The age-related decline in fat-free mass is accelerated in women after menopause. The role of ovarian hormone deficiency in the regulation of fat-free mass, however, has not been clearly defined. To address this question, we examined the effect of ovarian hormone suppression on whole body protein metabolism. Whole body protein breakdown, oxidation, and synthesis were measured using [(13)C]leuci...

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...

The aging kidney exhibits a progressive decline in glomerular filtration rate, accompanied by inflammatory and oxidative damage. We hypothesized that accelerated, age-related progression of renal injury is ovarian hormones-dependant. To address this we used an established model of developmentally programmed accelerated renal aging in the rat, superimposed by ovariectomy to assess interactions b...

An early full-term pregnancy significantly reduces the risk of getting breast cancer in women. In animals, this protection can be mimicked by a short-term exposure to physiologic doses of estrogen plus progesterone. Sensitization of p53 and up-regulation of transforming growth factor beta are believed to be important aspects of the mechanism by which protection is imparted. Little is known, how...

Differences in the aggregation and release of growth factors including matrix metalloproteinases (MMPs) after loss of ovarian hormones could contribute to an exaggerated response to injury in arteries of ovariectomized animals. Therefore, experiments were designed to compare aggregation, dense granular ATP release, expression of MMPs (MMP-2, MMP-9, and MMP-14) and tissue inhibitors of metallopr...

Mouihate, A., X. Chen, and Q. J. Pittman. Interleukin-1b fever in rats: gender difference and estrous cycle influence. Am. J. Physiol. 275 (Regulatory Integrative Comp. Physiol. 44): R1450–R1454, 1998.—Evidence exists to support the concept of sex difference in immune system activation by pyrogenic cytokines. In this study, fever development was monitored to analyze the effect of peripheral adm...

It is recognised that ovarian factors, including steroid and protein hormones, are critical in the feedback regulation of pituitary gonadotropins; however, their individual contributions are less defined. The aim of this study was to explore the reciprocal relationships between ovarian and pituitary hormones across the normal ovulatory menstrual cycle as women age. FSH, LH, oestradiol, progeste...

Obesity in women is increased by the loss of circulating estrogen after menopause. Shift work, which disrupts circadian rhythms, also increases the risk for obesity. It is not known whether ovarian hormones interact with the circadian system to protect females from obesity. During high-fat feeding, male C57BL/6J mice develop profound obesity and disruption of daily rhythms. Since C57BL/6J femal...

When considering why women are more prone to money pathologies than men the influence of ovarian hormones cannot be ruled out. The phases of the menstrual cycle are known to have a range of behavioural, psychological and physical correlates. It is well documented, for example, that women are more rational and controlled post-ovulation, but experience a rise in impulsive behaviour, anxiety and i...

Acute exposure to morphine after a traumatic event reduces trauma related symptoms in humans and conditioned fear expression in male rats. We aimed to determine whether acute administration of morphine alters consolidation of fear learning and extinction. Male and female rats in proestrus and metaestrus (high and low ovarian hormones respectively) underwent fear conditioning and received saline...