Endocrine Abstracts

Introduction: Adipokines, such as resistin and fasting-induced adipose factor (FIAF), are implicated in the regulation of insulin sensitivity and regulated by nuclear receptors like peroxisome proliferator activated receptor gamma (PPARγ), and retinoic acid receptor alpha (RARα). Primarily expressed in murine fat, we also showed that these adipokines are expressed in the mouse hypothalamus, as well as in N-1 hypothalamic neurons. We hypothesized that rosiglitazone (R...

Introduction: We previously reported the novel finding that leptin, and several other fat-derived hormones (adipokines), is expressed and regulated in rat hypothalamus (1). Subsequently leptin (ob) mRNA was found in human, sheep and pig brain, but was surprisingly undetectable in mouse brain. In the present experiments we used a mouse hypothalamic neuronal cell line to investigate possible inhibitory mechanisms that may prevent mouse neurons from expressing ob mRNA. These incl...

Introduction: The hypothalamic kiss1/kisspeptin system is pivotal in controlling fertility. However, kiss1 transcripts were also quantified in rat fat, where expression was regulated by oestradiol (Brown et al. 2008) and by dihydrotestosterone (DHT; Brown et al. 2009). In human fat, microarray analysis revealed abnormal, multiple gene expression in obese PCOS patients (Corton et al. 2007). In the present experiments we used a rat model (Manne...

Fat-derived adipokine genes that modulate metabolic and inflammatory responses, such as resistin (rstn) and fasting-induced adipose factor (fiaf), are also expressed in mouse brain and pituitary gland. We, and others, reported that central fiaf and rstn mRNA levels were increased following a brain injury-induced inflammatory response, and central injection of resistin reduced food intake and increased hepatic glucose production. Since LPS-induced en...

Kisspeptins, peptide products of the KiSS-1 gene, are pleiotropic hormones best recognized as novel regulators of puberty onset and the reproductive system. Thus, the hypothalamus expresses both KiSS-1 and its receptor, GPR54. Hypothalamic KiSS-1 is attenuated by food restriction (72 h fast),and this provides a plausible link between negative energy balance and the disruption of reproductive function. Hypothalamic KiSS-1 mRNA levels are also reduced...

Aims/hypothesis: Resistin could be implicated in the mechanism of insulin resistance and recent evidence suggests this occurs, in part, via a brain-dependent pathway. Given the emerging role of hypothalamic AMP-activated protein kinase (AMPK) in the modulation of appetite and glucose levels, we hypothesized that its activity would be modulated by resistin. To verify such a pathway, we employed the N-1 hypothalamic neuronal cell line, which expresses a variety of neuropeptides ...