1,721,017 research outputs found
CYSTIC OVARIAN FOLLICLES AND THYROID ACTIVITY IN THE DAIRY COW
No full textThyroid activity affects the functionality of the reproductive axis and thyroid dysfunction has been associated with ovarian hyperstimulation syndrome and polycystic ovarian syndrome, in human medicine. This study investigates serum17- < beta> estradiol, progesterone, thyrotropic and thyroid hormone levels, in cyclic dairy cows on heat (Group H) and in dairy cows with ovarian follicular cysts (Group FC). Both 17- < beta> estradiol and progesterone serum concentrations were statistically higher in cystic than in cyclic cows (estradiol: 8.51 ± 1.91 vs 6.32 ± 1 pg/mL) (progesterone: 0.49 ± 0.17 vs 0.13 ± 0.03 ng/mL), whereas TSH and fT4 serum concentrations were statistically lower in cows with cystic ovarian follicles (COF), compared to cyclic ones (TSH: 2.48 ± 1.31 vs 3.56 ± 1.03 ng/mL) (fT4: 5,86 ± 1.69 vs 8.63 ± 1.08). fT3 serum levels were similar, in both cystic and cyclic subjects (2.94 ± 0.65 vs 3.02 ± 0.9, respectively). Standing on these results, a look to the functioning of thyrotropic axis should be given in dairy cows with COF, just like it is routinely performed in human gynaecology, in case of ovarian diseases. If severe hypothyroidism should be found, a hormone replacement therapy could be attempted in cystic cows refractory to “ordinary” therapies
Alpha-fetoprotein in animal reproduction.
No full textAlpha-fetoprotein (AFP) is a serum glycoprotein with structural and physico-chemical properties similar to albumin. However, the exact physiological functions of AFP remain unknown; those known to date include markers to pathological conditions including neoplastic and non-neoplastic diseases, antioxidant effects, growth regulator in different cells and in cancer, immune response modulator, and carrier for fatty acids and oestrogens. This review aimed to present an overview of the different functions of AFP, particularly its role in the sexual differentiation of the hypothalamus, because its ability to bind oestrogens prevents their passage to the brain, where they inhibit the surge centre development. AFP and anti-Mullerian hormone are known to be involved in the development of freemartins, or genetically female foetuses masculinised in the presence of a male co-twin
Oxidative state in the estrus cycle of the buffaloes: a preliminary study
Full text linkThe oxidative status, the relationship between oxidizing agents (free radicals) and antioxidant system, is able to influence the correct performance of the estrus cycle. The aim of the experimentation was to define a first range of physiological values of reactive oxygen species (ROS) and the biological antioxidant potential (BAP), found during the phases of the buffalo estrus cycle. In this study, blood samples were taken from 30 buffaloes in various phases of the estrus cycle (estrus, diestrus, anestrus), on which serum determinations, by a photometer, of BAP and ROS have been carried out. The highest ROS values were detected during estrus and this is due to the primary role they play in determining ovulation. The highest levels of BAP have been found in diestrus, when they perform protective action against oxidative damage in the ovaries and uterus
Impact of single administration of hCG on free thyroid hormone levels in mares at oestrus.
No full textCisti follicolari nella bovina: somministrazione di lecirelina per via epidurale e valutazione della renina e della vascolarizzazione ovarico.
No full textEvaluation of blood and milk oxidative status during early postpartum of dairy cows.
