Endocrine Abstracts

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...

The hypothalamo-pituitary–thyroid (HPT) axis maintains controlled systemic levels of thyroid hormone (TH). This is achieved through negative feedback via the hypothalamic arcuate and paraventricular nuclei. The effects of thyroid hormone in other hypothalamic nuclei are yet to be elucidated. Administration of triiodothyronine (T3, thyroid hormone) into the hypothalamic ventromedial nucleus (VMN) increases food intake in rats. Thyroid hormone activation and inac...

Background: Temporary hypocalcaemia occurs in up to 40% of patients following a total thyroidectomy. Serum calcium and parathyroid hormone (PTH) measurements are currently used to predict post-thyroidectomy hypocalcaemia. However, immediate access to PTH measurement is expensive and not widely available. Serum phosphate responds rapidly to changes in circulating PTH levels and its measurement is readily available in all hospitals. We evaluated the use of serum phosphate to pre...

Background: Kisspeptin is a peptide product of the KiSS-1 gene and a key regulator of the hypothalamo-pituitary-gonadal axis. Pregnancy is associated with raised plasma kisspeptin concentrations. However, there is significant variation in the plasma kisspeptin levels quoted in previous studies. We investigated the effects of pre-analytical factors including processing time and anticoagulant type on plasma kisspeptin-immunoreactivity (IR) measurement.Meth...

3-iodothyronamine (T1AM) is a novel, endogenous rapid acting biogenic amine, which is a potent agonist of the G-protein coupled trace amine-associated receptor 1, TAAR1. It has been suggested that endogenous T1AM could be generated by enzymatic deiodonation and decarboxylation of T4. The presence of T1AM in rat brain and the distribution of the TAAR1 receptor in the hypothalamus suggest that T1AM may affect food intake and regulate e...

Defending body weight is a fundamental homeostatic process. Indeed, countless studies have demonstrated weight-maintaining hyperphagia in response to either increased energy expenditure or a reduction in the caloric density of available food. The principal effector of this adaptive food intake is thought to be the adipose tissue-derived hormone, leptin. According to the classical ’adipostat’ model, the hypoleptinemia resulting from weight loss drives food intake to r...

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...

Background: Functioning gonadotroph adenomas (FGA) are rare benign pituitary tumours. Several case reports suggest that FGA may present with features of ovarian hyperstimulation in women. However, a lack of aggregated clinical experience of FGA precludes the meaningful guidance of management in affected women.Methods: Case series of 7 women presenting at different UK sites with FGA induced ovarian hyperstimulation syndrome (OHSS).R...