Endocrine Abstracts

Iain Clarke, Prince Henry's Institute of Medical Research, Clayton, Australia AbstractDr Clarke is a leading researcher in the field of neuroendocrinology. In the early 1980s he and Mr James Cummins (a neurosurgeon at St Vincent's Hospital) developed methodology to enable the collection of blood from the hypophseal portal system. This permitted the first ever measurements of real-life secretions of brain hormones unde...

Professor Clarke graduated from Massey University, New Zealand (B. Agric. Sci., 1971) followed by M. Agric. Sci. (1st Class) in reproductive physiology in 1973). He then obtained his PhD at Edinburgh University, Scotland in 1976, studying endocrinology and behaviour. He has since moved to Australia and became Senior Research Fellow of NHMRC in 1986, rising to Principal Research Fellow in 1991. He became Chairman, D...

The brain controls reproduction through the secretion of GnRH, but a series of higher brain centres control the secretion of GnRH into the hypophysial portal system. Whereas GnRH might be considered the ‘speaker’ for the brain in the reproductive axis, there is significant ‘cross-talk and chatter’ relating to the higher brain centres of control. Most prominently, kisspeptin mediates the feedback effect of sex steroids on GnRH cells, which may be effected at...

As a general rule, hypothalamic neuropeptides that stimulate food intake act to inhibit the reproductive axis. We have studied the functions of two peptide systems in detail. Melanocortins, such as melanocyte stimulating hormone-α, β and γ, are products of the pro-opiomelanocortin (POMC) gene, produced in cells of the arcuate nucleus and act to inhibit feeding. Melanocortins also stimulate the reproductive axis. In lean hypogonadotropic ovariectomised ewes, POMC...

The identification of leptin as a gene product produced in fat revitalised interest in the means by which the brain receives signals to regulate appetite, energy expenditure and the neuroendocrine system. We have studied the effects of alterations in bodyweight on the expression of appetite regulating peptides in the brain and have also determined effects of leptin on a range of parameters in the hypothalamus and pituitary gland of the ovariectomised female sheep. Intracerebro...

Background: Type 1 diabetes (T1D) is a metabolic disease of unknown aetiology that results from the autoimmune destruction of the insulin-producing pancreatic β-cells. Exogenous insulin administration is the only treatment for patients. Partial remission or “honeymoon phase” classically occurs a few weeks after insulin therapy has been initiated. During this stage the patient’s need for exogenous insulin can decline by 50%, and near-normal metabolic control...

Preparations of recombinant insulin and insulin analogues are used in the treatment of insulin-dependent diabetes. Recombinant insulin that corresponds to the human sequence might be expected to cross-react extensively with insulin assays. Insulin analogues contain modifications that alter their action profiles and may therefore interact unpredictably with detection antibodies. In the differential diagnosis of hypoglycaemia it is important to be aware of the extent of the cros...

It is well recognised that the intestinal epithelium has a remarkable capacity to regenerate after high levels of DNA damage or injury. Although the kinetics of this ‘clonogenic repopulation’ whereby a new stem cell repopulates the crypt is understood, little is known about the molecular mechanism underlying this, although upregulation of Musashi-1 is known to mark the process. By conditionally deleting genes that are lethal to the intestinal stem cells we have mimic...

The rising prevalence of childhood obesity is a major public health concern. Approximately 21% of children by the age of eleven are clinically obese, with a further 14% classed as overweight. The causes of obesity of childhood obesity are multifaceted, leading to a complex multi-disciplinary management approach. A high proportion of children and young people do not meet the recommended guidelines of a minimum of 60 minutes physical activity per day. In addition to the barrier&...

Introduction: Childhood obesity continues to prove a major public health concern, with obesity and metabolic syndrome becoming increasingly prevalent in children and young people with type 1 diabetes mellitus (T1DM). Glucagon-like peptide 1 (GLP-1) therapy has shown promising results for weight loss in adults with type 2 diabetes mellitus (T2DM) and has recently been licensed for the treatment of adolescents living with obesity. Liraglutide has been shown to be beneficial in f...