Browsing by Author "Yildiz, C"

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Effects of a Gnrh Agonist on Oocyte Number and Maturation in Mice Superovulated With Ecg and Hcg
(Elsevier Science inc, 2004) Kanter, M; Yildiz, C; Meral, I; Koc, A; Tasal, I
The objective was to investigate the effects of a gonadotropin-releasing hormone agonist (GnRH) on ovulation rate and the number and maturation of oocytes in mice superovulated with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). Thirty 3-month-old BALB/C female mice (weight: 25-30 g) were assigned to three experimental groups: control, superovulated, and superovulated with GnRH pretreatment (n = 10 per group). Control mice received an i.p. injection of 0.1 ml physiological saline solution. Superovulation was induced with 5 IU eCG (i.p.) and 5 IU hCG 48 It later. Mice in the superovulated with GnRH pretreatment group were given GnRH (20 mg/kg Fertirelin, i.m.), 24 h before superovulation. Thirteen hours after hCG administration, mice were sacrificed by cervical dislocation and blood samples were collected to determine serum progesterone concentration (by radioimmunoassay). Ovaries and oviducts were also harvested to enumerate corpora lutea and cumulus-enclosed oocytes. Progesterone concentrations were not significantly different among groups. The oocyte number and the maturation, ovulation rate, and the number of corpora lutea were higher in GnRH-treated mice than both controls and superovulated mice. In conclusion, GnRH given 24 h before superovulation with eCG-hCG increased the number and maturation of oocytes and the rate of ovulation in mice. (C) 2003 Elsevier Inc. All rights reserved.
Influence of Melatonin Implantation on Sperm Quality, Biochemical Composition of the Seminal Plasma and Plasma Testosterone Levels in Rams
(Ecole Nationale veterinaire Toulouse, 2000) Kaya, A; Baspinar, N; Yildiz, C; Kurtoglu, F; Ataman, MB; Haliloglu, S
Influence of the melatonin implantation on sperm quality, plasma testosterone levels and biochemical composition of the seminal plasma was evaluated in rams in the breeding and non-breeding season. Melatonin administration during the non-breeding season improved progressive motility and morphologically normal sperm rates. The mean plasma testosterone level was significantly higher in melatonin treated animals compared to untreated ones. Fructose, sodium, calcium, magnesium levels, and aspartate aminotransferase and lactate dehydrogenase activity in the seminal plasma were similar in melatonin treated and control rams. In contrast, melatonin administration during the breeding season did not enhance spermatologic parameters and plasma testosterone levels. Biochemical composition of the seminal plasma was also comparable in melatonin treated and untreated control groups. In conclusion, melatonin administration during the breeding season did not influence sperm quality, plasma testosterone levels and biochemical parameters evaluated in this study.