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Öğe Distribution and heterogeneity of mast cells in female reproductive tract and ovary on different days of the oestrus cycle in Angora goats(Wiley-Blackwell, 2008) Karaca, T.; Arikan, S.; Kalender, H.; Yoruk, M.The physiological distribution of mast cells (MCs) in the reproductive tract and ovary of 12 Angora goats was determined using light microscopic histochemical techniques. Uterus (corpus uteri and cornu uteri), uterine cervix, uterine tubes (isthmus and ampulla) and ovary samples were obtained by laparatomy from groups of animals during metoestrus, dioestrus and proestrus (days 5, 10 and 16 of the oestrous cycle). Tissues were fixed in Mota's fixative (basic lead acetate) for 48 h and embedded in paraffin. Six-micrometre-thick sections were stained with toluidine blue in 1% aqueous solution at pH 1.0 for 5 min and alcian blue-Safranin at pH 1.0 for 30 min. MCs were generally associated with blood vessels in all reproductive organs. In the uterus, they were concentrated mainly in the close of the uterine gland and deep stroma in the endometrium. Higher MC numbers were observed by toluidine blue staining in the uterus, uterine cervix and uterine tubes on days 10 (corpus uterine: 4.7 +/- 3.8 and cornu uterine: 4.9 +/- 3.5) and 16 (corpus uterine: 5.9 +/- 4.5 and cornu uterine: 5.4 +/- 2.4) of the oestrous cycle compared with day 5 (p < 0.05). Mast cells were not observed in the follicles, the corpus luteum and the underside of the surface epithelium of the ovarian cortex, but were observed in the interstitial cortical stroma and the ovarian medulla. In the ovary, MC numbers were significantly higher on day 16 of the oestrous cycle (cortex: 3.4 +/- 2.4 and medulla: 5.7 +/- 4.5, p < 0.05). Safranin-positive connective tissue MCs were not observed in the uterine tube on any occasion. These results indicate oestrous cycle-related changes in the number and location of MCs in goat reproductive organs.Öğe Effects of Cholesterol on Progesterone Production by Goat Luteal Cell Subpopulations at Two Different Stages of the Luteal Phase(Wiley-Blackwell Publishing, Inc, 2010) Arikan, S.; Kalender, H.; Simsek, O.Contents The aim of the present study was to evaluate the effects of cholesterol on progesterone production during long-term culturing of luteal cell subpopulations at early and late luteal stages of the goat corpora lutea. Corpora lutea were collected from Angora goats on days 5 and 15 of the oestrous cycle. Luteal cells were isolated by collagenase digestion. The cells were separated into two distinct subpopulations by Percoll density-gradient centrifugation. Both subpopulations of luteal cells staining positively for 3 beta-HSD activities (5 x 104 cell/well) were cultured with or without 22(R)-hydroxycholesterol (22R-HC) in serum-free culture medium for periods of up to 7 days. Cells were incubated with serum (10%) for the first 18 h of incubation followed by serum-free medium. Cell treatment (10 and 20 mu g/ml) was performed on days 1, 3 and 5. Treatment of cells with both concentrations of 22R-HC resulted in significant (p < 0.01) and dose-dependent stimulation (p > 0.05) on progesterone production in both fractions of cells throughout 7 days of incubation. Treatment of the cells with cholesterol resulted in 2.5- and 9.0-fold increases in progesterone accumulation on day 3 of incubation. Steroid production was maintained throughout the incubations when cells are incubated in serum-free media treated with cholesterol and ITS premix. Cells collected from higher density of percoll layers produced 2.82 and 2.32 times more progesterone, in comparison to the lover density percoll layer, on days 5 and 15 of the oestrous cycle in untreated cell groups, respectively. Progesterone accumulation was decreased as incubation time advanced in all groups of untreated cells. These results demonstrated that goat luteal cell subpopulations secrete substantial amounts of progesterone in response to cholesterol treatment at least for 7 days, and cholesterol is required as progesterone precursor for maintaining a high-level steroidogenesis during long-life culturing of both cell subpopulations.