Ovariektomize edilen sıçanlarda pterin -6- karboksilik asit ve LH-RH'un pinealositler ile hipofizde gonadotrop ve mammatrop hücrelerin ultrastrüktürüne etkileri

Abstract

Bu çalışmada ovariektomi yapılmış sıçanlarda pterin-6-karboksilik asit ve LH-RH'un epifizin pinealositleri ile hipofizde bulunan gonadotrop ve mammatrop hücrelerin ultrastrüktürleri üzerine olan akut etkileri araştırılmıştır. Çalışmada 10 günlük, ovariektomi yapılmış 12 ergin sıçan kullanılmıştır. Hayvanlar 4'er bireylik 3 gruba ayrılarak; 1. gruba 5 mg/kg. pterin-6-karboksilik asit, 2. gruba 0.2 ml/kg. LH-RH verilmiştir. 3. gruba yalnızca çözücü sıvı enjeksiyonu yapılarak kontrol grubu oluşturulmuştur. Enjeksiyondan 1 saat sonra dekapitasyon ile öldürülen hayvanlardan mikroskobik incelemeler için alınan dokular glutaraldehit ve OsO4 te fikse edildikten sonra vestopale gömüldüler. LKB ultrottomu ile alınan ince kesitler uranil asetat ve kurşun sitrat ile kontrastlandıktan sonra JEOL 100-C transmission elektron mikroskobunda incelendiler. Yapılan gözlemler sonucunda pterin-6-karboksilik asitin ovariektomi yapılmış sıçanlarda pinealositler ile gonadotrop hücrelerin aktivitelerini artırırken, mammatrop hücreleri de aktive ettiği gösterilmiştir. LH-RH alan sıçanlarda ise pinealositlerde ve gonadotrop hücrelerde aktivitenin arttığı, ancak mammatrop hücrelerde belirgin bir değişiklik oluşturmadığı gözlenmiştir.

Effects of pterin-6-carboxylic acid (P6CA) and Luteinizing hormon Releasing hormon on ultrastructure of pinealocytes and gonadotrop and mammotrop cells of hypophsis in oariectomized rats: In this study, the acute effects of LH-RH and P6CA on the ultrastructures of pinealocytes of epiphsis, gonadotrop and mammotrop cells of hypopysis of previously ovariectomized rats were investigated. A sum of 12 adult rats, that were subjected to bilateral ovaiectomy, ten days prior to start the applications were used. Animals were divided into tree groups, each of which was consisted four rats. First group received P6CA (5 microgram per kg of body weight), while the second group rats were treated with LH-RH (0.2 ml per kg of body weight of rats), and the last group was given only solvent, in equal volume and served as the negative controls. Tissue samples were taken into glutaraldehyde and Osmium tetroxide fixative solutions for comparative histological examinations from all animals that were killed by deca pitation. Performed exactly one hour after injections of test substances. Following the fixation, tissue samples were embedded into Vestopal to prepare thin sections by LKB ultratom. Tissues were contrasted with Uranyl acetate and lead citrate before reading under JEOL 100-C Transmission Electron Mic roscope. The results showed that, P6CA increased the activity of pinealocytes and gonadotrop hormon secreting cells and activated the mammot rop hormon secreting cells in hypophyseal gland in ovariectomized rats. How ever, LH-RH was not active as P6CA; and only slightly stimulated the activity of pinealoctes and gonadotrop secreting cell, while no appreciable change was observed in mammotrop hormon secreting cells as the result of treatment.