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
Cardiovascular Effects Of Enhanced Leptin Signalling
Funder
National Health and Medical Research Council
Funding Amount
$1,200,972.00
Summary
Leptin treatment causes weight loss, but leptin also increases blood pressure. We wish to determine if increasing leptin signalling, by modifying signal transduction pathways within leptin sensitive cells in the brain, can reduce weight without increasing blood pressure.
The key to how the brain works lies in its capacity to modify the strength of its connections. During development, input to the brain from our sensory organs shapes the properties of synaptic contacts and target neurons. This project is aimed at understanding the pathways in the brain related to our sense of hearing, and discovering what is different about these pathways in congenital deafness, where the brain does not receive the appropriate signals during development.
Molecular Mechanisms Underlying The Positive Associations Between Male Gender And Leptin With Barretts Oesophagus
Funder
National Health and Medical Research Council
Funding Amount
$387,489.00
Summary
Barrett's oesophagus is a disease of the gullet that can lead to the development of oesophageal cancer, which has a very poor outcome. We have shown that the risk of Barrett's oesophagus is greatest in obese males with a high blood level of leptin, a hormone made in fat tissue. The aim of this study is to examine how leptin causes this increased cancer risk, so that new treatments or tests for Barrett's and oesophageal cancer can be developed.