Öğe Effects of cholesterol, FSH and LH on steroidogenic activity in cat granulosa cell culture(Wiley-Blackwell, 2014) Simsek, O.; Arikan, S.…Öğe Effects of cholesterol, FSH and LH on steroidogenic activity of cat granulosa cells cultured in vitro(Brazilian Coll Animal Reproduction, 2015) Simsek, O.; Arikan, S.The aim of this study was to examine the effects of 22R-hydroxycholesterol (22R-HC), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on estradiol and progesterone production by cat granulosa cells. Granulosa cells from follicles were collected and cultured for up to 5 days in 24 well plates containing Dulbecco's Modified Eagle's Medium (DMEM)/HAM F-12 supplemented with 10(-7) M androstenedione, 0.1% ITS premix and 0.1% bovine serum albumin, in the presence or absence of 22R-HC (10 mu g/ml), FSH or LH (10, 100 ng/ml each) on first and third day. Additionally, 5% fetal calf serum was added into the culture medium for the first 24 h. Treatment of cells with 22R-HC resulted in an increase (P < 0.05) in progesterone and estradiol production on days 3 and 5 of the culture. Incubation of cells with FSH (10 and 100 ng/ml) resulted in significant stimulations of progesterone (P < 0.001) whilst incubation had no effect on estradiol production. None of the LH doses (10 and 100 ng/ml) had any effect on progesterone production by granulosa cells during the culture time. With the inclusion of 22R-HC into the culture system, progesterone synthesis was enhanced (P < 0.001) in the presence of all FSH doses.Öğe Effects of dbcAMP on progesterone synthesis by cultured goat luteal cell subpopulations isolated from early and late luteal stage corpora lutea(Brazilian Coll Animal Reproduction, 2016) Arikan, S.; Kalender, H.; Simsek, O.This research aimed to investigate the effects of dbcAMP on steroid accumulation by culturing two distinct luteal cell subpopulations isolated from early and late luteal stage corpora lutea. Cells were isolated from corpora lutea collected from eight Angora goats on either the 5th or 15th days of their estrous cycles. Cell isolation was performed by enzymatic digestion using collagenase and DNase. Isolated cells were separated into two distinct subpopulations enriched with small and large luteal cells by percoll density-gradient centrifugation. Isolated cells were stained in order to detect 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD). Cells stained positively for 3 beta-HSD activity (5 x 10(4) cell/well) were incubated with dbcAMP in the absence or presence of 22(R)-hydroxycholesterol (22R-HC) for periods of up to 7 days. Large luteal cell enriched subpopulations produced more basal progesterone (P < 0.05) than did the small luteal cell enriched subpopulations. Treatment of cells with 22R-HC alone induced 4.00 to 11.60 times increase in steroid synthesis depending on type of cells incubated, luteal age and days of incubation. Incubation of cells with 1 mM dbcAMP in the absence or presence of 22R-HC induced in a significant increase (P < 0.01) in steroid accumulation in all treated groups. In contrast, when cells are treated with low dose dbcAMP (0.1 mM), treatment induced stimulation failed to reach significant level in most treated groups. In conclusion, although treatment of goat luteal cells with dbcAMP induces an increase in steroid accumulation, a high dose is necessary to reach significant levels. Stimulatory effect of dbcAMP on steroidogenesis maintains during long life culturing.Öğe Raman spectroscopy and imaging of β-carotene in live corpus luteum cells(Elsevier Science Bv, 2002) Arikan, S.; Sands, H.S.; Rodway, R.G.; Batchelder, D.N.Raman spectroscopy has been used to identify and locate beta-carotene within individual living luteal cells. The cells were either freshly prepared or cultured; the latter was incubated in the presence or absence of beta-carotene in the form of enriched bovine high-density lipoprotem. Luteal cells were investigated using several Raman spectroscopic and imaging techniques. These techniques did not give accurate concentration levels of beta-carotene within parts of the cell but illustrated the