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Neuralna regulacja uwalniania gonadoliberyny /GnRH/ - rola receptorow GABA w podwzgorzu i okolicy przedwzrokowej u owcy.

100%

Tomaszewska-Zaremba D., Przekop F.

Działalność Naukowa PAN. Wybrane Zagadnienia

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2002

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tom 14

113-115

2

The role of GABAA and GABAB receptors in the control of GnRH release in anestrous ewes

100%

Tomaszewska-Zaremba D., Przekop F.

Reproductive Biology

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2006

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tom 06

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nr Suppl.2

3

Immune stress up regulates TLR4 and Tollip gene expression in the hypothalamus of ewes

81%

Herman A. P., Herman A., Haziak K., Tomaszewska-Zaremba D.

Journal of Animal and Feed Sciences

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2013

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tom 22

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nr 1

Bacterial endotoxin, LPS, is recognized by Toll-like receptor-4 (TLR4) and induces a signaling cascade leading to synthesis of proinflammatory cytokines and induction of sickness behavior in animals. Transduction of the TLR4 signal is controlled by a potent negative regulator—Toll-interacting protein. The presented study concerns the effect of intravenously injected LPS on the level of expression of TLR4 and Tollip genes in the hypothalamus of ewes. Endotoxin increased (P < 0.01) cortisol release and expression of TLR4 and Tollip genes in the preoptic area (1.87 ± 0.42 and 1.31 ± 0.15), anterior hypothalamus (1.77 ± 0.22 and 1.27 ± 0.13), medial basal hypothalamus (2.53 0.65 and 1.43 ± 0.15), and median eminence (2.93 ± 0.46 and 1.73 ± 0.10), respectively, in comparison with non-treated animals. Our results show that immune stress increases TLR4 gene expression in the hypothalamus. Increased transcription of Tollip may be an attempt to reduce the effect of TLR4 stimulation.

4

The effect of LPS on LH release and gene expression of LH-beta, GnRH-R and TLR4 in the anterior pituitary of follicular phase ewes - an in vitro study

81%

Haziak K., Herman A. P., Tomaszewska-Zaremba D.

Journal of Animal and Feed Sciences

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2013

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tom 22

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nr 2

The study was designed to determine the in vitro effect of bacterial endotoxin – lipopolysaccharide (LPS) – on luteinizing hormone (LH) secretion from anterior pituitary (AP) explants collected from saline-treated ‘healthy’ and LPS-treated ewes in the follicular phase. In the AP explants, the expression of LH-β, gonadotropin-releasing hormone receptor (GnRH-R) and Toll-like receptor 4 (TLR4) genes was also assayed. It was found that explants incubated alone with LPS, as well as together with LPS-binding protein (LBP), abolished the stimulatory effect of GnRH on LH release. LPS added without LBP did not suppress LH-β gene expression in ‘healthy’ APs, however. Moreover, LBP intensified the inhibitory effect of LPS on gene expression in ‘healthy’ APs. These results show that LPS is a potent negative modulator of LH secretion and suggest that its direct action on the pituitary gland could be one of the mechanisms via which an immune/inflammatory challenge inhibits the reproductive process.

5

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Neuralna regulacja uwalniania gonadoliberyny u owcy w roznych stanach fizjologicznych; rola receptorow GABA-A

81%

Tomaszewska-Zaremba D., Mateusiak K., Przekop F.

Postępy Nauk Rolniczych

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2005

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tom 52

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nr 5

7-16

One of the most important inhibitory neurotransmitter in the control of gonadoliberin (GnRH) secretion is gamma-aminobutyric acid (GABA). To examine the role of GABAA receptor mediating systems in the control of GnRH/LH release from the preoptic area and ventromedial hypothalamus of ewes in different reproductive stages (seasonal anestrus, follicular and luteal phase of the estrous cycle) the extracellular concentration of GnRH, ß-endorphin, noradrenaline, dopamine and metabolites of catecholamines: MHPG, DOPAC were quantified during local stimulation or blockade of GABAA receptors with muscimol or bicuculline, respectively. Stimulation of GABAA receptors in the preoptic area and ventromedial hypothalamus markedly attenuatted GnRH/LH release in the anestrous ewes and in sheep during follicular phase of the estrous cycle but did not affect these hormones secretion in animals during the luteal phase of the estrous cycle. The activation of GABAA receptors in these structures in different way affected ß-endorphinergic and catecholaininergic system activity in anestrous ewes arid animals during the follicular phase; lack of changes in the release of ß-endorphin, noradrenaline and dopamine was noted in ewes during the luteal phase. With the exception of preoptic area in anestrous ewes the blockade of GABAA receptors in the preoptic and ventromedial hypothalamus affected in specifical way the activity of ß-endorphinergic and catecholaminergic systems in these structure in all animals. In conclusion: presented results indicate that activation of GABAA receptors in the preoptic area and ventromedial hypothalamus of anestrous ewes and sheep during follicular phase of the estrous cycle inhibits GnRH/LH secretion. Presented results indicate that different neural mechanisms may be involved in the suppression of GnRH/LH by GABA directly through the GABAA receptor mechanism on the perikaria or on the axon terminals of GnRH cells, and/or indirectly through GABAA receptor processes on ß-endorphinergic and catecholaminergic systems. Lack of changes in GnRH/LH release during GABAA receptor activation in ewes during luteal phase of the estrous cycle indicates that the influence of GABA on GnRH-ergic activity depends on physiological state of animals. Blockade of GABAA receptors in the anestrous and cycling ewes does not change GnRH/LH release; it is suggested that blockade of GABAA recreceptors may change GnRH neurons response to ß-endorphin and dopamine.

