Visceral Sensation In Complicated And Uncomplicated Upper Gastrointestinal Disease
Funder
National Health and Medical Research Council
Funding Amount
$66,929.00
Summary
50% of patients with complications of peptic ulcer (bleeding) and gastroesophageal reflux disease (Barrett's Oesophagus) have no symptoms of their diseases. In contrast, 50% of patients who seek treatment for gastrointestinal symptoms are found to have no cause after investigations. The aims of this study are to explore differences in sensation, muscular function and genetic factors between patients with functional gastrointestinal disorders and patients with complicated organic disorders.
How Does Inflammation Of The Gut Change Its Sensory Innervation?
Funder
National Health and Medical Research Council
Funding Amount
$613,767.00
Summary
A large number of patients that are referred to gastroenterologists for pain and discomfort from the bowel are offered no effective treatment. This has a large impact on quality of life and often involves invasive tests to rule out inflammatory or cancerous causes. These patients are classified as suffering from irritable bowel syndrome (IBS). Patients who have diagnosable inflammatory bowel disease (IBD) where colonoscopy is positive may suffer similar symptoms but also have no treatment for th ....A large number of patients that are referred to gastroenterologists for pain and discomfort from the bowel are offered no effective treatment. This has a large impact on quality of life and often involves invasive tests to rule out inflammatory or cancerous causes. These patients are classified as suffering from irritable bowel syndrome (IBS). Patients who have diagnosable inflammatory bowel disease (IBD) where colonoscopy is positive may suffer similar symptoms but also have no treatment for this type of symptom. It is becoming apparent that a large subgroup of IBS patients have undergone prior infection or inflammation, and that there are in fact changes in the types of cells in biopsies from their gut. Thus there are common features to IBS and inflammation. These may provide a means for us to find new treatments for IBS and IBD symptoms. Mice develop similar microscopic changes in the colon after experimental inflammation to those seen in humans, so we can discover more from this model. We have recently established that there are several types of sensory nerve fibres from the mouse colon and rectum that convey information about contractions, distension and chemical mediators released from tissue to the central nervous system. These are almost certainly responsible for generating symptoms in patients. We aim in this project to discover how these sensory nerves change in their responsiveness to mechanical and chemical stimuli in experimental inflammation. Importantly we shall investigate the mediators that are present in the tissue which may activate sensory nerves and-or the receptors on sensory nerves that may be increased. These experiments we hope will provide a target at which to aim novel drug treatments for symptoms of IBS and IBD.Read moreRead less
Mechanisms Of Mechanotransduction In Primary Visceral Afferents
Funder
National Health and Medical Research Council
Funding Amount
$253,500.00
Summary
Mechanotransduction is the process whereby mechanical stimuli are converted into signals in sensory nerves. This forms the basis of touch, hearing, position sense and many aspects of internal perception. It also constitutes a major component of pain. Our group aims to discover the molecular basis of mechanotransduction in mammals, and in particular how it relates to signaling of events in the digestive system. We and our collaborators have been among the first to explore this question, and have ....Mechanotransduction is the process whereby mechanical stimuli are converted into signals in sensory nerves. This forms the basis of touch, hearing, position sense and many aspects of internal perception. It also constitutes a major component of pain. Our group aims to discover the molecular basis of mechanotransduction in mammals, and in particular how it relates to signaling of events in the digestive system. We and our collaborators have been among the first to explore this question, and have found that three genes are responsible for many aspects of mechanotransduction. Each gene is transcribed to produce a channel or pore in the membrane of sensory nerve fibres which responds to mechanical forces by allowing ions to enter and induce electrical signals. Our early findings in mice with disruption of individual genes indicate that a complex positive and negative interaction of these channels must underlie normal mechanotransduction. However, these channels must represent only a part of the transduction mechanism, with extracellular and intracellular anchors inevitably playing a major role. The identity of such anchoring proteins in mammals is currently emerging, and we are fortunate to have access to mice deficient in specific genes that will provide information about candidates for this role. Through our studies on mechanotransduction in the digestive system in parallel with our collaborators' studies on mechanotransduction in skin we shall not only identify the fundamental mechanisms of mammalian mechanotransduction, but also reveal which components of mechanotransducers are peculiar to the gut. Such peculiarities provide molecular targets for therapy of diseases in which alteration of mechanosensory signaling is itself an aim.Read moreRead less
Interaction Of TRP Channels And Inflammatory Mediators: A Critical Role In Visceral Pain
Funder
National Health and Medical Research Council
Funding Amount
$308,747.00
Summary
Transient receptor potential, or TRP channels, are involved in generating many of the sensations we feel, such as touch and pain. The function of these channels can be altered by substances released by the body during inflammation. Some TRP channels have specialized roles in signalling pain from the colon which can be enhanced during colonic inflammation. Understanding how TRP channels and inflammatory mediators function and interact is essential if we are to find treatments for colonic pain.