r e p r o d u c t i v e b i o l o g y 1 3 s ( 2 0 1 3 ) 3 0 – 4 5 43

the localization and changes in the expression of AQP1, 5 and 9 within porcine uterine slices harvested during early pregnancy

(Days 30-32) and luteal phase (Days 14-16). The slices were incubated for 3- or 24-h in the presence of progesterone (P4),

estradiol (E2), oxytocin (OT), arachidonic acid (AA), forskolin (FSK), and cyclic AMP (cAMP). Immunohistochemical analysis was

used to examine the distribution and changes in amounts of studied AQPs in cells of the pig uterus. AQP1 immunoreactivity

was detected within uterine blood vessels. AQP5 was mainly localized in smooth muscle cells and uterine epithelial cells. The

anti-AQP9 antibody labeled uterine epithelial cells of uterus. Progesterone and E2 induced AQP5 expression in the cyclic group

after 3- and 24-h treatments and in the 24-h pregnant group. AQP1 and AQP5 expression increased significantly after both

treatments and after 24-h treatment with FSK and cAMP in cyclic and pregnant gilts, respectively. The expression of AQP1 and

AQP5 was induced by 3-h treatment with AA. AQP9 expression did not change significantly in the all studied groups. Moreover,

OT did not affect the expression of AQPs. This study, for the first time, shows that the regulation of AQPs occurs in the pig

uterus in in vitro study. Together these results may provide novel information concerning the mechanism by which hormonal

environment controls water imbibition and luminal fluid viscosity in the pig uterus during the estrous cycle and early

pregnancy.

This research was supported by the Polish Ministry of Science and Higher Education (grant numbers N N308 5848 40 and 528-0206.806)

http://dx.doi.org/10.1016/j.repbio.2012.11.045

[P35] In vitro effect of resistin on protein expression of peroxisome proliferator activated receptor (PPAR-g) in cultured porcine

ovarian follicles

Agnieszka Rak-Mardyła *, Anna Karpeta

Department of Physiology and Toxicology of Reproduction, Institute of Zoology, Jagiellonian University, Krakow

*Corresponding author.

Resistin is a circulating 12.5 kDa protein of 114 amino acids that belongs to the resistin-like family. Resistin mRNA has been

found in human adipose tissue and also in bone marrow, lung, nonfat cells of adipose tissue, placental tissue and ovary. Last

paper showed a connection between resistin and reproduction function. Moreover, resistin identified as a potential target of

synthetic ligands of PPAR receptor in adipocyte. PPAR-g belongs to peroxisome proliferator activated receptor family, which also

includes PPARa and PPARb/d. PPAR-g is activated by natural (prostaglandin metabolites) or synthetic (thiazolidinediones)

ligands. Recent studies have shown that activation of PPAR-g receptor regulates fat tissue mass, cell proliferation and

inflammatory reactions. Three PPARs isoforms are expressed in reproductive tissues: ovary, testis, uterus, prostate, and

mammary gland. The activation of PPAR-g can also influence steroid hormone production by ovarian cells and female fertility.

In the present study we examined in vitro effect of resistin on PPAR-g protein expression in the ovary. Porcine ovarian follicles

(small, medium and large) collected from prepubertal and estrus cycle were cultured in the presence or absence of resistin

(0.1, 1 and 10 ng/ml) in M199 medium/5% FBS during 24 h. After incubation, protein expression of PPAR-g was measured using

Western blot. Results of the presented study show that resistin stimulates PPAR-g protein expression in all type of ovarian

follicles collected from both prepubertal and estrus cycle. Our study suggests local interaction between resistin and PPAR-g

receptor in ovarian follicles.

Supported by the Budget of Sciences from 2012-2014 as a project 04447/IP1/2011/71 Iuventus Plus

http://dx.doi.org/10.1016/j.repbio.2012.11.046

[P36] Direct in vitro effect of LH and steroids on leptin secretion by porcine luteal cells during the late-luteal phase of the estrous

cycle

Gabriela Siawrys

Department of Animal Physiology, University of Warmia and Mazury, Olsztyn-Kortowo

Leptin, the product of the ob gene, is implicated in the control of reproductive functions in different species. Leptin transcript and

protein are present in several tissues including adipose tissue and corpus luteum. The regulation of leptin secretion in porcine

luteal cells is not clear.

The aim of these studies was: 1] to examine, in vitro, the effects of LH, 17-b estradiol (E2) and progesterone (P4) on leptin secretion by

porcine luteal cells during the late-luteal phase of the oestrous cycle and 2] to determine leptin protein expression levels in those

cells on days 14-16 of the cycle. Luteal cells after preliminary culture (48 h) were treated with LH (1; 10; 100 ng/ml), E2 (0.02; 0.2; 2; 20

ng/ml) and P4 (20; 100; 200 ng/ml) for 24 h. Leptin concentrations in the media samples were measured using a leptin RIA kit. The

expression of leptin protein was determined by fluorescence immunocytochemistry. It was shown that: 1] LH, E2 and P4 did not

induce significant changes in leptin release by porcine luteal cells on days 14-16 of the oestrous cycle; 2] leptin protein expression

is localised in porcine luteal cells during this period. The results of the present study indicate that leptin protein is expressed in

porcine luteal cells and suggest that LH and steroids are not involved in the regulation of leptin secretion by porcine luteal cells

during the late-luteal phase of the oestrous cycle.

This research was supported by the Ministry of Science and Higher Education (Project: N N311 098634)

http://dx.doi.org/10.1016/j.repbio.2012.11.047