Neuroendocrine Mechanisms By Which Leptin Regulates Reproduction
Funder
National Health and Medical Research Council
Funding Amount
$447,750.00
Summary
The reproductive system is sensitive to alterations in body weight. In particular, low body weight causes the reproductive system to cease functioning. This is because the brain 'senses' metabolic status and responds by ceasing to secrete the brain hormone that drives the reproductive process. This hormone is gonadotropin releasing hormone that acts on the pituitary gland to control the release of gonadotropins. These, in turn, act on the gonads. How the brain perceives metabolic status is not k ....The reproductive system is sensitive to alterations in body weight. In particular, low body weight causes the reproductive system to cease functioning. This is because the brain 'senses' metabolic status and responds by ceasing to secrete the brain hormone that drives the reproductive process. This hormone is gonadotropin releasing hormone that acts on the pituitary gland to control the release of gonadotropins. These, in turn, act on the gonads. How the brain perceives metabolic status is not known. Leptin is a hormone that is produced by fat and acts on the brain. This appears to be one of the means by which the reproductive system is regulated. Leptin also regulates food intake and other brain processes. Leptin acts on specific cell types in the brain. Some of these may have dual function to regulated appetite as well as reproduction. The present proposal is for work to determine mechanisms within the brain that are altered by leptin. We will also determine which specific mechanisms relate to the regulation of gonadotropin releasing hormone. The work will provide information on how putative appetite regulators might affect the reproductive axis. Such work will provide a platform for design of pharmaceutical means to manipulate the reproductive axis and will impact on the design of drugs that regulate obesity. It is possible that drugs that developed to control obesity may affect the reproductive axis and the project will identify these.Read moreRead less
Isolation And Function Of Human Oogenesis Genes Regulating Meiosis, Recruitment, Growth And Maturation Of The Oocyte.
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
Reproductive medicine has progressed very rapidly with the development of in vitro fertilization (IVF) and has delivered the opportunity for a broad group of infertile couples to form their own families. As a consequence, treatment of infertility by major surgery and artificial insemination with donor sperm have declined and there is an increasing interest in the use of IVF to diagnose severe genetic disease in embryos of families at risk. However, little is known about the underlying processes ....Reproductive medicine has progressed very rapidly with the development of in vitro fertilization (IVF) and has delivered the opportunity for a broad group of infertile couples to form their own families. As a consequence, treatment of infertility by major surgery and artificial insemination with donor sperm have declined and there is an increasing interest in the use of IVF to diagnose severe genetic disease in embryos of families at risk. However, little is known about the underlying processes that form the follicles containing the developing germ cells and the matured oocytes needed for IVF. The cohort of oocytes that can be harvested from any patient depends on unknown recruitment processes initiating development of a subset of the quiescent germ cells and happens in an unregulated and spontaneous manner. The present project will identify the known and unknown genes involved in recruitment of oocytes from the basal primordial population. These genes will become candidates for aiding infertile women, improving their response to fertility drugs, the development of novel contraceptive methods and potentially increasing the reproductive life span of women. Knowledge of the genes expressed in oocytes matured in vivo and in vitro will have an important bearing on the long-term opportunity to use fertility drugs in vitro instead of administration to patients for IVF. This would dramatically reduce the cost of IVF and the side-effects of hyperstimulation of ovaries of patients and the associated sequelae. The research project is a discovery program leading to the identification of the genes that govern oogenesis in the human. It is only recently that techniques have been developed to sufficient sensitivity to detect the small quantities of RNA proceeded by active genes in the individual germ cells and oocytes.Read moreRead less