Wyniki wyszukiwania

1

Changes of progesterone level is the plasma of sows during the estrous cycle

100%

Okrasa S.

Acta Physiologica Polonica

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1978

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tom 29

|

nr 2

2

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Poziom ACTH i kortykoidów w cyklu płciowym u loszek

63%

Okrasa S., Tilton J. E.

Zeszyty Problemowe Postępów Nauk Rolniczych

|

1984

|

tom 309

3

Postęp w badaniach dotyczących procesów rozrodczych u świń

63%

Okrasa S., Strzezek J.

Postępy Nauk Rolniczych

|

2007

|

tom 59

|

nr 3

4

Oxytocin plasma level in the lactating sows - effect of suckling

63%

Kotwica G., Okrasa S.

Acta Physiologica Polonica

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1989

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tom 40

|

nr 1

Kotwica, G. and Okrasa, S.: Oxytocin plasma level in the lactating sows- effect of suckling. Acta physiol, poil., 1989, 40 (1): 104-110. Oxytocin concentration in the peripheral Iblood was measured toy RIA during suckling period in lactating sows (n = 8). Blood samples were ta'ken from the jugular vein around the clock for every 2 h on day 5, 10, 15, 20, 25, 30 and on day 35 of lactation. Besides that blood samples were collected more frequently during suckling periods. Oxytocin plasma concentration wias very low and in most cases it was on a border of sensitivity of our method (3pg/ml). Marked but short-lasting rise of oxytocin was observed only during a period of initial massage of the udders by the piglets. This rise observed in all studied pigs was higher (p < 0.01) compared to the values before the massage on the onset of lactation only, and was 14.6'± ±4.2 pg/ml and 6.4±1.2 pg/ml on day 5 and day 10 of lactation, respectively. to all other studied days in a few cases only suckling stimulated the release of oxytocin over its basic concentration. Mean values (±SEM) of oxytocin in hlood samples collected during massage of udder on day 15. 20, 25, 30 and day 35 were 3.7+0.5, 4.2±0.8, 4.9±1.1, 3.2 ±0,4 and 3.0 ± ±0.6 pg/ml plasma, respectively. There was no relationship between the size of the litters and neither basic level of oxytocin nor its blood concentration during suckling (r = 0.13).

5

Opioid antagonist and agonist effects on GnRH release in vitro from the SME of ovariectomized gilts primed with steroids

63%

Okrasa S., Kalamarz H.

Folia Histochemica et Cytobiologica. Supplement

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1997

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tom 35

|

nr 2

6

The expression of genes coding for opioid precursors, opioids receptors, beta-LH subunit and GnRH receptor in the anterior pituitary of cyclic gilts

51%

Wylot B., Staszkiewicz J., Okrasa S.

Journal of Physiology and Pharmacology

|

2008

|

tom 59

|

nr 4

745-758

In previous studies the effect of endogenous opioid peptides (EOP) on LH secretion was mainly considered at the hypothalamic level, while opioid involvement in the modulation of LH secretion at the pituitary level remains insufficiently elucidated. Therefore, the present study was undertaken to determine the expression of genes encoding opioid precursors – proopiomelanocortin (POMC), proenkephalin (PENK), prodynorphin (PDYN) and opioid receptors – mu, delta, kappa in the porcine anterior pituitary throughout the estrous cycle. Additionally, the mRNA content of ß-LH subunit and GnRH receptor (GnRH-R) was estimated. Pituitaries (5×N = 7) were collected from sows on days 3-5, 8-10, 13-15, 16-17 and 19-20 of the cycle and gene expression was determined using a semi-quantitative RT-PCR assay. The expression of POMC, PDYN, delta and kappa receptor genes was variable across the cycle, whereas the expression of PENK and mu receptor genes remained relatively stable. The POMC mRNA content was the lowest on days 19-20 of the cycle and the PDYN content was reduced on days 8-10. The delta receptor mRNA content was elevated on days 3-5, while the kappa receptor mRNA content was decreasing over the luteal phase. Changes in the expression of genes encoding ß-LH and GnRH-R were also demonstrated. These results indicate variable activity of pituitary opioid systems in cyclic pigs and suggest implication of EOP in the modulation of LH secretion at the pituitary level.

7

The expression of genes encoding opioid precursors and the influence of opioid receptor agonists on steroidogenesis in porcine adrenocortical cells in vitro

51%

Krazinski B. E., Koziorowski M., Brzuzan P., Okrasa S.

Journal of Physiology and Pharmacology

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2011

|

tom 62

|

nr 4

8

The potential implication of neurokinin B in the modulation of prolactin secretion at the pituitary level in cyclic gilts

51%

Czelejewska W., Zmijewska A., Dziekonski M., Okrasa S.

Journal of Physiology and Pharmacology

|

2020

|

tom 71

|

nr 2

9

Mechanizmy laktacyjnej niepłodności u loch

51%

Dusza L., Kotwica G., Okrasa S.

