مطالعه ايمونوهيستوشيمي گيرنده ي هورمون هاي انسولين و IGF-I در تخمدان گاوهاي شيري

چكيده انگليسي :

43Immunohistochemical Study on the IGF I and Insulin Receptors Density in Granulosa and Theca Cells of Dairy Cows Bahareh Etesam bahareetesam@gmail com May 29 2012 Department of Animal Science College of Agriculture Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiHamid Reza Rahmani hrahmani@cc iut ac irMohammad Khorvash khorvash@cc iut ac irAbstract Reproductive traits are some of the most determinative parameters in dairy cow breeding industry and due to low level of inheritance of these attributes reproduction mechanisms are of the primeconsideration and therefore knowing the affective hormones will be in high level of priority Reproduction system activity needs the collaboration of primary and secondary reproductive hormones Growth factors and metabolic hormones like Insulin and IGF I have considerable influences on ovarianregulation Insulin and IGF I act as important mediators of follicular development steroidogenesis oocyte maturity and finally fetus growth In addition to the glucose transition to inner side of cells Insulin hormone has an mitogenic role that is very significant in the life and fertility of ovules IGF Iaffects the increase of follicle sensitivity to the Gonadotropins and causes the follicle development andovulation Regardless to the Insulin and IGF I concentration in blood the gene expression of IGF I andInsulin receptors and their densities in granulosa are effective on the follicular growth and activity andsteroids production The expression of mRNA in insulin and IGF I receptors have changed remarkably in granulosa cells and theca cells through pre antral stage to pre ovulatory antral stage As the sameway the expression of IGF receptors increases in granulosa cells and theca cells during the final levelsof follicular improvement and decreases with the start of atresia Tracking and estimating the density ofInsulin and IGF I receptors via methods like immunohistochemical technique could be helpful toimprove the understanding of the role of these hormones in reproduction In this study 30 ovaries ofdairy cattle were collected post mortem from several local slaughterhouses in Isfahan area thatcontained 20 ovaries from non fertile cattle and 10 ovaries from fertile ones with the age range of 2 7years The ovaries had been fixed with formalin 10 then for immunohistochemical and H E stainingvia Envision method appropriate paraffin blocks were chosen from samples We used one of theabcam co products with identification code ab39675 that was an anti rabbit monoclonal antibody andfirstly had cross reaction with IGF I receptor and also with Insulin receptor and its related proteins Based on the intensity and expanse of staining method the results were expounded in the Allred 8 unitsscored system The results revealed considerable statistical differences both in intensity and expanse ofstaining in density of receptors in ovary tissues of fertile and non fertile dairy cows p 0 0001 Staining expanse was notably higher in theca cells than granulosa cells The staining intensity in stromacells was more weak than the theca and granulose cells The staining intensity developed from pre antral follicles to antral follicles Receptors presence in corpus luteum and blood veins was confirmed The amount of staining in corpus albicans was nothing Finally we can conclude that the presence ofthe receptors of Insulin and IGF I hormones in ovarian cells demonstrates the effect of metabolicconditions of cattles on ovary activities so the density of these hormone receptors in ovarian tissue andaround oocyt could be consider as one of fertile or non fertile indices Keywords Dairy cattle Insulin IGF I Insulin and IGF I receptors Immunohistochemistry

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مطالعه ايمونوهيستوشيمي گيرنده ي هورمون هاي انسولين و IGF-I در تخمدان گاوهاي شيري