Endocrine Abstracts

The hypothalamo-pituitary–thyroid (HPT) axis serves to maintain appropriate systemic levels of thyroid hormone (TH) through a negative feedback pathway via the hypothalamic arcuate and paraventricular nuclei. However, the effects of TH in other hypothalamic regions are poorly understood. Triiodothyronine (T3) administration to the hypothalamic ventromedial nucleus (VMN) induces a potent hyperphagic response, although it is unclear whether this is part of a nove...

Attenuated glucoprivic feeding responses are a feature of hypoglycaemic unawareness in insulin-treated diabetes. Glucose alters the activity of hypothalamic neurones involved in regulating appetite. Arcuate nucleus (ARC) Neuropeptide Y (NPY) releasing neurones stimulate feeding. The identification of glucose-sensitive NPY releasing hypothalamic neurones suggests a strong role for these neurones in mediating changes in appetite induced by alterations of glucose. To gain a bette...

The hypothalamus regulates multiple homeostatic systems, and is essential for the regulation of appetite and energy balance. Neuropeptide Y, a 36 amino acid peptide and member of the PP-fold family, is a key hypothalamic neuropeptide involved in the regulation of energy balance, potently stimulating food intake following central administration. NPY is expressed in the arcuate nucleus (ARC) and NPYergic neurones project to multiple hypothalamic nuclei and extra-hypothalamic sit...

Hypoglycaemia and hypoglycaemia unawareness severely limit the optimal management of diabetes mellitus and cause recurrent morbidity and even mortality in intensively controlled patients. Altered hypothalamic glucose sensing has been implicated in the development of defective counter regulatory responses to insulin induced hypoglycaemia and hypoglycaemic unawareness. This change in hypothalamic glucose sensing has been attributed, at least in part, to an increase in glucokinas...

The hypothalamo-pituitary–thyroid (HPT) axis maintains controlled systemic levels of thyroid hormone (TH). This is achieved through negative feedback via the hypothalamic arcuate and paraventricular nuclei. The effects of thyroid hormone in other hypothalamic nuclei are yet to be elucidated. Administration of triiodothyronine (T3, thyroid hormone) into the hypothalamic ventromedial nucleus (VMN) increases food intake in rats. Thyroid hormone activation and inac...

As the nation gets fatter, the incidence of diabetes is also rising. The brain is now emerging as a critical mediator of blood sugar control, re-directing focus away from the traditional pancreas-centred model. The enzyme glucokinase (GK) acts as a glucose sensor in many tissues including glucose-sensitive neurones within the hypothalamic arcuate nucleus. However, the role of GK here is unclear. We investigated the role of arcuate GK in glucose homeostasis in both healthy and ...