No full textIn dairy cows, the intensity of metabolic activity, associated with the negative energy balance (NEBAL), is responsible for an increased production of reactive oxygen species (ROS) and, subsequently, for the development of the condition of oxidative stress, which may overwhelm the antioxidant potential of the bovine maternal organism, making it prone to the development of many puerperal dysfunctions, as well as to an alteration of colostrum and milk quality. Given these premises, the aims of this study are to evaluate serum and milk concentrations of ROS and lipoperoxides, vitamins A and E, on the 10th, 12th, 14th and 16th day postpartum of dairy cows, a particularly critical period during which the NEBAL reaches its nadir, and to compare the trends of these parameters in two different bovine breeds. The study was performed in pluriparous Italian Friesian and Brown dairy cows. On the 10th day postpartum, all cows underwent a clinical examination to exclude the presence of alterations; furthermore, on the same day, a milk sample was collected from each cow, in order to perform the somatic cell count (SCC; (CE) N. 853/2004) and to establish which of them had an SCC ≤400 000/ml or >400 000/ml. In this study, among the 110 cows that were initially selected, the evaluation of these parameters allowed the inclusion of 80 animals, which were divided into four groups of 20 subjects each: Group F and F1: Italian Friesian healthy cows, with SCC ≤400 000/ml and >400 000/ml, respectively; Group B and B1: Italian Brown healthy cows, with SCC ≤400 000/ml and >400 000/ml, respectively. On the 10th, 12th, 14th and 16th day postpartum, peripheral blood and milk samples were collected. The results obtained show that in group B1 there were higher concentrations of ROS and milk antioxidants compared with Friesian group cows. This datum let us suppose that even in the presence of higher ROS concentrations the antioxidant status found in group B1 seems to be able to counteract the oxidative damage, which is more likely to develop in these cows
Oxidative Stress During Pregnancy In The Sheep.
Full text linkDuring physiological pregnancy, all tissues and, mostly, placenta and foetus require high amounts of oxygen. Reactive oxygen species (ROS), generated both by mother and foetus, are implicated in foetal growth because they promote replication, differentiation and maturation of cells and organs. Nevertheless, ROS excess, if not properly counterbalanced, may lead to an alteration in cell constituents, with harmful effects both on mother and foetus.ROS exert a biphasic effect because adequate ROS concentration is essential for embryo development, implant, foetal defence against uterine infections, steroidogenesis, pregnancy maintainance and partum. On the other hand, an uncontrolled ROS generation, beyond physiological antioxidant defences, may lead to embryo resorption, placental degeneration with subsequent alteration in maternal-foetal exchanges, delay in foetal growth, pregnancy interruption, stillbirths. This review investigates the mechanisms underlying ROS generation and effects, throughout physiological and pathological pregnancy in sheep, with a look to antioxidants and their importance in such a critical phase of the reproductive cycle of the sheep
Evaluation of serum concentrations of interleukin (IL)-4, IL-10, and IL-12 during pregnancy in bitches
No full textComplex cytokine networks play an important role in a wide range of pregnancy-related
processes. During physiological pregnancy, the balance of T helper lymphocytes Th1 and
Th2 is strongly shifted toward Th2, which has a protective role in the feto–maternal
interaction. The aim of the present study is to establish the serum concentrations, ranges,
and trends of anti-inflammatory interleukin (IL)-4 and IL-10, and inflammatory IL-12A,
during three phases of gestation in the bitch (20–30, 31–40, and 41–57 days of gestation).
Our results indicate that, in early gestation, IL-4 and -10 serum concentrations are
elevated and might depend on progesterone that could act as a potent inhibitor of Th1
responses inducing, conversely, the production of Th2-type cytokines (i.e., IL-10 and IL-4).
On the other hand, between 30 and 40 days of gestation, the concentrations of the antiinflammatory
ILs decrease probably because of high concentrations of prolactin, which
is endowed with immunostimulatory properties on different immune cell types. In the
third phase of gestation (41–57 days), an increase in IL-10 occurs, which might depend on
high levels of 17b-estradiol that, during pregnancy, interfere with the ability of dendritic
cells to stimulate T lymphocytes, acting as an anti-inflammatory factor. Conversely, the low
and persistent concentrations of inflammatory IL-12A, throughout pregnancy, compared
with anti-inflammatory ILs, might depend on the characteristic cytokine products of Thl
and Th2 cells that are known to be mutually inhibitory. The monitoring of immunological
status via the levels of cytokines during pregnancy in the bitch, could represent a diagnostic
tool to predict and/or prevent pregnancy abnormality, as demonstrated in wome
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