6

Does central IL-1beta affect GnRH secretion in the hypothalamus of anoestrous ewes via different regulatory pathways?

81%

Tomaszewska-Zaremba D., Herman A. P., Misztal T.

Journal of Animal and Feed Sciences

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2013

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tom 22

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nr 1

The study was designed to identify the central pathways through which central interleukin-1β (IL-1β) affects gonadotropin-releasing hormone (GnRH) release in anoestrous ewes. Our results show that intracerebroventricular (icv.) injection of IL-1β (50 µg) decreases the GnRH concentration in the perfusates collected from the medial basal hypothalamus/median eminence (MBH/ME), increases its type I receptor gene expression in the preoptic area, anterior hypothalamus (AHA) and medial basal hypothalamus, and significantly decreases the neuropeptide Y (NPY) mRNA level in the AHA and MBH. No effect of IL-1β treatment was found on plasma cortisol concentration, catecholamine (norepinephrine and dopamine) levels in perfusates, as well as cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) gene expression in the hypothalamus. Our data demonstrate that central IL-1β suppresses GnRH release mainly by acting directly through its own hypothalamic receptors, and its effect could be, at least partially, caused by changes in the NPY level, which is known as an important modulator of GnRH biosynthesis and release.

7

How does bacterial endotoxin influence gonadoliberin/gonadotropins secretion and action?

81%

Tomaszewska-Zaremba D., Herman A. P., Haziak K.

Journal of Animal and Feed Sciences

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2016

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tom 25

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nr 4

This review summarizes data concerning the mechanisms by which bacterial endotoxin, lipopolysaccharide (LPS), inhibits gonadoliberin (GnRH)/ luteinizing hormone (LH) secretion in mammals. LPS is a major component of Gram-negative bacteria cell walls and is released from the surface of replicated and dying Gram-negative bacteria into circulation. LPS is commonly used to induce immune/inflammatory challenge in animals. In this article the site of endotoxin action as well as LPS induced mediators are discussed. Hypothalamus seems to be a place where majority of the immune-neuroendocrine interactions occur, however the results of many research suggest that LPS may interfere with reproductive system at the pituitary level as well. Endotoxin may affect GnRH/LH secretion directly via toll-like receptors (TLR)4/TLR2 located both in the hypothalamus and pituitary or indirectly through the intermediates such as cytokines, catecholamines, prostaglandins or opioids.

8

Photoperiod-dependent effect of inflammation on nocturnal gene expression of proinflammatory cytokines and their receptors in pars tuberalis of ewe

81%

Krol K., Tomaszewska-Zaremba D., Herman A. P.

Journal of Animal and Feed Sciences

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2016

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tom 25

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nr 1

The study was designed to determine the influence of photoperiod on the nocturnal gene expression of proinflammatory cytokines such as interleukin (IL)-1β (IL1B), IL-6 (IL6), tumor necrosis factor α (TNF) and their receptors: IL-1 type I receptor (IL1R1), IL-6 receptor (IL6R), glycoprotein 130 (IL6ST), TNF type I and II receptors (TNFRSF1A and TNFRSF1B, respectively) in the pars tuberalis (PT) of ewe with the endotoxin-induced acute inflammation. The studies were performed on adult ewe (n = 24) in two photoperiods: long night (LN; 16:8; October) and short night (SN; 8:16; June). The animals from each photoperiod were divided into two groups: control (n=6) and lipopolysaccharide (LPS)-treated (n = 6). All experiment steps were performed in the darkness. Two hours after the sunset the ewe received the intravenous injection of LPS or an appropriate volume of saline. Three hours after the injections all animals were slaughtered. It was found that melatonin concentration in control ovine serum was higher (P< 0.05) during LN than SN period. Endotoxin decreased (P < 0.05) the melatonin release only in ewe kept under SN condition. The transcripts encoding all examined proinflammatory cytokines and their receptors were expressed in the PT. Moreover, the PT collected from LPS-treated ewe during LN were characterized with higher (P < 0.05) expression of IL6, TNF, IL6ST, TNFRSF1A and TNFRSF1B genes compared with the tissues collected during SN. Similar influence of photoperiod was also observed in the case of TNF gene expression in the control sheep. Obtained results suggest that the PT may be one of the gateways for immune-endocrine interactions and these interactions may be affected by the photoperiod.

