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Öğe Cholesterol-Loaded Cyclodextrin Enhances Osmotic Tolerance and Inhibits the Acrosome Reaction in Rabbit Spermatozoa(Elsevier Science Bv, 2010) Aksoy, Melih; Akman, Orhan; Lehimcioğlu, Necdet Cankat; Erdem, HüseyinThe effects of cholesterol-loaded cyclodextrin (CLC) treatment on the osmotic tolerance and ability to undergo the acrosome reaction of rabbit spermatozoa, with an unusually high cholesterol/phospholipid ratio in plasma membranes, were examined in two successive experiments. In the first experiment, CLC-pretreated and untreated sperm cells were exposed for 15 min to one of five fructose solutions, adjusted to 20, 80, 290, 500 or 1500 mOsm/L. After the anisoosmotic challenge, the integrity of sperm membranes in the CLC-supplemented (at a dose level of 3 mg/120 x 10(6) spermatozoa) and control groups was estimated by a modified hypoosmotic swelling test (HOST) associated with a supravital eosin staining test (HE-test). In the second part of the study, the influence of cholesterol supplementation on the acrosome reaction of sperm cells stimulated by either calcium ionophore A23187 (CI) or lysophosphatidylcholine (LPC) was evaluated. CLC pretreatment increased viable and live-HOST-responsive sperm rates (P<0.01) after incubation in anisoosmotic solutions varying from 80 to 1500 mOsm/L However, CLC supplementation did not influence the percentage of HOST-responsive sperm cells (P>0.05). A significant interaction was determined between CLC pretreatment and the level of osmotic pressure in maintaining the functional and physical integrities of sperm membranes undergoing osmotic challenges. Both CI and LPC successfully induced the acrosome reaction in rabbit spermatozoa (P<0.001). Compared with CI, LPC was more effective (P<0.0001). CLC pretreatment resulted in a significant reduction (P<0.01) in the percentage of acrosome reacted sperm cells irrespective of the inducing agent, either CI or LPC. In conclusion, CLC treatment enhanced the anisoosmotic tolerance of rabbit spermatozoa and reduced their ability to undergo the acrosome reaction after stimulation by CI or LPC.Öğe Effect of seminal plasma on functional integrity of rabbit sperm membranes during storage at 4 degrees C or freezing(UNIV POLITECNICA VALENCIA, 2008) Aksoy, Melih; Lehimcioğlu, Necdet Cankat; Akman, OrhanThe effect of semen plasma removal either by simple centrifugation or by separation through a Percoll gradient on the integrity of plasma membranes of rabbit spermatozoa during storage at 4 degrees C and freezing was evaluated in two successive experiments. A modified hypo-osmotic swelling test procedure combined with supravital staining was employed to evaluate simultaneously membrane integrity of head and tail membranes of sperm cells. In the first experiment, the impact of semen plasma on membrane integrity of sperm cells was examined in Tris-citric acid-glucose extender at 4 degrees C for 96 h. The percentage of sperm cells with disintegrated tail and head membranes increased in all groups in correlation with the length of storage. After storage for 96 h, removal of semen plasma, irrespective of the method of removal, resulted in significant increase (P<0.01) in the percentage of sperm cells with disintegrated plasma membranes. The adverse effect of storage and removal of semen plasma was more prominent on the tail membranes, and especially during the first 24 h of the storage period. In the second experiment, the impact of semen plasma on membrane integrity of sperm cells undergoing freezing was examined. A total of three groups were arranged as described in the first experiment, and semen samples were frozen in straws using an extender including acetamide and methyl cellulose. Freezing of semen drastically reduced the percentage of sperm cells with intact plasma membranes in post-thaw samples. However, removal of semen plasma, irrespective of the method of removal, did not affect the proportion of sperm cells with intact plasma membranes. In conclusion, the effect of semen plasma on plasma membranes varied significantly relative to the preservation temperature of sperm cells. Although it exerted a protective influence during storage at 4 degrees C, no protective impact was monitored during freezing.