Endocrine Abstracts

Background: Kisspeptin stimulates hypothalamic GnRH secretion resulting in gonadotrophin release and has the potential as a future therapeutic for infertility. Previous studies have observed that kisspeptin increases LH and to a lesser degree FSH when administered to healthy women, which may limit its therapeutic potential. However, studies in women with hypothalamic amenorrhoea show that i.v. infusions of kisspeptin-54 stimulated both LH and FSH equally. Chronic s.c. infusion...

Background: Kisspeptin is an RF amide peptide hormone critical for reproductive function. Kisspeptin is also abundantly expressed in the placenta, where it has an important physiological role in regulating placental invasion. Accordingly, plasma kisspeptin levels rise dramatically during normal pregnancy. Lower plasma levels of kisspeptin are associated with poor pregnancy outcomes such as recurrent miscarriage, intrauterine growth restriction and pre-eclampsia. Urinary measur...

A decade ago, genetic disruption of the kisspeptin signalling pathway was observed to cause hypogonadotrophic hypogonadism. Hypothalamic kisspeptin acts by stimulating secretion of endogenous GnRH. Our research has investigated the physiological effects of kisspeptin in women, with the overarching aim of determining if kisspeptin could be used to treat women with infertility.We initially observed that s.c. bolus injection of kisspeptin acutely stimulated...

Background: Kisspeptin is an RF amide peptide hormone critical for reproductive function. Kisspeptin is also abundantly expressed in the placenta, where it has an important physiological role in regulating placental invasion. Accordingly, plasma kisspeptin levels rise dramatically during normal pregnancy. Lower plasma levels of kisspeptin are associated with poor pregnancy outcomes such as recurrent miscarriage, intrauterine growth restriction and pre-eclampsia. Urinary measur...

Background: It is apparent that COVID-19 may cause persistent symptoms beyond 12 weeks (‘long COVID’). However its underlying pathophysiology is unclear. Several symptoms of long COVID draw similarities to that of endocrine diagnoses. We recently observed that adrenal and thyroid function were normal in survivors of COVID-19 at follow-up. Here we assess additional endocrine axes that could plausibly have a role in long COVID to determine their relationship to ongoing...

Kisspeptin is integral to hypothalamo-pituitary-gonadal (HPG) axis function and overall fertility. Functional deficiency of GnRH/lH secretion in the central reproductive disease, hypothalamic amenorrhoea (HA), indicates diminished kisspeptin signalling. Clinical trials have shown kisspeptin to be a viable therapeutic intervention. However, repeated administration led to the development of tachyphylaxis and so is likely a problem for future implementation. Indeed, elevated LH r...

Introduction: Free ionised calcium is the biologically active component of total circulating calcium but is infrequently measured due to sampling requirements. Therefore, total calcium is ‘adjusted’ for albumin to provide a closer estimate of the biologically active ionised calcium level (e.g. James, Orell, Payne and Berry formulae). Here, we aim to derive a novel equation to estimate ionised calcium from readily available biochemical parameters and compare its perfo...

Background: Due to practical limitations, the diagnosis of hypogonadism is predominantly based on a single measure of reproductive hormones, often with confirmation on a second occasion. Factors associated with reproductive hormone variation include: pulsatile secretion, diurnal rhythm, and food intake, which can affect the accuracy of diagnosis of reproductive disorders. There is limited data quantitatively estimating the variability of reproductive hormone levels over the da...

Section 1: Case history: A 19-year-old British-Asian man presented with a two-year history of gynaecomastia. He had no other symptoms of hypogonadism. He had an unremarkable past medical history, did not take any regular medications and denied the use of any illicit drugs. There was a family history of consanguinity, with his parents being first cousins. On examination, his BMI was 28 kg/m2 and he had post-pubertal-sized testes (20 ml) with normal secondary sexual c...

Background: Successful reproduction relies on integration of sensory cues of attraction with corresponding emotions and behaviours. However, the intrinsic factors integrating these fundamental aspects of human attraction with limbic and reproductive pathways have not been fully identified. Kisspeptin is a crucial activator of the reproductive axis and together with its receptor is widely expressed throughout the limbic and olfactory systems in humans suggesting a potential rol...