Searchable abstracts of presentations at key conferences in endocrinology

ea0006oc14 | Reproduction | SFE2003

Expression and signaling characteristics of orexin receptors in the human male reproductive system

Karteris E , Chen J , Randeva H

Orexins (A & B) are derived from a common 130 amino acid precursor peptide, prepro-orexin, by proteolytic cleavage, and orchestrate their actions by binding and activating two types of G-protein coupled receptors, orexin-1 receptor (OX1R) and orexin-2 receptor (OX2R). The OX1R preferentially binds orexin-A, whilst OX2R binds both orexin-A and ?B, with similar affinity. Besides playing a role in the regulation of feeding and energy homeostasis, orexins appear to increase se...

ea0002p83 | Signalling | SFE2001

Expression of Orexin-A and and functional Orexin type-2 receptors in human fetal and adult adrenals: Implications in adrenal function and energy homeostatsis

Karteris E , Hillhouse E , Randeva H

Recently, two new peptides named Orexin-A and Orexin-B, have been implicated in the regulation of feeding behaviour. Studies in starved rats have shown that catabolic activity quickly predominates, reinforced by elevated corticosterone, not driven by ACTH, implicating adrenal activity as a metabolic regulator. In view of these findings, we sought to investigate whether orexin and orexin receptors are present in human fetal and adult adrenals, and therefore may be implicated in...

ea0011p391 | Diabetes, metabolism and cardiovascular | ECE2006

Mapping of adiponectin and adiponectin receptors in the human adult and fetal heart

Chen J , Lencioni M , Karteris E , Lehnert H , Randeva HS

Obesity is linked to the development of insulin resistance, diabetes and an increased risk of cardiovascular disease and the metabolic syndrome. Adipose tissue-derived proteins so termed ‘adipokines’ have been implicated in cardiovascular disease and the metabolic syndrome although the molecular mechanisms are not fully understood. Adiponectin, unlike other adipokines, has been shown to have anti-inflammatory, anti-atherogenic, and insulin-sensitising effects. Import...

ea0009p28 | Diabetes and metabolism | BES2005

Expression of adiponectin receptors in fetal and adult human adrenal cortex

Karteris E , Digby J , Chen J , Randeva H

The adrenal gland is implicated in energy homeostasis, and dysfunction of this gland contributes to a variety of metabolic disorders including the development of hypertension, diabetes, osteoporosis, and obesity. Recently, adipokines have been implicated in adrenal function. Adiponectin, an adipokine, with insulin sensitising and anti-inflammatory properties, exerts its effects by activating two distinct seven transmembrane domain receptors, adiponectin-R1 (adipoR1) and -R2 (a...

ea0006p70 | Steroids | SFE2003

Effects of food deprivation on the expression and signalling of orexin and orexin receptors in the rat hypothalamus and adrenal gland

Karteris E , Machado R , Grammatopoulos D , Hillhouse E , Randeva H

Orexins, in addition to regulating food intake and playing a role in the sleep wake cycle, are involved in the activation of HPA axis. Starvation induces metabolic changes in the body, including upregulation of orexin and its receptors in the hypothalamus. We investigated the expression and signalling characteristics of rat orexin receptors at the hypothalamic and adrenal level in food deprived animals and controls. Food deprivation induced both orexin type-1 (OX1R) and type-2...

ea0011oc10 | Steroids and reproductive endocrinology | ECE2006

Progesterone signaling in human myometrium is mediated through two novel membrane G protein coupled receptors

Karteris E , Zervou S , Pang Y , Dong J , Hillhouse EW , Randeva HS , Thomas P

One of the hallmarks of parturition in most mammals is a dramatic drop in plasma levels of progesterone (P4), which promotes myometrial relaxation, prior to labor. In humans and some other primates however, the opposite occurs and placental P4 production increases with advancing pregnancy. The expression of nuclear progesterone receptor (PR)-responsive genes is decreased in the primate uterus at term, which suggests ‘functional’ progestin withdrawal involves repressi...

ea0011p393 | Diabetes, metabolism and cardiovascular | ECE2006

Functional analysis of cardiac orexin receptors: preferential activation by OR-B

Chen J , Karteris E , Rodrigo G , Stanfield P , Ng A , Randeva HS

The family of G-protein coupled receptors (GPCRs) are amongst the best-described regulators of cardiovascular pathophysiology. In rodents, intracerebroventricular administration of orexins increases mean arterial pressure and heart rate. However, important peripheral actions of orexins and their cognate receptors is now increasingly of interest.In this study we demonstrated that both receptors are present across the rat heart, at mRNA and protein level. ...

ea0011p718 | Reproduction | ECE2006

Secretion of adiponectin by human placenta: differential modulation by cytokines

Vatish M , Chen J , Karteris E , Zervou S , Digby JE , Hillhouse EW , Randeva HS

Pregnancy, a state of insulin resistance (IR), is associated with elevated levels of cytokines and profound alterations in metabolism, directed towards supplying adequate nutrition for the fetus. Adiponectin, an adipokine with anti-inflammatory and insulin sensitising properties, plays an important role in energy homeostasis. Interestingly, in gestational diabetes mellitus (GDM), a state of greater insulin resistance, serum adiponectin levels are lower than normal subjects. We...

ea0009p23 | Diabetes and metabolism | BES2005

Upregulation of adiponectin receptors in human adipose tissue from women with the polycystic ovary syndrome(PCOS)

Tan B , Chen J , Digby J , Keay S , Karteris E , Randeva H

PCOS is associated with insulin resistance and dyslipidaemia. Adiponectin receptors (Adipo-R1, Adipo-R2) are expressed in human myotubes. Their mRNA levels were found to be correlated with insulin and circulating triglycerides.The aims of this study, were to investigate the expression of adiponectin and its receptors in adipose tissue from normal and PCOS women (Ethical approval was obtained from the University Hospitals Coventry & Warwickshire NHS T...

ea0009p29 | Diabetes and metabolism | BES2005

Differential modulation of orexin receptors by hyperglycaemia in the mouse heart

Karteris E , Chen J , Zervou S , Pelengaris S , Khan M , Randeva H

Diabetes mellitus, characterised primarily by hyperglycaemia, is associated with a number of cellular stresses and changes that cause cardiomyocytes to adapt with those modifications that characterise the diabetic heart. Although orexins are cardiovascular regulators acting via the brain, little is known about their potentially critical roles in the heart. Orexins exert their actions by activating two distinct G protein coupled receptors, orexin-R1 (OXR1) amd orexin-R2 (OXR2)....