Öğe Effect of seminal plasma on functional integrity of rabbit sperm membranes during storage at 4°C or freezing(2008) Aksoy, Melih; Lehimcioğlu, Necdet Cankat; Akman, OrhanThe effect of semen plasma removal either by simple centrifugation or by separation through a Percoll gradient on the integrity of plasma membranes of rabbit spermatozoa during storage at 4°C and freezing was evaluated in two successive experiments. A modified hypo-osmotic swelling test procedure combined with supravital staining was employed to evaluate simultaneously membrane integrity of head and tail membranes of sperm cells. In the first experiment, the impact of semen plasma on membrane integrity of sperm cells was examined in Tris-citric acid-glucose extender at 4°C for 96 h. The percentage of sperm cells with disintegrated tail and head membranes increased in all groups in correlation with the length of storage. After storage for 96 h, removal of semen plasma, irrespective of the method of removal, resulted in significant increase (P<0.01) in the percentage of sperm cells with disintegrated plasma membranes. The adverse effect of storage and removal of semen plasma was more prominent on the tail membranes, and especially during the first 24 h of the storage period. In the second experiment, the impact of semen plasma on membrane integrity of sperm cells undergoing freezing was examined. A total of three groups were arranged as described in the first experiment, and semen samples were frozen in straws using an extender including acetamide and methyl cellulose. Freezing of semen drastically reduced the percentage of sperm cells with intact plasma membranes in post-thaw samples. However, removal of semen plasma, irrespective of the method of removal, did not affect the proportion of sperm cells with intact plasma membranes. In conclusion, the effect of semen plasma on plasma membranes varied significantly relative to the preservation temperature of sperm cells. Although it exerted a protective influence during storage at 4°C, no protective impact was monitored during freezing. © WRSA, UPV, 2003.Öğe Induction of synchronized oestrus in akkaraman cross-bred ewes during breeding and anestrus seasons: the use of short-term and long-term progesterone treatments(ECOLE NATIONALE VETERINAIRE TOULOUSE, 2006) Ataman, M. B.; Aköz, Mehmet; Akman, OrhanThe objective of this trial was to compare the efficacy of short-term and long-term progesterone treatments to induce ovarian activity of sheep both during breeding and anestrus seasons. The experiment was performed at two periods, during the breeding and the anestrus seasons on 2 different groups of 30 ewes. During each period, the ewes were randomly allocated to 2 groups of 15 ewes which received a short term (7 days) or a long term (12 days) progesterone treatment, respectively. The progesterone treatment consisted on a vaginal sponge containing 30 mg fluorogestone acetate (FGA) inserted into the vagina of the ewes for 7 or 12 days. Triaprost tromethamine, an analogue of PGF(2 alpha), was intramuscularly administered to all ewes at the moment of the sponges withdrawal. Afterwards, 400 IU of PMSG were intramuscularly administered to all the ewes. Mean percentage of estrous, pregnant and lambing sheep were 100%, 86.7 % and 80% in both the short term and the long term treated groups during the breeding season. The mean litter did not differ between the short term and the long term treated groups (1.8 vs 1.7). During the anestrus season, the mean percentage of estrous, pregnant, lambing sheep and mean litter size were 86.6%. 76.9%. 61.5% and 1.5 in the long term treated group and 93.3%. 85.7%. 71.4% and 1.5 in the short term treated group, respectively. The short-term progesterone treatment was effective to synchronize oestrus in sheep during both breeding and anestrus seasons.