Search results for "Ovariectomized rat"
showing 10 items of 24 documents
Mitochondria from females exhibit higher antioxidant gene expression and lower oxidative damage than males
2003
We have investigated the differential mitochondrial oxidative stress between males and females to understand the molecular mechanisms enabling females to live longer than males. Mitochondria are a major source of free radicals in cells. Those from female rats generate half the amount of peroxides than those of males. This does not occur in ovariectomized animals. Estrogen replacement therapy prevents the effect of ovariectomy. Mitochondria from females have higher levels of reduced glutathione than those from males. Those from ovariectomized rats have similar levels to males, and estrogen therapy prevents the fall in glutathione levels that occurs in ovariectomized animals. Oxidative damage…
Mitochondrial damage in aging and apoptosis.
2002
: Mitochondria are essential to cellular aging, and free radical production by mitochondria is increased with aging. The rate of oxidant production by mitochondria correlates inversely with maximal life span of species. In many species, females live longer than males. We report that mitochondrial oxidant production by females is significantly lower than that of males. However, mitochondria from ovariectomized females have a similar oxidant production as those of males. Thus, gender difference in life span can be explained, at least in part, by different oxidant generation by mitochondria. Administration of antioxidants, such as vitamins C and E, or a Ginkgo biloba extract, protects against …
Effect of low-calcium diet and grind diet on bone turnover of ovariectomized female rats
2011
Made available in DSpace on 2013-08-12T19:12:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-01 Made available in DSpace on 2013-09-30T18:34:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:04:37Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T14:04:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Objective: The variety of methodologies used to investigate ovariectomized female rats shows different results, which makes a clinical application of these results difficult. The purpose of t…
Gathering of aging and estrogen withdrawal in vascular dysfunction of senescent accelerated mice.
2010
The aim of this work was to characterize a mouse model of experimental menopause and cardiovascular aging that closely reflects menopause in women. Senescence accelerated mouse (SAM)-Resistant type 1 (SAMR1, n=30) and SAM-Prone type 8 (SAMP8, n=30) were separated at 5months of age into three groups: 1) sham-operated (Sham); 2) ovariectomized (Ovx); and 3) ovariectomized chronically-treated with estrogen (Ovx+E2). Contractile responses to KCl (60mM) and thromboxane A(2) were greater in aorta from SAMP8 mice compared with SAMR1 in all groups. Neither ovariectomy nor estrogen replacement modified the contractile responses from SAMR1 mice. Conversely, in Ovx SAMP8 the increased maximal contract…
The non-aromatizable androgen dihydrotestosterone (DHT) facilitates sexual behavior in ovariectomized female rats primed with estradiol
2020
Abstract It is still unclear whether Testosterone (T) increases sexual desire through a stimulation of the androgen receptor in relevant brain regions or through its conversion to estrogens. The aim of this study was to clarify the mechanisms of T facilitation of female sexual desire by assessing the effect of a non-aromatizable androgen (Dihydrotestosterone, DHT) in a validated animal model. Ovariectomized (OVX) Long-Evans rats were treated with oil (O) + O, 10 mcg Estradiol Benzoate (EB) + O, 10 mcg EB + 500 mcg Progesterone (P), O + 500 mcg DHT or 10 mcg EB + 500 mcg DHT (n = 12 per group). EB was administered 48 h, while P and DHT 4 h, prior to 4 sexual behavioral testing sessions in bi…
Increased LH and FSH release from the anterior pituitary of ovariectomized rat, in vivo, by copper-, nickel-, and zinc-LHRH complexes.
1992
Abstract The effect of Cu 2+ , Ni 2+ , Zn 2+ and their complexes with LHRH on the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) was estimated in in vivo experiments with the use of the method proposed by Ramirez and McCann. Ovariectomized, estradiol, and progesterone pretreated rats were injected intraveneously either with LHRH alone, a metal ion alone, a mixture of metal and hormone, or a metal-LHRH complex. A metal alone or a mixture of it with LHRH did not affect gonadotropin release at all or no more than LHRH alone. However, the complex of Cu 2+ with LHRH brought about a high release of LH and even higher release of FSH. This indicates that copper complex i…
Physical exercise neuroprotects ovariectomized 3xTg-AD mice through BDNF mechanisms.
2014
Postmenopausal women may be more vulnerable to cognitive loss and Alzheimer's disease (AD) than premenopausal women because of their deficiency in estrogens, in addition to their usually older age. Aerobic physical exercise has been proposed as a therapeutic approach for maintaining health and well-being in postmenopausal women, and for improving brain health and plasticity in populations at high risk for AD. To study the neuroprotective mechanisms of physical exercise in a postmenopausal animal model, we submitted previously ovariectomized, six-month old non-transgenic and 3xTg-AD mice to three months of voluntary exercise in a running wheel. At nine months of age, we observed lower grip s…
Impact of estrogens on atherosclerosis and bone in the apolipoprotein E-deficient mouse model.
2014
Objective The common inflammatory pathophysiology has nourished the hypothesis of a relationship between osteoporosis and cardiovascular disease. Estrogens are key agents in the modulation of both processes. We investigated whether induction of atherosclerosis affects bone and whether estrogens modulate both processes. Methods Female apolipoprotein E-deficient mice (a well-established model of atherogenesis) were ovariectomized or falsely operated and fed either standard diet or high-fat diet (HFD). Six animals were included in each of the four groups. To clarify mechanisms, we treated preosteoblastic MC3T3-E1 cells with mouse serum. Results Physiological levels of estrogens in falsely oper…
Radiodensitometric study for evaluation of bone mineral density around dental implants after zoledronic acid treatment in ovariectomized rats
2017
Background The purpose of this study was to evaluate the effects of intravenous zoledronic acid applied systemically on osseointegration of dental implants and the surrounding bone mineral density (BMD) in the ovariectomized rats. Material and Methods 36 rats were divided into three groups: control (CTRL), ovariectomy (OVX), and ovariectomy-zoledronic acid (OVX/ZOL). The rats in the CTRL group underwent sham surgery, while rats in OVX and OVX / ZOL group underwent ovariectomy. After 12 weeks, rats from OVX / ZOL were injected with 0.04 mg/kg ZOL intravenously once a week for 6 weeks. The rats from CTRL and OVX groups were injected with 0.9% NaCl. Implants were placed in the left tibia. Afte…
Physical Activity Differentially Affects the Cecal Microbiota of Ovariectomized Female Rats Selectively Bred for High and Low Aerobic Capacity
2015
The gut microbiota is considered a relevant factor in obesity and associated metabolic diseases, for which postmenopausal women are particularly at risk. Increasing physical activity has been recognized as an efficacious approach to prevent or treat obesity, yet the impact of physical activity on the microbiota remains under-investigated. We examined the impacts of voluntary exercise on host metabolism and gut microbiota in ovariectomized (OVX) high capacity (HCR) and low capacity running (LCR) rats. HCR and LCR rats (age = 27 wk) were OVX and fed a high-fat diet (45% kcal fat) ad libitum and housed in cages equipped with (exercise, EX) or without (sedentary, SED) running wheels for 11 wk (…