Zeszyty Problemowe Postępów Nauk Rolniczych

|

1987

|

tom 339

10

Primary antisera against selected steroids or proteins and secondary antisera against gamma-globulins – an available tool for studies of reproductive processes

51%

Szafranska B., Ziecik A., Okrasa S.

Reproductive Biology

|

2002

|

tom 02

|

nr 2

11

The effects of mu-, delta- and kappa-opioid receptor activation on luteinizing and follicle-stimulating hormone secretion from porcine pituitary cells

51%

Wylot B., Tworus K., Okrasa S.

Journal of Physiology and Pharmacology

|

2013

|

tom 64

|

nr 4

12

Influence of opioids on LH secretion in gilts during the estrous cycle

51%

Okrasa S., Kalamarz H., Tilton J. E., Ziecik A. J.

Journal of Physiology and Pharmacology. Supplement

|

1992

|

tom 43

|

nr 1

13

Modulatory effects of steroid hormones, oxytocin, arachidonic acid, forskolin and cyclic AMP on the expression of aquaporin 1 and aquaporin 5 in the porcine uterus during placentation

45%

Skowronska A., Mlotkowska P., Okrasa S., Nielsen S., Skowronski M. T.

Journal of Physiology and Pharmacology

|

2016

|

tom 67

|

nr 2

14

The effects of mu-, delta- and kappa-opioid receptor activation on in vitro prolactin secretion by anterior pituitary cells of cyclic gilts

45%

Kosciukiewicz K., Wylot B., Czelejewska W., Gilun P., Okrasa S.

Journal of Animal and Feed Sciences

|

2018

|

tom 27

|

nr 2

The aim of the study was to determine an in vitro effect of specific agonists of opioid receptors on basal prolactin secretion and in the presence of dopamine or thyreoliberin (TRH) by porcine anterior pituitary cells. The cells were isolated from anterior pituitaries of gilts on days 8–10, 15–17 and 19–21 of the oestrous cycle and submitted to in vitro culture with mu-, delta- and kappaopioid receptor agonists – FK 33-824, DPLPE and U 50,488, respectively. Differentiated effects of the opioid agonists on prolactin secretion by isolated pituitary cells of gilts in chosen days of the oestrous cycle were shown. In the midluteal phase (days 8–10), a reduced prolactin secretion was demonstrated after activation of mu-, delta- and kappa-opioid receptors under all tested conditions. In the early follicular phase (days 15–17), the activation of mu-, delta- and kappa-opioid receptors increased prolactin secretion under basal conditions, as well as mu- and delta-opioid receptors – in the presence of TRH, but the stimulation of mu- and kappa-opioid receptors reduced the hormone secretion in the presence of dopamine. In the late follicular phase (days 19–21), kappa-opioid receptor agonist stimulated prolactin secretion under all tested conditions. The activation of mu- and delta-opioid receptors increased prolactin secretion under basal conditions and in the presence of dopamine, but decreased – in the presence of TRH. The results suggest a possibility of diverse participation of endogenous opioids, depending on stage of the oestrous cycle, in the modulation of prolactin secretion at the pituitary level in gilts during the oestrous cycle.

15

Udzial opioidow w lokalnej regulacji funkcji jajnika

45%

Przala J., Kaminski T., Okrasa S., Siawrys G., Bogacka I.

Postępy Biologii Komórki. Suplement

|

1999

|

tom 12

113-116

16

Effects of mating stimuli and oxytocin on plasma cortisol concentration in gilts

45%

Kotwica G., Franczak A., Okrasa S., Koziorowski M., Kurowicka B.

Reproductive Biology

|

2002

|

tom 02

|

nr 1

17

The effect of selective agonists of opioid receptors on in vitro secretion of steroid hormones by porcine endometrium during the estrous cycle and early pregnancy

45%

Dziekonski M., Zmijewska A., Czelejewska W., Wojtacha P., Okrasa S.

Journal of Physiology and Pharmacology

|

2018

|

tom 69

|

nr 5

18

The involvement of adenylyl cyclase and protein kinase A in the mechanism of opioid peptide action in porcine theca interna cells

45%

Kaminski T., Siawrys G., Bogacka I., Okrasa S., Przala J.

Cellular and Molecular Biology Letters

|

2002

|

tom 07

|

nr Suppl.

19

Gene expression and peptide localization for LH-hCG receptor in porcine small and large luteal cells: possible regulation by opioid peptides

45%

Kaminski T., Gawronska B., Derecka K., Okrasa S., Przala J.

Journal of Physiology and Pharmacology

|

2000

|

tom 51

|

nr 2

20

The influences of GnRH, oxytocin and vasoactive intestinal peptide on LH and PRL secretion by porcine pituitary cells in vitro

45%

Bogacka I., Siawrys G., Okrasa S., Kaminski T., Przala J.

