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1

Effects of ultrafiltration fractions of Sertoli cell culture medium on FSH and LH secretion by pituitary cells in vitro

100%
Janecki A., Lukaszyk A.
Folia Histochemica et Cytobiologica
|
1984
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tom 22
|
nr 3-4
2
Content available remote

Effect of leptin on thyroid-stimulating hormone secretion and nitric oxide release from pituitary cells of ewe lambs in vitro

100%
Radwanska P., Kosior-Korzecka U.
Journal of Physiology and Pharmacology
|
2014
|
tom 65
|
nr 1
3
Content available remote

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

100%
Bogacka I., Siawrys G., Okrasa S., Kaminski T., Przala J.
Journal of Physiology and Pharmacology
|
2002
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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.
4

How ASS-52 and ASS-71 Arg, the new analogues of somatostatin affect secretion of rats pituitary cells - in vitro study

100%
Kawalec M., Chmielowska M., Radzikowska M., Baranowska B. B.
Folia Histochemica et Cytobiologica. Supplement
|
1997
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tom 35
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nr 2
5
Content available remote

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

84%
Wylot B., Tworus K., Okrasa S.
Journal of Physiology and Pharmacology
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2013
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tom 64
|
nr 4
6

Effect of leptin, insulin, and IGF-I on GnRH-induced LH secretion from porcine pituitary cells in vitro

84%
Kosior-Korzecka U., Bobowiec R.
Bulletin of the Veterinary Institute in Puławy
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2007
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tom 51
|
nr 3
The objective of this study was to analyse the response of porcine pituitary cells to leptin, insulin, and IGF-I in vitro. Pituitary cells were cultured in McCoy 5A medium without hormones (negative control), with GnRH (4x10⁻⁹M/L) (positive control), with GnRH and 10⁻¹¹-10⁻⁶ M/L of leptin, with GnRH and 3.9-91.0 mlU/L of insulin, or with GnRH and 1.03-39.2x10⁻⁹ M/L of IGF-I. After 6, 12, 18, 24, 30, and 36 h of cell incubation, the secretion of LH was determined. The obtained results showed that the effect of leptin and insulin on LH secretion from pituitary cells was dependent on the used dose of leptin. Leptin in concentrations 10⁻⁹, 10⁻⁸, and 10⁻⁷ M/L were significantly (P≤0.05) enhanced, whereas in concentration 10⁻⁶ M/L suppressed a LH secretion. Insulin at a dose from 3.9 to 13.0 mlU/L caused an increment, whereas in higher concentrations - a significant (P≤0.05) drop in LH secretion. Almost full positive correlation (r=0.98) between the level of IGF-I in the culture medium and LH secretion was found.
7

Interaction of ghrelin and opioids in luteinizing hormone (LH) secretion by pituitary cells of common carp, Cyprinus carpio (Actinopterygii: Cypriniformes: Cyprinidae), cultured in vitro

67%
Sokolowska-Mikolajczyk M., Socha M., Mikolajczyk T., Epler P., Falowska B.
Acta Ichthyologica et Piscatoria
|
2011
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tom 41
|
nr 2
Background. Ghrelin, a newly discovered hormone is involved mainly in the regulation of body energy homeostasis. It has also been proved that ghrelin affects many other processes including the control of the hypothalamo-pituitary-gonadal axis in vertebrates. Ghrelin interacts also with other peptides and neurotransmitters, which are involved in gonadotropin release, such as endogenous opioid peptides. The aim of the experiment was to compare the effects of ghrelin and naltrexone, an opioid antagonist, on LH secretion by pituitary cells of mature female and male common carp, Cyprinus carpio L. Materials and methods. In the in vitro experiment the time-dependent (10 and 24 h) action of ghrelin (10-7 or 10-6 M) and naltrexone at 10-6 M added alone or in combination on LH secretion by enzymatically dispersed pituitary cells of mature female and male carp (Cyprinus carpio L.) was studied. Results. Ghrelin alone at a dose of 10-6 M stimulated LH secretion after 10 h of female- but not male-derived cell incubations. Ghrelin at 10-7 M had no effect on LH secretion from either female or male cells. Naltrexone alone stimulated LH secretion only after 24 h of female cell culture. In male cells no significant changes in LH secretion in response to naltrexone alone were found after 10 or 24 h incubation period. Combined treatment (ghrelin 10-7 or 10-6 M and naltrexone) stimulated LH secretion in female and male cell incubations at 10 and 24 h: LH levels were significantly higher in comparison to control, to ghrelin alone (in cells of both sexes) and to naltrexone alone (in male cells only). Conclusion. The results suggest that opioids and ghrelin may control LH secretion in carp acting synergistically, probably through the same receptor type. The concept of opioid and ghrelin interaction in the gonadal steroid feedback on LH release is also discussed.
8
Content available remote

Additional effects of bisphenol A and paraben on the induction of calbindin-D9k and progesterone receptor via an estrogen receptor pathway in rat pituitary GH3 cells

67%
Kim S. M., Jung E. M., An B. S., Hwang I., Vo T. T., Kim S. R., Lee S. M., Choi K. C., Jeung E. B.
Journal of Physiology and Pharmacology
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2012
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tom 63
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nr 5
9

Naltrexone stimulates LH secretion in vitro from the common carp [Cyprinus carpio L.] pituitary gland

67%
Socha M., Sokolowska-Mikolajczyk M., Mikolajczyk T., Chyb J., Epler P.
Archives of Polish Fisheries
|
2003
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tom 11
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nr 1
The effects of naltrexone on the in vitro luteinizing hormone (LH) secretion from whole pituitary glands as well as from dispersed pituitary cells of common carp (Cyprinus carpio L.)in primary cell culture were studied. The perifusion of whole pituitary glands with naltrexone at a concentration of 10⁻⁴ M caused a significant increase of LH secretion compared to the control. This finding suggests that opioid peptides can indirectly affect LH secretion at the pituitary level, probably through the nerve terminals containing GnRH and/or DA present in the pituitary. In the perifusion of dispersed pituitary cells with naltrexone at concentrations of 10⁻⁶ or 10⁻⁴ M, significant increases of LH levels were found. Similar results were observed in static culture of dispersed carp pituitary cells: after 4 or 24 hours of culture in the medium containing naltrexone at concentrations of 10⁻⁶, 10⁻⁴ or 10⁻² M,a dose-dependent, statistically significant increase of LH secretion to the culture medium was found. The results from dispersed pituitary cell perifusions or cell culture with naltrexone indicate that this antagonist directly affects the pituitary cells and stimulates LH release from carp gonadotrophs.
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