Endocrine Abstracts

Ghrelin is a 28 amino acid n-octanoylated peptide which is the natural agonist for the growth hormone secretagogue receptor and which potently stimulates GH release in vivo (1). We studied the effects of a somatostatin infusion on Ghrelin release in normal subjects.STUDY PROTOCOLFour females and five males, 25-40 years of age, body mass index < 28 kg per m2 were studied. Local ethics committee permission was obtained for ...

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There are a number of endocrine changes which occur during the aging process, including changes in the growth hormone – IGF1 axis, a fall in DHEAS levels, changes in the renin-angiotensin system, and alterations in the hypothalamo-pituitary gonadal axis. Testosterone levels decline with age, with an average decrease in testosterone levels of approximately 1.5% per year. The prevalence of subphysiological testosterone levels is approximately 20% by the age of 50 and 50% by...

Anosmin-1, a protein defective in X-linked Kallmann's syndrome (X-KS), presents a structure comprising a cysteine rich N terminus (CR), a whey acid protein (WAP) domain followed by four fibronectin-like III domains (FnIII); and its function is heparan sulphate (HS) dependent. However, anosmin-1 and HS binding affinity is unknown. Although the WAP domain belongs to a protein family demonstrating serine protease inhibitory activity, the interacting serine protease remains to be ...

Introduction: Anosmin-1, which is implicated in the pathogenesis of X-linked Kallmann`s syndrome, consists of a cysteine rich region, followed by a WAP domain and 4 fibronectin type III (FN3) domains. The N-terminal region of anosmin-1, WAP and 1st FN3 domain, is highly conserved in a wide variety of species which suggests that the activity of the protein resides in these conserved segments. Difficulties in the expression of the full-length anosmin-1 by Chinese hamster ovary c...

Hypothalamic GnRH neuronal dysfunction is a frequent cause of hypogonadotrophic hypogonadism (HH) in women with secondary amenohrroea. However, the entity is poorly characterized in men, possibly due to lack of a sensitive equivalent clinical marker of the condition.A 40-year-old man presented with a 7-year history of progressive lack of energy, loss of libido, decreased sexual function, and loss of morning erections. Puberty had occurred normally and h...

We report the case of a 26 year old man who presented to his GP with infertility; biochemical investigations revealed elevated serum free thyroid hormones (FT4 41 pmol/l (12–22); FT3 13.4 pmol/l (2.8–7.1); and a normal TSH (2 pmol/l (0.27–4.2). He was referred to the endocrine department.On examination, he was found to be clinically well though thin (BMI 18), anxious and tremulous. His heart rate was 110 bpm and blood pressure was normal. ...

The defining features of Kallmann's syndrome (KS) are isolated hypogonadotrophic hypogonadism (IHH) and anosmia, the consequences of a GnRH neuronal migratory defect and olfactory bulb agenesis respectively. Additional features in X-linked Kallmann's syndrome (XKI), include unilateral renal agenesis and bimanual synkinesis respectively. XKI results from mutations of KALIG 1, on Xp22.3. The encoded protein anosmin-1, is a hexamodular secreted cell membrane associated extracellu...

IntroductionKallmann syndrome (isolated hypogonadotrophic hypogonadism and anosmia), is caused by loss of KAL-1 function in the developing human olfactory system. Gene function is also conserved in eukaryotes, including nematodes, chick and rodents. However, the precise role of kal-1 in the developing nervous system is unclear. D.melanogaster an ideal model to study kal-1 function, as many molecular aspects of olfactory development are shared with mammal...

IntroductionThe main population of GnRH-1 neurons that control activity of the HPG axis in primates originate in the peripheral olfactory system. Recently, in vitro primary cell cultures from human fetal olfactory epithelium, named FNC-B4, have been shown to express GnRH-1 and are likely to be the precursor of the adult-like GnRH-1 system distribution in the CNS. A number of external and cell-autonomous factors are known to control migration of these spe...