Balogh Reichler Kowalewski
Fakultäten » Vetsuisse-Fakultät » Nutztiere, Departement für » Reproduktionsmedizin, Klinik für » PD Dr. Iris Reichler » Balogh Reichler Kowalewski
Current research project
| Title / Titel | Reproductive tissue expression of leptin, IGF-I, their receptors and the insulin receptor during pregnancy and the non-pregnant diestrous phase in the bitch | ||||||
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| Abstract (PDF, 14 KB) | |||||||
| Summary / Zusammenfassung | Leptin is a primarily adipocyte-derived polypeptide hormone and its serum levels parallel the amount of fat reserves also in dogs. Leptin controls food intake and energy expenditure as well as reproductive processes at the level of the hypothalamus and the pituitary. Leptin and leptin receptors (lepR, the long form appears to be the main mediator of cellular action) are also expressed in reproductive tissues e.g. the ovary, endometrium, placenta, mammary gland, suggesting a direct autocrine/ paracrine role. Leptin may have a modulatory effect on granulosa, theca and luteal cell steroidogenesis either alone or modulating the synergistic effects of insulin and IGF-I on FSH and LH induced steroidogenesis. Leptin might play a pivotal role in implantation, placental secretory capacity and growth and fetal growth. Plasma leptin levels were not different between male and female dogs irrespective of their BCS in one report, but were higher in females than in males in another study. The same authors found higher peripheral levels during estrus than proestrus and diestrus. Leptin protein has been detected immunohistochemically using rabbit polyclonal antibody against human leptin in the canine ovary with abundance in granulosa cells of mature luteinized follicles and even more in the CL. Leptin receptors were localized in the oocyte, in granulosa and theca cells of growing follicles and in luteinized granulosa cells, but not in the CL. The reproductive cycle of the bitch is different from many other domestic and laboratory animal species and from humans as the lifespan of the gestational and non-pregnant CL are similar and P4 production during pregnancy is exclusively CL dependent. Therefore, different regulatory processes may be involved in maintenance of the CL and the players involved may have different roles. Data are scarce in the literature regarding the involvement of leptin in reproduction in the dog and its interrelationship with other metabolic hormones like insulin and IGF-I. Our objectives are to investigate leptin, IGF-I and their receptors as well as insulin receptor expression in reproductive tissues of the pregnant and non-pregnant diestrus bitch and characterize any association that might exist between them. |
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| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Universität Zürich (position pursuing an academic career) |
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| Duration of Project / Projektdauer | Jul 2011 to Jul 2014 |