Usage of oocytes obtained from ovaries aft er long-term cold storage for in vitro embryo production is a promising tool for the protection of wildlife and endangered animal species. Mammalian oocytes ...are susceptible to oxidative stress with regard to the high lipid content of plasma membranes. Melatonin is known as a powerful antioxidant and anti-apoptotic agent due to its ability to eliminate toxic oxygen derivatives and reduce the formation of reactive species. Th is study was performed to verify the optimal environmental conditions for long-term preservation of cat ovaries (Felis domesticus) by adding diff erent concentrations of melatonin (500, 750 and 1000 μM) to the storage medium (0.9% NaCl) as an antioxidant to be preserved at 4°C for 24 h. To determine the eff ect of melatonin on cat oocytes collected from stored ovaries, the anti and proapoptotic gene levels in cumulus oophorus, the in vitro maturation rates, the cell membrane and oocytes viability were evaluated. In all melatonin added groups regardless of whether they are stored in the cold; Pro-apoptotic gene levels (BAX) were determined to be upregulated however, antiapoptotic gene levels (BCL-2) were downregulated in cumulus cells (P<0.05). Th e cell membrane stability and cell viability rates of oocytes began to deteriorate in parallel with the rate of melatonin increase. In parallel with these findings, in vitro maturation rates of oocytes were negatively aff ected as the amount of melatonin increased (P≤0.001). In conclusion the results showed that adding melatonin (500,750 or 1000 μM) to the ovarian transport and storage medium had negative eff ect on in vitro maturation rate, viability and cell membrane structure of cat oocytes.
This study investigated the effect of cysteamine added to an extender at different doses (5 and 10 mM) on the freezing of Saanen buck semen containing samples with seminal plasma or those in which ...the seminal plasma was removed. After the examinations, the ejaculates were pooled. The semen was divided into two equal volumes. The seminal plasma of one group was not removed (Group A), whereas the seminal plasma of the other volume was removed via centrifugation (Group B). Each group was again divided into three equal volumes. Therefore, a total of six groups were created. Subsequent to the equilibration process, diluted semen samples were packaged in 0.25 mL straws, frozen at -110degreesC, and stored at -196degreesC. Frozen semen samples were thawed in a water bath for 30 s at 37degreesC. This procedure was repeated seven times (n=7). In the equilibration stage, 10 mM cysteamine was found to damage the spermatozoa motility regardless of the presence of seminal plasma (p<0.001). After thawing, no statistically significant difference was observed in all the groups. In this study, it was concluded that 10 mM cysteamine damages spermatozoa motility before freezing and the presence of seminal plasma and cysteamine concentrations after thawing had no effect on spermatological properties. Keywords: Antioxidant, buck semen, cysteamine, freezing
The objective of the present study was to examine the effects of two different transport temperature (37°C vs 4°C) and cold storage of ovaries for 24 h on cumulus cell apoptosis and maturation rates ...of cat oocytes in vitro. Ovaries were collected from 15 ovariohysterectomized domestic cats and maintained and transported to the laboratory in phosphate buffer saline at 37°C and 4°C. In order to determine the effects of storing time, some ovaries transported at 4°C were stored at the same temperature for 24 h. Selected cumulus oocyte complexes (COCs) were matured for 48 h at 38°C in four-well petri dishes containing 500 μL of modified oviduct medium (mSOF) under mineral oil in a 5% CO2 incubator with nearly 100% humidified. The morphological features of apoptosis were analysed in the cumulus cells at the beginning of in vitro maturation in both transporting temperature groups and after 24 h of cold stored group. The degree of apoptosis in cumulus cells were measured by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL). The IVM rates of oocytes were determined using Hoechst (33342) staining. Although the apoptotic morphological features were seen rarely and in similar rates in 37 and 4°C transporting groups (19.40 and 21.55%, P>0.001), it was seen more intensely in the 24 h cold stored group (34.80%, P<0.001). The IVM findings were similar (49.77, 44.55%) at 37°C and 4°C groups (P>0.05), and importantly lower at 4°C transporting and 24 h cold stored groups (18.90%, P<0.05). In conclusion, the results of this study suggest that (I) cumulus cells of cat oocytes are partially exposed to apoptosis during transportation at warm or cold temperature, (II) storing of ovaries for 24 h at 4°C causes apoptosis of the cumulus cells at much higher rates and (III) storing of ovaries for 24 h at 4°C affects negatively IVM rate of oocytes.
This is the first report of successful induction of normal estrus and ovulation in breeder bitches with as a low dose as 0.6
μg/kg/day of cabergoline formulation marketed for use in women. Sixty-one ...pure breed bitches from various breeds were used in the study at their already determined periods of anestrus. Twenty-four dogs formed the control group, while 37 bitches were administered with two different doses of cabergoline (recommended dose group,
n
=
10, 5
μg/kg/day and low dose group,
n
=
27, 0.6
μg/kg/day). Induced estrus rates and mean treatment and proestrus durations of dogs in these two dose groups were compared.
At the second phase of the study, the effects of 500
IU human chorionic gonadotropin (hCG) administered on days 1 and 3 of estrus induced by the low dose of cabergoline, on the duration of behavioral estrus, ovulation rates, pregnancy rates and the number of offspring were investigated. For this purpose, the dogs with signs of proestrus (22/27) following the treatment in the low dose group were assigned into two subgroups. Five hundred IU of hCG (Pregnyl, Organon, Turkey) was intramuscularly administered to eight of these dogs low dose (hCG+) group on days 1 and 3 of estrus. The remaining 14 dogs were not treated with hCG low dose (hCG−) group. An aqueous solution of cabergoline (Dostinex, Pharmacia, Italy) was orally administered until 2 day after the onset of proestrus or for a maximum of 42 days. Blood samples were taken daily from all treatment and 11 control bitches during the first five days of behavioral estrus to measure progesterone concentrations. In the recommended dose and low dose groups, estrus was induced between days 8–45 and 4–48 (mean: 23.63
±
14.33 and 24.41
±
14.31 days), in the ratio of 80.0 and 81.5%, respectively (
p
>
0.05). In both dose groups, post-treatment interestrous intervals were significantly shorter than both those of the control group and their own pre-treatment interestrous intervals (
p
<
0.05).
