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
A man's reproductive health and fertility is affected by processes that occur long before adulthood. The testis and sperm precursor cells first form in the fetus and then grow until the time of puberty, when the upper limit for sperm production is set. This project studies how one key signaling molecule, activin, helps establish normal testicular architecture and drives maturation of sperm precursor cells, and how it contributes to aberrent function in men with testicular cancer.
Gonadotropin Inhibitory Hormone As A Major Regulator Of Reproduction In Mammals
Funder
National Health and Medical Research Council
Funding Amount
$623,378.00
Summary
Reproduction is controlled by the brain and it has been well established that gonadotropin releasing hormone (GnRH) is the primary stimulatory factor. GnRH stimulates the pituitary gland to produce and secrete hormones that, in turn, stimulate the ovaries and testes. It is becoming clear that the brain also produces an inhibitory factor and this project aims to establish that it (gonadotropin inhibitory hormone; GnIH) is functional in mammals.
The Sertoli Cell: Master Regulator Of Hormone-induced Spermatogenic Development
Funder
National Health and Medical Research Council
Funding Amount
$563,536.00
Summary
This project will determine the key roles of major hormones (testosterone, follicle-stimulating hormone, Vitamin A) in Sertoli cells, unique highly specialised cells found in the testis that provide essential nutritional and structural support for sperm production. This research will provide new understanding of the biological pathways controlling sperm development, leading to new molecular targets for infertility or cancer treatment or diagnosis, or new contraceptive strategies for men.
Defining The Role Of Activin C In Gonadal And Adrenal Tumorigenesis
Funder
National Health and Medical Research Council
Funding Amount
$441,511.00
Summary
Activins are members of the inhibin/TGF_ superfamily of growth and differentiation factors. Our published work implicates one of them, activin-_C as a regulator of activin A synthesis and/or its action. To test our hypothesis we will cross activin-_C over-expressing mice (ActC++ ) with inhibin a subunit knock-out mice (_-KO) that develop gonadal and adrenal tumourigenesis and is caused by increased activin A. We predict that if correct, we will prevent or delay reproductive and adrenal tumourige ....Activins are members of the inhibin/TGF_ superfamily of growth and differentiation factors. Our published work implicates one of them, activin-_C as a regulator of activin A synthesis and/or its action. To test our hypothesis we will cross activin-_C over-expressing mice (ActC++ ) with inhibin a subunit knock-out mice (_-KO) that develop gonadal and adrenal tumourigenesis and is caused by increased activin A. We predict that if correct, we will prevent or delay reproductive and adrenal tumourigenesis and prolong survival.Read moreRead less
The Function Of Gametogenenin In Male Fertility And Embryogenesis
Funder
National Health and Medical Research Council
Funding Amount
$537,579.00
Summary
We have identified gametogenetin as novel protein involved in sperm production and in the very earliest stages of embryo survival. It is found within the sperm tail where it binds to cysteine-rich secretory protein 2. The aim of this project is to further refine the biochemistry of GGN using a combination of binding studies, expression analyses and the characterization of two unique mouse models. This project has direct relevance to the causes of human infertility and contraceptive development.