distribution of the molecule. Freshly prepared luteal cells were found to contain an appreciable concentration of beta-carotene. Over a period of several days, the concentration gradually reduced to a nearly undetectable level; similar results were found for cells cultured in the absence of the beta-carotene. For cells cultured in the presence of beta-carotene, the molecular concentration was maintained for as long as 2 weeks. The Raman spectra of fragmented cells showed that the beta-carotene is predominantly localised in the lipid-rich cell components, with the concentration highest in the microsomal fraction. The Raman imaging techniques revealed that beta-carotene was spread over the entire volume of the luteal cells with higher levels occurring at distinct sites, including the surface. (C) 2002 Elsevier Science B.V. All rights reserved.Öğe Size Distribution of Luteal Cells During Pseudopregnancy in Domestic Cats(Wiley, 2009) Arikan, S.; Yigit, A. A.; Kalender, H.Contents Experiments were designed to investigate the size distribution of queen steroidogenic luteal cells throughout pseudopregnancy. Corpora lutea were obtained from the queens following ovariohysterectomy on days 7, 15 or 25 of pseudopregnancy. Luteal cells were isolated from the ovary by collagenase digestion. Steriodogenic cells were identified by staining of cells for 3 beta-HSD activity. Cell diameters were measured using a microscope. Luteal cells having steroidogenic capacity covered a wide spectrum of sizes ranging from 3 to 35 mu m in diameter. There was a significant increase in mean cell diameters (p < 0.01) as pseudopregnancy progressed. Mean diameter of 3 beta-HSD positive cells increased from 10.41 +/- 0.7 mu m, on day 7 of pseudopregnancy, to 19.72 +/- 1.3 mu m on day 25 of pseudopregnancy. The ratio of large (> 20 mu m in diameter) to small (3-20 mu m in diameter) luteal cells was 0.08 : 1.0 on day 7 of pseudopregnancy, with the 7.5-10 mu m cell size class predominant. By day 25 of pseudopregnancy, the ratio of large-to-small cells was increased to 0.87 : 1.0, and 20-25 mu m cell sizes become predominant. In conclusion, this study has demonstrated that the cells of the corpus luteum undergo continuous differentiation during pseudopregnancy in queen. This study also demonstrates that luteal cells dissociated from pseudopregnant queen can be used as a model to study the physiology of corpus luteum in pregnant cats.Öğe Size distribution of steroidogenic and non-steroidogenic ovine luteal cells throughout pregnancy(British Soc Animal Science, 2002) Arikan, S.; Yigit, A.A.The present study examines the size distribution of ovine steroidogenic and non-steroidogenic luteal cells throughout pregnancy. Cells were isolated from corpora lutea collected from early (:! 8 weeks), mid (9 to 14 weeks) or late (15 to 18 weeks) stages of pregnancy. Cells were stained for 3,3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity, a marker for steroidogenic cells. Both 3beta-HSD positive and beta-HSD negative cells covered a wide spectrum of size ranging from 7 to 37mum in diameter. There was a significant increase (P > 0.01) in mean diameter of nonsteroidogenic luteal cells as pregnancy progressed. Mean diameter of 3beta-HSD negative cells increased from 17.8 (s.e. 0.4) mum in the corpus luteum of early stage of pregnancy to 22.4 (s.e. 0.3) mum in the corpus luteum of advanced pregnancy. However, there was no significant increase in the mean diameter of 3beta-HSD positive cells. Corpora lutea obtained from early stages of the pregnancy contained more steroidogenic cells than the cells obtained from mid and late pregnancy (P < 0.01). Percentage of 3beta-HSD negative cells had increased 2.07-fold by 18 weeks of pregnancy when compared with the early stage of pregnancy. In contrast, percentage of 3,3beta-HSD positive cells had decreased to 50% of starting values during the same period (P < 0.05). These results indicate that the ovine corpus luteum of pregnancy is morphologically dynamic over the course of pregnancy. Steroidogenic activity of luteal cells may decrease as pregnancy progresses, especially activity of the large luteal cells.
