BACKGROUND A prospective randomized study was used to compare surgery times for laparoscopic ovariectomy and salpingectomy in female African lion (Panthera leo) (n = 14) and cheetah (Acinonyx jubatus) (n = 20) and to compare the use of a multiple portal access system (MPAS) and single portal access system (SPAS) between groups. Two different portal techniques were used, namely MPAS (three separ...

BACKGROUND Learning and memory are the most intensively studied subjects in neuroscience. Two sites of mammalian brain which are important in learning and memory are CA1 region of hippocampus and Purkinje cell layer of cerebellum. So, the aim of present investigation was to study of the effect of ovariectomy and passive avoidance learning on NR1 subunit of N-methyl-D-aspartate (NMDA) receptor d...

In vivo studies have shown T cells to be central to the mechanism by which estrogen deficiency induces bone loss, but the mechanism involved remains, in part, undefined. In vitro, T cells from ovariectomized mice produce increased amounts of tumor necrosis factor (TNF), which augments receptor activator of NF-kappa B ligand (RANKL)-induced osteoclastogenesis. However, both the mechanism and the...

After brain injury, astrocytes acquire a reactive phenotype characterized by a series of morphological and molecular modifications, including the expression of the cytoskeletal protein vimentin. Previous studies have shown that estradiol down-regulates reactive astrogliosis. In this study we assessed whether raloxifene and tamoxifen, two selective estrogen receptor modulators, have effects simi...

OBJECTIVE To evaluate surgical techniques, perioperative complications and outcome of laparoscopic surgery for unilateral and bilateral ovariectomy in mares. STUDY DESIGN Retrospective multicenter case series. ANIMALS Mares (n = 157). METHODS Indications for surgery were neutering, fertility problems, elimination of hormone-related abnormal behavior, ovarian tumors as well as nonregressiv...

OBJECTIVE In malnutrition both the GH-IGF and reproductive axes are greatly affected. Because the actions of IGF and sex steroids are inter-dependent in many tissues, we have examined how ovariectomy modulates the response of the systemic IGF system to undernutrition. DESIGN AND METHODS Peripubertal (30 days of age) female rats were either sham operated or ovariectomized. Five days later half...

Decline of estrogen during menopause has been associated with numerous significant changes that have been linked to many pathophysiological complications. In addition, ovarian hormone deficiency increases the production of reactive oxygen radicals which could result in oxidative stress and cell damage. While estrogen therapy is often considered to overcome the behavioral and physiological short...

OBJECTIVE Estrogen replacement therapy (ERT) ameliorates symptoms in postmenopausal women with syndrome X. We hypothesized that estrogen deprivation and replacement may modulate coronary expressions of angiogenic molecules, thereby modifying the coronary capillary network in perimenopausal women. METHODS AND RESULTS Middle-aged (40-week-old) female rats were subjected to sham surgery, ovariec...

Sexual size dimorphism (SSD) reflects sex-specific solutions to the allocation of energy among growth, reproduction and survival; however, the proximate mechanisms behind these solutions are still poorly known even in vertebrates. In squamates, sexual differences in body size used to be attributed to direct energy allocation to energetically demanding processes, largely to reproduction. In addi...

OBJECTIVE Technically primates and dogs represent ideal models to investigate diseases characterized by abnormal intracortical remodeling. High expenses and ethical issues, however, restrict the use of those animals in research. Rodent models have been used as alternatives instead, but their value is limited, if none, because these animals lack intracortical bone remodeling. This study aimed at...