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VOLUME 8, NUMBER 2
ABSTRACTS
Native and recombinant bovine placental lactogens
Andrea V. Alvarez-Oxiley, Noelita M. de Sousa, Jean-François Beckers1
Laboratory of Endocrinology and Animal Reproduction, Faculty of Veterinary Medicine, University of Liege, Belgium
Summary
The bovine placenta produces a wide variety of proteins that are structurally and functionally similar to the pituitary proteins from the GH/PRL gene family.
Bovine placental lactogen (bPL) is a 200-amino acid long glycoprotein hormone that exhibits both lactogenic and somatogenic properties. The apparent molecular masses of
purified native (n) bPL molecules (31-33 kDa) exceed 23 041 Da, which is the theoretical molecular mass of the protein core. At least six isoelectric variants (pI: 4.85-6.3)
of bPL were described in cotyledonary extracts and three different bPL isoforms (pI: 4.85-5.25) were found in fetal sera. The bPL molecules that are detected in higher
concentrations in peripheral circulation exhibit a more acidic pI than those present in placental homogenates. This may reflect an important glycosylation process occurring
just prior to the bPL secretion. The bPL mRNA is transcribed in trophectoderm binucleate cells starting from Day 30 of pregnancy until the end of gestation. In mothers, bPL
is involved in the regulation of ovarian function, mammogenesis, lactogenesis, and pregnancy stage-dependent adaptation of nutrient supplies to the fetus. Due to the higher
fetal, compared to maternal concentrations of circulating hormone, it has been suggested that bPL primarily targets fetal tissues.
Reproductive Biology 2008 8 (2): 85-106
1Corresponding author: Laboratory of Animal Endocrinology and Reproduction, Faculty of Veterinary Medicine, University of Liege, Bd. de Colonster, 4000. Liege, Belgium:
e-mail: jfbeckers@ulg.ac.be
Decreased expression of pigment epithelium derived factor (PEDF), an inhibitor of angiogenesis, in placentas of unexplained stillbirths
Beth A. Plunkett1,2, Philip Fitchev3, Jennifer A. Doll3, Susan E. Gerber2, Mona Cornwell3, Emily P. Greenstein2, Susan E. Crawford3
2Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA;
33Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
Summary
Normal placental vascular development depends upon the complex interactions between angiogenic inducers and inhibitors within the placenta.
Alterations within the placental microenvironment can promote an imbalance in angiogenic mediators which may be associated with adverse perinatal outcomes.
The purpose of this study was to investigate the placentas of infants with unexplained stillbirth as compared to live-born infants and to determine whether
alterations in angiogenic inducer vascular endothelial growth factor (VEGF) or inhibitor pigment epithelium-derived factor (PEDF) are associated with altered
angiogenesis, vascular remodeling and stillbirth. Placentas of 22 unexplained stillbirths and 44 age-matched live-born controls were scored for microvascular density (MVD),
vasculopathy and microvascular permeability. A subset was scored for expression of angiogenic inducer VEGF and inhibitor pigment epithelium-derived factor. Stillborn placentas
demonstrated higher MVD than controls (mean+SD: 116.6±46.3 v. 60.8±13.5, respectively, p<0.001). Vasculopathy was present in 10/22 (45%) stillbirths compared to 0/44 (0%)
controls (p<0.001); increased vascular permeability was present in 15/22 (68%) cases and 5/44 (11%) controls (p<0.001). PEDF expression was significantly lower in stillborn
placentas (1.7±0.3) than live-born controls (3.6±0.8, p<0.01) while VEGF expression was similar (3.3±0.7 v. 3.7±0.4, respectively, p>0.05). In conclusion, we found that
unexplained stillbirth is associated with loss of angiogenic inhibitor PEDF, vasculopathy and heightened angiogenesis in the placenta.
Reproductive Biology 2008 8 (2): 107-120
1Corresponding author: Northwestern University Feinberg School of Medicine, 250 E. Superior St., Suite 05-2175, Chicago, IL 60611, USA:
e-mail: p-beth@northwestern.edu
The influence of steroid hormones on in vitro NOx production by porcine fetal membranes
Aneta Andronowska1, Marcin Chrusciel
Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland
Summary
The aim of the study was to examine: 1/ allantochorial concentrations of nitrate/nitrite (NOx) and 2/ plasma concentration of NOx in pigs
on days 25, 35, 40 and 60 of pregnancy as well as 3/ the influence of estradiol-17β (E2) and/or progesterone (P4) on NOx production by porcine fetal
membranes on the studied days of pregnancy. Total NOx concentration was determined using a microplate assay method based on the Griess reaction. Fetal
membrane NOx content gradually increased from day 25 to day 60 of gestation. Blood plasma NOx concentration decreased from day 25 to 40, and then plasma
NOx concentration significantly increased on day 60. In addition, the stimulatory effect of E2, P4 and E2+P4 on NO in vitro production by porcine fetal
membranes was demonstrated. The stimulatory effect of steroid hormones on NOx release depended on steroid dose and day of pregnancy. It is possible that
the observed differences in the strength of the stimulatory action of E2, P4 and E2+P4 on fetal membrane NOx production are associated with an activation of
different isoforms of nitric oxide synthase.