Öğe Swiss albino ırkı farelerde sperma kalitesinin belirlenmesi amacıyla hos testi sonuçları ve diğer spermatolojik parametreler arasındaki ilişkinin araştırılması(Selçuk Üniversitesi Sağlık Bilimleri Enstitüsü, 2007) Akman, Orhan; Aksoy, MelihSwiss albino ırkı fare spermatozoonlarında plazma membranının bütünlüğünün belirlenmesi amacıyla klasik supravital boyama yöntemi ile kombine edilmiş modifiye bir hipoozmotik şişme testi (HOS) olan HE (HOS-Eosin - Y) testinin motilite, ölü-canlı ve anormal spermatozoon oranları gibi klasik spermatolojik parametrelerle olan korelasyonu araştırıldı. Çalışmada en az 12 haftalık dişi ve erkek fareler kullanıldı. Çalışma grubuna alınmadan önce erkek fareler in vivo fertilite düzeylerinin kontrol edilmesi amacıyla iki dişi fare ile çiftleştirilerek fertil oldukları ve gebelik sağlayabildikleri doğrulandı. Çalışmanın ilk aşamasında HE testinin yapılması amacıyla uygun ozmotik basınç aralığının belirlenmesi amaçlandı. Erkek fareler servikal dislokasyonla ötenazi yapıldıktan sonra cauda epididimisleri ayrıldı ve sperma sıvı parafin ile örtülmüş Dulbecco's Phosphate Buffered Saline (D-PBS) içerisinde toplandı. Alınan sperma 20, 40, 80, 120, 160, 200, 240, 280, 320, 360 ve 400 mOsm'lük fruktoz solüsyonu içerisinde 30 dk süreyle inkübe edilerek, inkübasyon sonrası eosin ? nigrosin boyası ile boyanıp toplam kıvrık kuyruklu ve boya almamış spermatozoon oranları belirlendi. Bu aşamada 20, 40, 80, 120 ve 160 mOsm lük solüsyonlarda elde edilen şişme cevaplarının (% 52.3 ± 4.7 - 41.5 ± 5.7) istatistiksel olarak benzer olmasına rağmen, 180 ? 400 mOsm gruptan önemli ölçüde yüksek olduğu saptandı. Bu nedenle bu aralıktaki (20 ? 160 mOsm) median grup 80 mOsm olarak belirlendi ve çalışmanın ikinci aşamasında HE testi için bu osmotik basınç eşiği kullanıldı. Çalışmanın ikinci aşamasında ise 80 mOsm'de yapılan HE testi sonrasında kuyruk kıvrılması ve başın boya alması durumu dikkate alınarak spermatozoonlar 4 ayrı tip altında sınıflandırıldı. Buna göre Tip1: Boya almamış-kıvrık kuyruklu; Tip2: Boya almış-kıvrık kuyruklu; Tip3:Boya almamış-düz kuyruklu ve Tip4: Boya almış-düz kuyruklu olarak sınıflandırıldı. Yapılan korelasyon analizi motilite değerleri ile Tip1, Tip2 ve Tip3 spermatozoon oranlarının önemli ölçüde (P<0.05) korelasyon gösterdiğini ortaya koymuştur. Akrozom, baş, orta kısım anomalileri ile HE testi sonuçları arasında korelasyon bulunamazken kuyruk anomalileri ile Tip1 spermatozoon oranı arasında önemli bir negaif korelasyon saptanmıştır (P<0.01). Ölü-canlı spermatozoon oranları ile HE testi arasında herhangi bir korelasyon tespit edilememiştir. Sonuç olarak, farelerde HOS testi için uygun ozmotik aralığın 20 - 160 mOsm olduğu belirlenmiş, bu aralıkta (80 mOsm) uygulanan HE testi sonucunda boya alan ve almayan spermatozoonlarda ayrı ayrı membran bütünlüğü belirlenebilmiş ve HE testi sonuçlarının bazı anormal spermatozoon tipleri (özellikle kuyruk) ve motilite düzeyleri ile korelasyon gösterdiği ancak ölü - canlı spermatozoon oranlarıyla korelasyon göstermediği belirlenmiştir.Öğe Ultrasonographic Examination of the Scrotal Content in the Rabbit(Wiley-Blackwell Publishing, Inc, 2009) Aksoy, Melih; Erdem, Hüseyin; Hatipoğlu, Fatih; Lehimcioğlu, Necdet Cankat; Akman, Orhan; Özkan, KadircanThis study was performed to describe a practical technique for ultrasound examination of the scrotal content of the rabbit. The scrotal content of normal rabbits and those with induced lesions (i.e. needle biopsy of the testis and epididymal ligation) were viewed using a portable scanner connected to a 5 or 7.5 MHz real time, B-mode linear array transducer. The effect of frequency (5 and 7.5 MHz), pad material placed under the testicle (rubber, plastic and carton) and the presence of a water sack between the probe and organ were examined to optimize the technique. The best image quality was obtained using a 5-MHz probe when the testicle was fixed on a rubber pad and covered by a water sack. Testicular parenchyma was imaged as homogeneous and moderately echoic. Caput and cauda epididymis were identified as homogeneous and less echoic compared with the testis parenchyma. Variations in the testicular echotexture that occur secondarily to epididymal ligation and testis biopsy could be screened readily. In conclusion, real-time ultrasonography, performed as described in this study, may provide a valuable tool to screen scrotal contents and to identify certain pathological conditions that affect fertility in the rabbit.