9

The role of GABAa receptors in the neural systems of the medial preoptic area in the control of GnRH release during the luteal phase of the oestrous cycle in ewes

80%

Tomaszewska-Zaremba D., Mateusiak K., Przekop F.

Journal of Animal and Feed Sciences

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2004

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tom 13

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nr 1

10

The involvement of GABA A receptors in the control of GnRH and beta-endorphin release, and catecholaminergic activity in the ventromedial-infundibular region of hypothalamus in anestrous ewes

80%

Tomaszewska-Zaremba D., Przekop F., Mateusiak K.

Journal of Physiology and Pharmacology

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2001

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tom 52

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nr 3

11

The role of GABAA receptors in the neural systems of the ventromedial-infundibular region of the hypothalamus in the control of gonadotropin release during the luteal phase in ewes

80%

Tomaszewska-Zaremba D., Mateusiak K., Przekop F.

Journal of Physiology and Pharmacology

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2002

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tom 53

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nr 4,2

To examine the role of GABAA receptor mediating systems in the control of gonadotropin-releasing hormone (GnRH) release from the ventromedial- infundibular region (VEN/NI) in ewes during luteal phase, the extracellular concentrations of GnRH, ß-endorphin, noradrenaline (NE), dopamine (DA), and their metabolites: MHPG and DOPAC were quantified by local stimulation or blockade of GABAA receptors with muscimol or bicuculline, respectively. Stimulation of GABAA receptors in the VEN/NI did not affect GnRH, ß-endorphin release or catecholaminergic system activity. Blockade of GABAA receptors decreased ß-endorphinergic and dopaminergic activity, and lowered the extracellular concentration of MHPG. It did not affect GnRH release or luteinizing hormone (LH) secretion. It is suggested that progesterone-induced GABAergic activity during the luteal phase may desensitize GABAA receptors to muscimol. Lack of changes in GnRH/LH secretion with concomitant depressed ß-endorphinergic activity corroborated the conclusion that ß-endorphin does not inhibit GnRH release from the VEN/NI during the luteal phase. The physiological significance of changes in the catecholaminergic system activity under GABAA receptor blockade in the control of GnRH secretion awaits to be established.

12

Wpływ dodatku preparatu zakwaszającego do paszy na wykorzystanie tryptofanu przez młode świnie

71%

Swiech E., Pastuszewska B., Tomaszewska-Zaremba D., Buraczewska L., Taciak M.

Prace i Materiały Zootechniczne. Zeszyt Specjalny

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2004

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nr 15

13

The effect of repeated endotoxin injection on gonadotropin secretion in ewes

71%

Herman A. P., Kopycinska K., Krawczynska A., Romanowicz K., Tomaszewska-Zaremba D.

Journal of Animal and Feed Sciences

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2014

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tom 23

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nr 3

Although it is well known that acute inflammation induced by a single injection of the bacterial endotoxin, lipopolysaccharide (LPS), induces a stress response and suppresses luteinizing hormone (LH) secretion, the effects of repeated endotoxin administration on gonadotropin secretion in sheep have not been studied yet. In this work, the influence of inflammation induced by six days of intravenous LPS injection (400 ng· kg–1 per day) on the release of LH and follicle-stimulating (FSH) hormones was evaluated. Anoestrous ewes were bled twice a day 1 h before and 3 h after LPS injection. Endotoxin injection decreased (P < 0.05) the release of LH from the first day of the experiment. Moreover, on day 5, the suppression of LH secretion was sustained and could also be detected in the samples collected before the next LPS injection. In contrast, elevation (P < 0.05) of FSH release was detected starting from the second dose of the endotoxin. The increased FSH concentration persisted until the end of the experiment. Each LPS injection stimulated (P < 0.05) cortisol release, but from days 3 to 6, this elevation was about three times lower than the level determined during the first two days. The obtained results show that ewes exposed to repeated administration of endotoxin lost their ability to restore proper LH release relatively quickly. This disturbance in gonadotropin secretion could, in part, be associated with the stress induced by LPS, as well as with endotoxin-induced inflammatory challenges.