Ovulation rates, pregnancy rates and mean number of offspring delivered by the dogs in the recommended dose, low dose (hCG−), low dose (hCG+) and control groups were found to be similar (
p
>
0.05). However, the mean duration of behavioral estrus of the dogs in the low dose (hCG+) group was found to be significantly longer compared to dogs in all other groups (
p
<
0.05). In both dose groups, no correlation could be found between the anestrus stages and treatment durations (
p
>
0.05).
Shortly, it has been concluded from the study that (1) normal and fertile estrus can be induced more economically in bitches during different stages of anestrus using as a low dose of 0.6
μg/kg of cabergoline formulation marketed for use in women, and that (2) hCG injections on days 1 and 3 of the estrus induced by this method has no positive effects on the ovulation rates, pregnancy rates and the number of offspring per pregnancy.
In the present study, two new short estrus synchronization methods have been developed for lactating dairy cows. The study was completed in three consecutive phases. In experiment (Exp) 1, 32 cows, ...that were not detected in estrus since calving between the 50th and 84th post-partum days, were treated with PGF2α (PGF,
d-cloprostenol, 0.150
mg), estradiol propionate (EP, 2
mg) and GnRH (lecirelina, 50
μg) at 24
h intervals, respectively, and timed artificial insemination (TAI) was performed 48
h after PGF. Different from Exp 1, EP and GnRH were given at 48 and 60
h, respectively after PGF in Exp 2 (
n
=
20), instead of 24 and 48
h. Ovulations were investigated by ultrasound for 7 days starting from the day of PGF treatment, and ovulation rates were compared with the ones obtained in Exp 1. In Exp 3, cows were given the same treatments as Exp 2, but treatments started at certain estrus stages. Cows detected in estrus and with a confirmed ovulation (
n
=
27) after the second PGF given 11 days apart were assigned to three treatment groups. Treatment was initiated at Day 3 (group metestrus,
n
=
9), Day 12 (group diestrus,
n
=
9) and Day 18 (group proestrus,
n
=
9) after ovulation. All cows included in Exp 3 were TAI between 16 and 20
h after GnRH treatment. In Exp 2 and 3, blood samples were obtained once every 2 days, starting from Day 0 to the 10th day after GnRH injection, and once every 4 days between the 10th and the 22nd days after GnRH to examine post-treatment luteal development. During the study, animals exhibiting natural estrus were inseminated and served as controls (
n
=
85). The rate of estrus was found to be significantly higher in cows with an active corpus luteum (CL) at the start of Exp 1 (72.7% vs. 30.0%,
P
<
0.05) and the pregnancy rate tended to be higher than cows without an active CL (40.9% vs. 10.0%,
P
=
0.08). Compared to those in Exp 1, cows in Exp 2 had higher rates of synchronized ovulation (94.1% vs. 59.1%,
P
=
0.013). In Exp 3, estrus (
P
<
0.001) and pregnancy rates (
P
=
0.01) were found to be significantly higher in cows in the proestrus group than in those in the metestrus group. Comparable pregnancy rates were obtained from the first and second inseminations in Exp 1 and 3 with results from those inseminated at natural estrus (
P
>
0.05).
It was concluded from the study that the treatment in Exp 1 and 3 could result in comparable pregnancy rates after timed AI of lactating dairy cows at random stages of the estrus cycle relating to those inseminated at natural estrus, but the stage of the estrus cycle can have significant effects on pregnancy rates.
The primary aim of the study was to investigate whether iodixanol and trehalose would have a synergic effect on the cryosurvival of electroejaculated ram semen. Tris‐based diluter was used to prepare ...9 different extenders by the addition of iodixanol or trehalose alone or varying combinations of these substances. Diluters were prepared as follows: Tris (control), Io5 (5% iodixanol), Tr25 (25 mmol/L trehalose), Tr50 (50 mmol/L trehalose), Tr50 + Io1.25 (50 mmol/L trehalose and 1.25% iodixanol), Tr50 + Io2.5 (50 mmol/L trehalose and 2.5% iodixanol), Tr50 + Io5 (50 mmol/L trehalose and 5% iodixanol), Tr25 + Io5 (25 mmol/L trehalose and 5% iodixanol) and Tr12.5 + Io5 (12.5 mmol/L trehalose and 5% iodixanol). Supplementation of the freezing extender with trehalose or iodixanol alone supported the protection of both morphological and functional integrity of ram spermatozoa and total motility at 1 and 4 hr post‐thawing respectively. However, beyond these positive effects, the combination of trehalose (25 mmol/L) and iodixanol (5%) significantly increased post‐thaw sperm longevity and motion properties at the end of 4‐hr incubation. The results of the study clearly showed that there was positive synergic effect of iodixanol and trehalose on cryosurvival of ram semen.
Whose City is That? shows that Istanbul is produced not only by strong and systematic efforts, corporate influences and/or marketing activities, but also by individual contributions and coincidences. ...As such, the primary purpose of this book is to find the answer of to whom Istanbul does belong, presenting the reader with the richness of human experience and the practice of everyday life. The chapters in this book are therefore focused on the physical and economic dimensions, as well as the i.
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