RESUMEN
Maternal diabetes-mediated fetal programming is widely discussed, however, it is important to define the extent to which intrauterine hyperglycemia interferes with the health of female pups, along with determining whether these changes can be perpetuated across generations. This study aimed to evaluate the effects of maternal diabetes on fetal programming and the repercussions on the metabolism of pregnant and nonpregnant female pups. Diabetes status was induced (diabetic group-D) using streptozotocin (a beta cell cytotoxic drug) on the fifth postnatal day of female rats, while controls received a citrate buffer (Control-C). In adulthood, the rats were mated to obtain their female pups. At 90 days of age, half of the female pups were mated (preg) and the other half continued virgin (Npreg). Furthermore, they were distributed into four groups: OC/Npreg and OC/preg-female pups from control mothers; OD/Npreg and OD/preg-female pups from diabetic mothers. At 115 days of life and/or 17 days of pregnancy, the oral glucose tolerance test (OGTT) was performed with blood collection for insulin measurement. At 120 days of life and/or 21 days of pregnancy, the rats were anesthetized and euthanized to determine their blood oxidative stress status. The OD/Npreg group showed glucose intolerance during OGTT (p < 0.0001), while the OD/preg group showed increased insulin secretion during OGTT (p < 0.0001) and insulin resistance (IR; p = 0.0027). An increase in homeostatic model assessment ß was shown in the pregnant groups, regardless of maternal diabetes (p < 0.0001). The OD/preg group presented increased thiobarbituric acid reactive substances (p < 0.0001) and -SH levels (p = 0.0005) and decreased superoxide dismutase activity (p = 0.0063). Additionally, small fetuses for gestational age (p < 0.0001) were found in these rats. In conclusion, exposure to maternal hyperglycemia compromises the glycemic metabolism of female pups before and during pregnancy and causes oxidative stress, IR, and impaired fetal growth during pregnancy.
Asunto(s)
Diabetes Mellitus , Hiperglucemia , Insulinas , Ratas , Embarazo , Femenino , Animales , Estreptozocina , Sustancias Reactivas al Ácido Tiobarbitúrico , Glucemia/metabolismo , Hiperglucemia/metabolismo , Superóxido Dismutasa , CitratosRESUMEN
Reactive oxygen species (ROS) can be generated in mammalian cells via both enzymatic and non-enzymatic mechanisms. In sperm cells, while ROS may function as signalling molecules for some physiological pathways, the oxidative stress arising from the ubiquitous production of these compounds has been implicated in the pathogenesis of male infertility. In vitro studies have undoubtedly shown that spermatozoa are indeed susceptible to free radicals. However, many reports correlating ROS with sperm function impairment are based on an oxidative stress scenario created in vitro, lacking a more concrete observation of the real capacity of sperm in the production of ROS. Furthermore, sample contamination by leukocytes and the drawbacks of many dyes and techniques used to measure ROS also greatly impact the reliability of most studies in this field. Therefore, in addition to a careful scrutiny of the data already available, many aspects of the relationship between ROS and sperm physiopathology are still in need of further controlled and solid experiments before any definitive conclusions are drawn.
RESUMEN
The aim of this study was to compare the efficiency of the intravaginal (IVAI) vs. intrauterine artificial insemination (IUAI) using frozen-thawed sperm in the domestic cat. Semen was collected from two tom cats using an artificial vagina and samples were assessed for motility (computer-assisted sperm analysis (CASA)), sperm morphology and plasma membrane integrity. After dilution with TRIS/OEP/YOLK (4% of glycerol), sperm samples were loaded into 0.25 mL straws (25 x 10(6)motile sperm/straw), incubated at 5 degrees C for 20 min and cryopreserved over liquid nitrogen (LN(2)) vapor for 15 min and then immersed in LN(2). For each AI, four straws from the same male were thawed (12s at 46 degrees C) and centrifuged at 250 x g for 8 min to pellet the sperm. The supernatant was discarded and sperm pellet resuspended with the remaining liquid, approximately 100 microL, and analyzed as described above. Queens were treated with a single im injection of 100 IU eCG to induce ovarian follicular development. Final oocyte maturation and ovulation was induced with 100 IU hCG given im at 82-84 h after eCG administration. Thirty hours after hCG administration, females were inseminated either intrauterine (n=8 queens) or intravaginally (n=8 queens), using thawed sperm from a single male. Although a pronounced decrease in sperm motility, acrosome and plasma membrane integrity was observed in sperm samples from both cats, a pregnancy rate of 75% was achieved when using the intrauterine AI method compared with 0% pregnancy when inseminated intravaginally.