14

The influence of salsolinol on dopaminergic system activity within the mediobasal hypothalamus of anestrous sheep: A model for studies on the salsolinol-dopamine relationship

61%

Misztal T., Hasiec M., Tomaszewska-Zaremba D., Dobek E., Fulop F., Romanowicz K.

Acta Neurobiologiae Experimentalis

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2011

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tom 71

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nr 3

Salsolinol with its derivatives has been considered as a potential neurotoxin for the dopaminergic system in the human and rat brain. Investigating a sheep model for studies on the action of salsolinol within the central nervous system we examined whether this compound is able to affect the hypothalamic neuroendocrine dopaminergic (NEDA) system during its high seasonal activity, when sheep entered to anestrus under the long day conditions. Therefore, salsolinol was infused into the third ventricle of the brain in combination with the in vivo push-pull perfusion of the mediobasal hypothalamus/median eminence (MBH/ME). The effects of this drug on either perfusate noradrenaline (NA) or plasma prolactin concentration were also studied. The infusion of salsolinol resulted in rapid and permanent diminution in dopamine (DA) release into the extracellular spaces of the MBH/ME up to an undetectable level and in the 57% decrease in DA metabolite 3,4- dihydroxyphenylacetic acid concentration, compared to the control. This effect of salsolinol was accompanied by the significant enhancement of the pituitary prolactin release into circulation. The concentration of other DA metabolite, homovanillic acid, as well as NA in the MBH/ME was not affected. Thus, our results in the anestrous sheep underline the role played by salsolinol as a neuromodulator for the hypothalamic NEDA system and as a signal transmitter for the pituitary prolactin release. We suggest that the hypothalamic NEDA system of anestrous sheep during its high secretory activity may be set as a model for studies on the salsolinol-dopamine relationship.

15

Caffeine stimulates in vitro pituitary LH secretion in lipopolysaccharide-treated ewes

61%

Herman A. P., Herman A., Skipor J., Krawczynska A., Bochenek J., Tomaszewska-Zaremba D.

Reproductive Biology

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2015

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tom 15

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nr 1

16

Effects of acidifier added to diets containing graded levels of crystalline tryptophan on growth performance, protein digestibility, and on brain serotonin level in broiler chickens

61%

Smulikowska S., Pastuszewska B., Tomaszewska-Zaremba D., Buraczewska L., Nguyen C. V., Mieczkowska A.

Journal of Animal and Feed Sciences

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2004

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tom 13

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nr 2

289-300

Ograniczanie wyników

Neuralna regulacja uwalniania gonadoliberyny /GnRH/ - rola receptorow GABA w podwzgorzu i okolicy przedwzrokowej u owcy.

The role of GABAA and GABAB receptors in the control of GnRH release in anestrous ewes

Immune stress up regulates TLR4 and Tollip gene expression in the hypothalamus of ewes

The effect of LPS on LH release and gene expression of LH-beta, GnRH-R and TLR4 in the anterior pituitary of follicular phase ewes - an in vitro study

Neuralna regulacja uwalniania gonadoliberyny u owcy w roznych stanach fizjologicznych; rola receptorow GABA-A

Does central IL-1beta affect GnRH secretion in the hypothalamus of anoestrous ewes via different regulatory pathways?

How does bacterial endotoxin influence gonadoliberin/gonadotropins secretion and action?

Photoperiod-dependent effect of inflammation on nocturnal gene expression of proinflammatory cytokines and their receptors in pars tuberalis of ewe

The role of GABAa receptors in the neural systems of the medial preoptic area in the control of GnRH release during the luteal phase of the oestrous cycle in ewes

The involvement of GABA A receptors in the control of GnRH and beta-endorphin release, and catecholaminergic activity in the ventromedial-infundibular region of hypothalamus in anestrous ewes

The role of GABAA receptors in the neural systems of the ventromedial-infundibular region of the hypothalamus in the control of gonadotropin release during the luteal phase in ewes

Wpływ dodatku preparatu zakwaszającego do paszy na wykorzystanie tryptofanu przez młode świnie

The effect of repeated endotoxin injection on gonadotropin secretion in ewes

The influence of salsolinol on dopaminergic system activity within the mediobasal hypothalamus of anestrous sheep: A model for studies on the salsolinol-dopamine relationship

Caffeine stimulates in vitro pituitary LH secretion in lipopolysaccharide-treated ewes

Effects of acidifier added to diets containing graded levels of crystalline tryptophan on growth performance, protein digestibility, and on brain serotonin level in broiler chickens