Reproductive Biology 2008 8 (2): 121-134
1Corresponding author: Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland:
e-mail: aneta@pan.olsztyn.pl
Immune response to lytic peptides conjugated to a βCG fragment in treated BALB/C mice
Marek Bogacki1,2, Frederic M. Enright4, William J. Todd4 and William Hansel3
2Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland;
3Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA;
4Department of Veterinary Science, Agricultural Research Experimental Station, Louisiana State University, Baton Rouge, LA, USA
Summary
Hecate-βCG and Phor14-βCG(ala) are relatively short, amphipathic alpha-helical cationic peptides with the ability to destroy selectively breast,
prostate and ovarian cancer cells. Treatment with proteins and peptides frequently initiated antibody formation. Short peptides may minimize the risk of the
immune system mobilization after treatment but it is necessary to investigate whether Hecate-βCG and Phor14-βCG(ala) induce the immune system to produce
antibody and whether they affect the reproductive organs in normal wild-type mice. The results of our experiments showed that specific antibodies, tested
by the enzyme-immunoassay, were not detected in the group treated with Hecate-βCG and Phor14-βCG(ala). The blood concentrations of both peptides begun to
decrease from 60 minutes after injection and after 240 minutes its levels were undetectable. Histopatho-logical examination exhibited degenerative changes
in the prostate glands and testes in males and in the ovaries and uteri of females treated with both peptides. In conclusion, our results indicate that both
relatively small and rapidly metabolized peptides are not immunogenic and can be used for further investigation as a potential cancer treatment.
Reproductive Biology 2008 8 (2): 135-147
1Corresponding author: Institute of Animal Reproduction and Food Research, PAS, Tuwima St. 10, Olsztyn 10-747, Poland:
e-mail: marbo@pan.olsztyn.pl
Changes in the GnRH mRNA and GnRH receptor (GnRH-R) mRNA levels in the hypothalamic-anterior pituitary unit of anestrous ewes after infusion of GnRH into the third cerebral ventricle
Magdalena Lapot2, Magdalena Ciechanowska1,2, Tadeusz Malewski3, Krystyna Mateusiak2, Tomasz Misztal2, Franciszek Przekop2
The effect of insulin-like growth factor-I, relaxin and luteinizing hormone on vascular endothelial growth factor secretion by cultured endometrial stromal cells on different days of early pregnancy in pigs
Monika M. Kaczmarek1,2, Agnieszka Blitek2, Dieter Schams3, Adam J. Ziecik2
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2The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jablonna, Poland;
3Museum and Institute of Zoology, Polish Academy of Sciences, Warsaw, Poland
Summary
In the present paper the role of GnRH in the ultrashort loop of the negative feedback action on GnRH secretion was evaluated on the molecular
level by the Real-time PCR technique. Specifically, the effect of GnRH infused into the third cerebral ventricle on the expression of GnRH and GnRH receptor
(GnRH-R) genes was analyzed in the hypothalamic-pituitary unit of anestrous ewes. GnRH did not significantly affect GnRH mRNA levels in the preoptic/anterior
hypothalamic area but drastically increased its level in the ventromedial hypothalamus. In addition, GnRH infusion augmented GnRH-R mRNA level in the entire
hypothalamus. In the GnRH-treated animals, anterior pituitary GnRH-R mRNA level and plasma LH concentration were also elevated. The changes in GnRH mRNA and
GnRH-R mRNA levels in the hypothalamus in response to treatment with GnRH suggest that GnRH acts differently on the stability of these transcripts. On the
basis of presented results it seems that GnRH may affect GnRH and GnRH-R biosynthesis and, consequently, GnRH/LH release.
Reproductive Biology 2008 8 (2): 149-161
1Corresponding author: The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jabłonna n. Warsaw, Poland:
e-mail: m.ciechanowska@ifzz.pan.pl
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2Division of Reproductive Endocrinology and Pathophysiology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland;
3Physiology Weihenstephan, Technical University Munich, Freising, Germany
Summary
The effect of insulin-like growth factor-I (IGF-I), relaxin (RLX) and luteinizing hormone (LH) on vascular endothelial growth factor (VEGF)
in vitro secretion by endometrial stromal cells in pigs was investigated on days 10-12 and 20-22 of gestation. LH-stimulated stromal cell secretion of
VEGF did not differ among tested days of early pregnancy. However, IGF-I- and RLX-mediated release of VEGF depended on the day of pregnancy. It seems
that IGF-I and RLX may be considered as potent activators of VEGF-mediated angiogenesis in porcine endometrium, and their action may be more pronounced
during maternal recognition of pregnancy.
Reproductive Biology 2008 8 (2): 163-170
1Corresponding author: Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland:
e-mail: moka@pan.olsztyn.pl