Journal of Physiology and Pharmacology

|

2002

|

tom 53

|

nr 3

The aim of the present study was to evaluate the possible direct effects of GnRH, oxytocin (OT) and vasoactive intestinal peptide (VIP) on the release of LH and PRL by dispersed porcine anterior pituitary cells. Pituitary glands were obtained from mature gilts, which were ovariektomized (OVX) one month before slaughter. Gilts randomly assigned to one of the four groups were treated: in Group 1 (n=8) with 1 ml/100 kg b.w. corn oil (placebo); in Group 2 (n=8) and Group 3 (n=8) with estradiol benzoate (EB) at the dose 2.5 mg/100 kg b.w., respectively, 30-36 h and 60-66 h before slaughter; and in Group 4 (n=9) with progesterone (P4) at the dose 120 mg/100 kg b.w. for five consecutive days before slaughter. In gilts of Group 2 and Group 3 treatments with EB have induced the negative and positive feedback in LH secretion, respectively. Isolated anterior pituitary cells (106/well) were cultured in McCoy's 5a medium with horse serum and fetal calf serum for 3 days at 37°C under the atmosphere of 95% air and 5% CO2. Subsequently, the culture plates were rinsed with fresh McCoy's 5A medium and the cells were incubated for 3.5 h at 37°C in the same medium containing one of the following agents: GnRH (100 ng/ml), OT (10-1000 nM) or VIP (1-100 nM). The addition of GnRH to cultured pituitary cells resulted in marked increases in LH release (p<0.001) in all experimental groups. In the presence of OT and VIP we noted significant increases (p<0.001) in LH secretion by pituitary cells derived from gilts representing the positive feedback phase (Group 3). In contrast, OT and VIP were without any effect on LH release in Group 1 (placebo) and Group 2 (the negative feedback). Pituitary cells obtained from OVX gilts primed with P4 produced significantly higher amounts (p<0.001) of LH only after an addition of 100 nM OT. Neuropeptide GnRH did not affect PRL secretion by pituitary cells obtained from gilts of all experimental groups. Oxytocin also failed to alter PRL secretion in Group 1 and Group 2. However, pituitary cells from animals primed with EB 60-66 h before slaughter and P4 produced markedly increased amounts of PRL in the presence of OT. Neuropeptide VIP stimulated PRL release from pituitary cells of OVX gilts primed with EB (Groups 2 and 3) or P4. In contrast, in OVX gilts primed with placebo, VIP was without any effect on PRL secretion. In conclusion, the results of our in vitro studies confirmed the stimulatory effect of GnRH on LH secretion by porcine pituitary cells and also suggest a participation of OT and VIP in modulation of LH and PRL secretion at the pituitary level in a way dependent on hormonal status of animals.

Ograniczanie wyników

Changes of progesterone level is the plasma of sows during the estrous cycle

Poziom ACTH i kortykoidów w cyklu płciowym u loszek

Postęp w badaniach dotyczących procesów rozrodczych u świń

Oxytocin plasma level in the lactating sows - effect of suckling

Opioid antagonist and agonist effects on GnRH release in vitro from the SME of ovariectomized gilts primed with steroids

The expression of genes coding for opioid precursors, opioids receptors, beta-LH subunit and GnRH receptor in the anterior pituitary of cyclic gilts

The expression of genes encoding opioid precursors and the influence of opioid receptor agonists on steroidogenesis in porcine adrenocortical cells in vitro

The potential implication of neurokinin B in the modulation of prolactin secretion at the pituitary level in cyclic gilts

Mechanizmy laktacyjnej niepłodności u loch

Primary antisera against selected steroids or proteins and secondary antisera against gamma-globulins – an available tool for studies of reproductive processes

The effects of mu-, delta- and kappa-opioid receptor activation on luteinizing and follicle-stimulating hormone secretion from porcine pituitary cells

Influence of opioids on LH secretion in gilts during the estrous cycle

Modulatory effects of steroid hormones, oxytocin, arachidonic acid, forskolin and cyclic AMP on the expression of aquaporin 1 and aquaporin 5 in the porcine uterus during placentation

The effects of mu-, delta- and kappa-opioid receptor activation on in vitro prolactin secretion by anterior pituitary cells of cyclic gilts

Udzial opioidow w lokalnej regulacji funkcji jajnika

Effects of mating stimuli and oxytocin on plasma cortisol concentration in gilts

The effect of selective agonists of opioid receptors on in vitro secretion of steroid hormones by porcine endometrium during the estrous cycle and early pregnancy

The involvement of adenylyl cyclase and protein kinase A in the mechanism of opioid peptide action in porcine theca interna cells

Gene expression and peptide localization for LH-hCG receptor in porcine small and large luteal cells: possible regulation by opioid peptides

The influences of GnRH, oxytocin and vasoactive intestinal peptide on LH and PRL secretion by porcine pituitary cells in vitro