Endocrine Abstracts

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...

The epidemic-like increase in obesity in young people is paralleled by a rise in related diseases such as PCOS, especially in pubertal girls. Kisspeptins, encoded by the KiSS1 gene, are firmly linked with the normal control of the reproductive system and loss-of-function mutations are associated with absence of puberty. Although KiSS1 is predominantly expressed in the hypothalamus (HYP), we detected KiSS1 mRNA in rat pituitary (PIT) and adipose tissue (FAT...

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...

Adipokines such as resistin and FIAF (fasting-induced adipose factor) are predominantly, but not exclusively, expressed in adipose tissue and may modulate insulin sensitivity and lipid metabolism. We reported that resistin and fiaf mRNA, and resistin protein, are detectable in the mouse hypothalamus and pituitary gland (see eg. Wiesner et al. 2004). We are investigating the regulation of these genes in a novel hypothalamic neuronal cell line (n-1; Belsham ...

We reported that leptin mRNA is developmentally regulated and hypothesized that local leptin expression is important for the maturation of the hypothalamic-pituitary system. Pituitary leptin mRNA levels were down-regulated in early postnatal male and female rats. We now show that pituitary leptin protein content and expression of the long (OBRb) and short (OBRa) leptin receptor isoforms in the pituitary and hypothalamus also undergo age-related changes. Tissue wa...

Introduction: Secondary hormonal deficiencies (SHD) are frequently observed in patients with pituitary adenomas. We previously reported that pituitary tumour clinical subtypes were associated with specific patterns of SHD, and nonfunctioning adenomas (NFAs) were more likely to present with multiple SHD. We extended our work to examine if the immunohistochemical staining patterns of NFAs impacted SHD.Methods: All clinically NFAs surgically removed between...

A 68 year old gentleman referred to endocrinology clinic with a few years history of erectile dysfunction (ED), which manifested as reduced libido and partial erections. Investigations revealed primary hypogonadism with a low morning serum Testosterone of 4.8 (Ref: 7.9-31 nmol/l), raised FSH at 47 (Ref:1.5-12.4 iu/l) LH at 36.8 (Ref: 1.7-8.6iu/l) and normal thyroid function tests (TFTs). The patient declined testosterone replacement therapy following a discussion of pros and c...

Secondary hormonal deficiency (SHD) in sellar masses (SM) is thought to be partly due to compression of the portal vessels by the enlarging tumour restricting the blood supply to the normal pituitary tissue. However, to date no study has looked at the patterns of SHD in various types of SM and assessed if SHD is related solely to the size of SM or is associated with the underlying pathology. We assessed 914 patients with SM enrolled in our comprehensive pituitary registry sinc...