Udział hormonu wzrostu w regulacji czynności jajnika kury (Gallus gallus domesticus)
AbstractGrowth hormone (OH) produced mainly by the pituitary gland plays a key role in growth regulation, cell differentiation and metabolism control. In mammals it also takes part in the regulation of reproductive functions. The participation of GH in ovarian activity in birds has received little attention. Although GH and its receptor (GHR) have been shown to appear in the chicken ovary, the direct action of GH on the ovary has not been examined. Therefore, the question has arisen whether OH has physiological significance to the local regulation of chicken ovary development and activity. In the initial experiments the changes in GHR expression were examined in the chicken ovary during sexual maturation and ovulatory cycle. To answer the question whether GH action in the ovary may be connected with the regulation of steroidogenesis, the levels of progesterone (P4) and estradiol (E2) were determined in the ovary and blood plasma of hens after recombinant chicken GH (cGH) administration during sexual maturation. In addition, the effect of cGH on LH—stimulated steroids (P4 and E2) secretion by intact ovarian follicles of immature and mature chickens, and the separated granulosa and theca layers of preovulatory follicles in vitro was examined. To find out whether the GH effect is related to the regulation of gonadotropins receptors expression, the FSH and LH receptors mRNA was determined in the growing chicken ovary after cGH administration. In order to investigate whether the GH participation in ovary development and activity may be the result of its effect on proliferation and/or apoptosis processes, the proliferating and apoptotic cells were localised in the ovarian compartments, and the expression of antiapoptotic Bc1-2 protein and caspase-3 was examined in the hen ovary during maturation after cGH treatments. Gene expression in tissues was determined by RT-PCR method. Steroids concentration in plasma, tissues and medium was assayed radioimmunologically. Proliferating cells (PCNA-positive) were localised immunocytochemically and apoptotic cells were localised by TUNEL. During sexual maturation the expression of GHR mRNA occurred in the ovarian stroma containing primordial follicles
|Other language title versions||Participation of growth hormone in the regulation of the ovarian function in the hen (Gallus gallus domesticus)|
|Publisher||Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie, MNiSW |
|Publishing place (Publisher address)||Kraków|
|Book series /Journal (in case of Journal special issue)||Zeszyty Naukowe Uniwersytetu Rolniczego im. Hugona Kołłątaja w Krakowie. Rozprawy, ISSN 1899-3486, (0 pkt)|
|Publication size in sheets||7|
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