Endocrine Abstracts

The initiation of mammalian puberty requires an increased pulsatile release of gonadotrophin hormone releasing hormone (GnRH) from the hypothalamus. This increase is brought about by changes in transsynaptic and glial–neuronal communication. Coordination of this regulatory neuronal–glial network likely requires the participation of a multiplicity of genes hierarchically arranged within discrete, but interactive, networks. The identity and structural features of at le...

Thyroid hormones are essential for the proper development of a variety of tissues, especially the nervous system. Their transport into target cells is mediated by specific thyroid hormone transporters like the monocarboxylate transporter 8 (MCT8). Mutations in this X-chromosomal gene in humans lead to a severe phenotype characterized by psychomotor retardation, hypotonia, and a striking derangement of serum thyroid hormone levels: high T3 in the presence of low T4, and no sign...

Deiodinases (Dio1-3) are selenium-dependent enzymes that catalyze the reductive removal of iodine from iodothyronines. Depending on the substrate and the position of the iodine removed, deiodination can generate T3 from T4 or inactivate T3 and T4. Local expression of Dio can help to adjust the intracellular levels of T3 to the physiological needs of the organ without changing circulating T3 concentrations. It has been suggested that hepatic Dio1 generates circulating T3. Howev...

The concentration of many neuropeptides in the brains of ectothermic vertebrates is several orders of magnitude higher than in the brains of mammals. We have taken advantage of this singular situation to isolate from the brain of the European green frog, Rana esculenta, a number of regulatory peptides that are orthologous to mammalian neuroendocrine peptides. These include α-MSH, γ-MSH, two tachykinins, two GnRH variants, CRH, PACAP, NPY, CGRP, CNP, GRP, and O...

The 16-kDa N-terminal fragment of human prolactin (16K hPRL) is a potent angiostatic factor described to prevent tumor growth in mouse models. Using microarray experiments, we have dissected how the endothelial-cell genome responds to 16K hPRL treatment. Of the 23.000 transcripts present on the chips, 210 are regulated by 16K hPRL. Bio-informatic analysis and experiments performed on endothelial cells with various chemical inhibitors clearly suggest that NF-κB is crucial ...

The hypothalamic paraventricular nucleus (PVN) is a major regulatory centre of energy homeostasis by possessing the unique capability of simultaneously controlling endocrine axes, water balance and autonomic functions. It receives neuronal information form orexigenic and anorexigenic cell groups of the basal hypothalamus that monitor peripheral metabolic signals (leptin, insulin, ghrelin, glucose, glucocorticoids) and also from brainstem centers relaying sensory information fr...

Evidence has accumulated about the involvement of the CRF system in the regulation of energy balance. The effects of CRF are mediated by two receptors: CRFR1 and CRFR2. The role of the CRFR1 in the regulation of energy balance is not well defined. To address this issue, adult male CRFR1 KO mice and WT littermates were given low fat (LFD) or high-fat (HFD) diets for 4 months. Under LFD no differences between genotypes were seen on body weight (BW) and caloric intake. KO mice ha...

Recent studies using the viral transneuronal tracing technique allowed to reveal brain neurons synaptically connected with the adrenal gland, via specific infections within functionally related chains of neurons. The aim of the present study was to investigate whether cerebral neurons involved in the innervation of the adrenal gland exhibit asymmetry or not. In order to label simultaneously the supraspinal neurons connected with the right- and left-sided adrenal glands, dual-v...

Aim and background: Retinol binding protein 4 (RBP 4) is an adipocyte-secreted molecule causing insulin resistance in transgenic animals. RBP was increased in subjects with impaired glucose tolerance and diabetes type 2. The levels of RBP-4 in PCOS were not investigated till now.Subjects and methods16 lean PCOS (BMI 21.4 (1.75) kg/m2, age 24.1 (4.1) years), 25 obese PCOS (BMI 30.3 (4.8) kg/m2, age 26.3 (5.0) years) and 13 healthy wo...

In humans and rhesus monkeys (Macaca mulatta) the zona reticularis of the adrenal gland produces large amounts of dehydoepiandrosterone (DHEA) and its sulfated form, DHEAS. The circulating levels of these steroids are particularly high during early adulthood, and they then decline gradually during aging, especially in females. To help elucidate the physiological function of this steroidal loss we examined the 24-hour plasma profiles of DHEAS in female rhesus monkeys, us...