgorzowo-gonadotropowego jagniat

100%

Wankowska M., Polkowska J.

Działalność Naukowa PAN. Wybrane Zagadnienia

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2003

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tom 16

102-104

5

Effects of maternal deprivation on the somatotrophic axis and neuropeptide Y in the hypothalamus and pituitary in female lambs. The histomorphometric study

100%

Polkowska J., Wankowska M.

Folia Histochemica et Cytobiologica

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2010

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tom 48

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nr 2

299-305

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

81%

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.

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Central estrogen-like effect of genistein on growth hormone secretion in the ewe

81%

Misztal T., Wankowska M., Gorski K., Romanowicz K.

Acta Neurobiologiae Experimentalis

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2007

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tom 67

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nr 4

The present study tested a hypothesis, whether plant-derived genistein influences the secretion of growth hormone (GH) in ewes, acting directly within the central nervous system (CNS). Starting six weeks after ovariectomy, ewes were infused intracerebroventricularly with genistein (n=5) or 17β-estradiol (n=5), both in a total dose of 40 μg/400 μl/4 h, or with a vehicle (control, n=5). All infusions were performed from 10:00 am to 2:00 pm and blood samples were collected from 8:00 am to 8:00 pm at 10-min intervals. Five genistein- and three vehicle-infused ewes were slaughtered the following morning. The plasma GH concentration was assayed by the radioimmunoassay method, and immunoreactivity of GH in the adenohypophysis was determined by immunohistochemistry. In genistein-infused ewes, mean plasma GH concentration was significantly higher during the whole period of infusion than the concomitant concentration in vehicle-infused ewes. However, examining data within group, GH secretion rose gradually, reaching a significant value during the second phase of genistein infusion. In 17β-estradiol-infused animals, a significant increase in GH concentration was noted during the first two hours of the infusion, in comparison with vehicle-infused and also in comparison with genistein-infused ewes. Although a gradual increase in basic GH secretion continued in all treated groups during the afternoon and evening, mean plasma GH concentrations in genistein- and 17β-estradiol-infused ewes were still significantly higher than in the vehicle-infused. The percentage of GH-positive cells in the adenohypophysis and the density of immunoreactive material in these cells decreased significantly in genistein-infused ewes, compared to the control, indicating diminished hormone storage. In conclusion, genistein as 17β-estradiol, is an effective stimulator of GH secretion in ewes and may exert its effect at the level of the CNS.

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

80%

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

9

Sex-dependent differences in the effect of early weaning on the chosen hormones secretion in sheep during the postnatal transition to puberty – Preliminary results

71%

Cieslak, Chmielewska N., Romanowicz K., Mlynarczuk J., Wankowska M.

Polish Journal of Veterinary Sciences

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2015

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tom 18

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nr 1

The influence of early weaning on the cortisol, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and growth hormone (GH) secretion in lambs of both sexes and testosterone (T4) level in male lambs during the postnatal transition to puberty was investigated by radioimmunoassay. It was hypothesized that this influence is long-term and sexually dimorphic. Hence, the effect of weaning at 5 weeks of age in comparison with the weaning at 9 weeks of age on hormone concentrations in peripheral blood plasma of 5-, 9-, 12-, and 16-week-old lambs of both sexes was investigated. The cortisol concentrations were greater (P<0.05) in control and early weaned female lambs than in male lambs at investigated stages. Weaning at 5 weeks of age resulted in the lover (P<0.05) cortisol secretion in male lambs in contrast to the greater (P<0.05) cortisol secretion in female lambs at 16 weeks of age. Weaning at 5 weeks of age stimulated (P<0.001) the FSH secretion, but reduced (P<0.001) the LH, GH and T4 secretion in 16-week-old male lambs. In female lambs early weaning inhibited (P<0.05) the FSH secretion at 9 weeks of age, LH secretion after 9 weeks of age and GH secretion after 12 weeks of age. Thus, early weaning results in the sexually dimorphic stress reaction that is more potent and long-lasting in female in contrast to male lambs. This maternal deprivation stress contributes to the inhibition of LH and GH secretion in lambs of both sexes and T4 secretion in male lambs during the postnatal transition to puberty.

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

71%

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

71%

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

61%

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.

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

61%

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.

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Localization of kisspeptin neurons in the hypothalamus of peripubertal female lambs; possible connection with gonadotrophin releasing hormone and neuropeptide Y neurons

61%

Polkowska J., Picard S., Wankowska M., Cieslak M., Caraty A., Tillet Y.

Journal of Animal and Feed Sciences

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2014

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tom 23

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nr 2

Hypothalamic peptide kisspeptin (kp) plays a major role in the initiation of pubertal events in mammals through the activation of gonadotrophin- -releasing hormone (GnRH) neurons. The present study was designed to analyse the morpho-functional role of kisspeptin cells in the multimodal effects on GnRH secretion in female prepubertal lambs. The localization of kp immunoreactive (ir) expression was compared with that of GnRH release and neuropeptide Y (NPY) synthesis. The experiment was conducted on eight 32-week-old Merino lambs. The distribution of the peptides was estimated using immunohistochemistry and anti-kp, anti-GnRH and anti-NPY specific antibodies. The hypothalamic area containing numerous kp-ir perikarya and a dense network of kp-ir fibres was localized in the caudal part of the arcuate nucleus. Single axons and single perikarya were observed throughout the hypothalamus extending from the preoptic area to the mammillary bodies. Distinct bundles of kp-ir nerve terminals were observed in the lateral zone of the median eminence (ME) and dispersed in smaller quantities in its medial zone. Double immunostaining indicated that a third of the kp-ir neurons were in close apposition with NPY-ir afferents, and that the distribution of kp-ir nerve terminals in the ME matched that of GnRH-ir nerve terminals. To conclude, the presence of very large numbers of kp-ir neurons in the peripubertal period could be attributed to their stimulating action on the GnRH neuronal system during this period. This influence could act directly in the ME, where both peptides are released. In addition, kp-ir neurons could mediate the effect of NPY on GnRH secretion.

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Aspects of central and peripheral regulation of reproduction in mammals

42%

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

The impact of the mother on the hypothalamic-pituitary-adrenal, hypothalamic-pituitary-gonadal and somatotropic axes activity of offspring during postnatal ontogeny

The pituitary endocrine mechanisms involved in mammalian maturation: maternal and photoperiodic influences

Effect of maternal deprivation on the ganodotrophin-releasing hormone [GnRH] and GnRH-associated peptide neurobiology in lambs during the transition from infancy to prepuberty

Stresogenny wplyw ostrego odseparowania od matki na wydzielanie hormonow ukladu podwzgorzowo-gonadotropowego jagniat

Effects of maternal deprivation on the somatotrophic axis and neuropeptide Y in the hypothalamus and pituitary in female lambs. The histomorphometric study

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

Central estrogen-like effect of genistein on growth hormone secretion in the ewe

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

Sex-dependent differences in the effect of early weaning on the chosen hormones secretion in sheep during the postnatal transition to puberty – Preliminary results

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

Localization of kisspeptin neurons in the hypothalamus of peripubertal female lambs; possible connection with gonadotrophin releasing hormone and neuropeptide Y neurons

Aspects of central and peripheral regulation of reproduction in mammals