EXPERT OPINION REVIEW Utilizing somapacitan, a long-acting growth hormone formulation, for the treatment of adult growth hormone deficiency: a guide for the clinician.

OBJECTIVE: Somapacitan is the first approved and currently the only long-acting GH (LAGH) formulation in the United States for treatment of adults with growth hormone deficiency (GHD). The aim of this review was to provide a practical approach for clinicians on how to utilize somapacitan in the treatment of adults with GHD. METHODS: Literature search was performed on PubMed using key words, including adult growth hormone deficiency, long-acting growth hormone, somapacitan, treatment and management. The discussion of treatment aspects utilizing somapacitan was based on evidence from previous clinical studies and personal experience. RESULTS: Clinical trial data demonstrated that somapacitan, a once-weekly reversible albumin-binding GH derivative, decreased truncal fat, improved visceral fat and lean body mass, increased IGF-I standard deviation score and exerted neutral effects on glucose metabolism. Overall, somapacitan was well-tolerated, adverse event rates were comparable with daily GH, anti-somapacitan or anti-GH antibodies were not detected, and treatment satisfaction was in favor of somapacitan vs daily GH. CONCLUSION: Somapacitan is an efficacious, safe, convenient and well-tolerated once-weekly LAGH formulation that reduces the treatment burden of once-daily GH injections for adults with GHD. This article provides a review of the pharmacology of somapacitan and offers practical recommendations based on previous clinical trial data on how to initiate, dose titration, monitoring and dose adjustments whilst on therapy in adults with GHD. Timing of measurement of serum insulin-like growth factor-I levels, information on administration, recommendations on missed doses, and clinical recommendations on dosing in certain sub-population of patients are also discussed.

Detection of the GH analog somatrogon in sports drug testing: Immunological approaches and LC-HRMS/MS.

Due to the presumed lipolytic and anabolic properties, the misuse of human growth hormone (hGH) and its synthetic analogs in sports is prohibited both in- and out-of-competition. Within this research project, the detectability of somatrogon, a recombinant fusion glycoprotein of 22 kDa hGH and the C-terminal peptide (CTP) of the human chorionic gonadotropin (hCG) ß-subunit, with current WADA-approved doping control assays for hGH and hCG was investigated. For that purpose, cross-reactivity tests and a somatrogon administration study were conducted, and only "Kit 2" of the GH isoform differential immunoassays proved applicable to the detection of somatrogon administration in serum. In urine, the immunoassay specific for total hCG yielded presumptively positive findings for several post-administration samples, which can probably be attributed to the presence of an immunoreactive fragment of the hCG ß-subunit. As the detectability of somatrogon with these approaches was found to be limited, a highly specific detection assay (LOD: 10 ng/mL) for the drug in serum samples was developed by using affinity purification with GH receptor (GHR)-conjugated magnetic beads, proteolytic digestion, and liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). Following optimization, the approach was comprehensively characterized, and authentic post-administration serum samples were successfully analyzed as proof-of-concept, indicating a detection window of at least 96 h. Consequently, the presented method can be employed to confirm the presence of somatrogon in serum samples, where only "Kit 2" of the currently used immunoassay kits yielded an abnormally high Rec/Pit ratio.

Growth Hormone Receptor Antagonist Markedly Improves Gemcitabine Response in a Mouse Xenograft Model of Human Pancreatic Cancer.

Chemotherapy treatment against pancreatic ductal adenocarcinoma (PDAC) is thwarted by tumoral activation of multiple therapy resistance pathways. The growth hormone (GH)-GH receptor (GHR) pair is a covert driver of multimodal therapy resistance in cancer and is overexpressed in PDAC tumors, yet the therapeutic potential of targeting the same has not been explored. Here, we report that GHR expression is a negative prognostic factor in patients with PDAC. Combinations of gemcitabine with different GHR antagonists (GHRAs) markedly improve therapeutic outcomes in nude mice xenografts. Employing cultured cells, mouse xenografts, and analyses of the human PDAC transcriptome, we identified that attenuation of the multidrug transporter and epithelial-to-mesenchymal transition programs in the tumors underlie the observed augmentation of chemotherapy efficacy by GHRAs. Moreover, in human PDAC patients, GHR expression strongly correlates with a gene signature of tumor promotion and immune evasion, which corroborate with that in syngeneic tumors in wild-type vs. GH transgenic mice. Overall, we found that GH action in PDAC promoted a therapy-refractory gene signature in vivo, which can be effectively attenuated by GHR antagonism. Our results collectively present a proof of concept toward considering GHR antagonists to improve chemotherapeutic outcomes in the highly chemoresistant PDAC.

Diagnostic characteristics and management outcome in patients with acromegaly: A 15-year experience at a tertiary care hospital in Pakistan.

OBJECTIVE: To assess the diagnostic features of acromegaly, and analyse its management outcomes over a 15-year period in a tertiary care setting. METHODS: The descriptive, cohort, retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of adult patients of either gender diagnosed with acromegaly based on biochemical and radiological evidence between January 2005 and December 2019. Data was retrieved from the medical records. Data was analysed using SPSS 19. RESULTS: Of the 84 subjects, 54(64.3%) were males and 30(35.7%) were female. The overall mean age was 38.69±13.52 years. The patients presented 5.43±4.3 years after the onset of symptoms, with somatic growth features, such as enlarged hands and feet which was the most common complaint 81(96.4%). Of all the patients, 73(86.9%) underwent trans-sphenoidal surgery for the removal of the pituitary adenoma, while 11(13.1%) opted out of the surgical option. Further, 9(12.3%) patients showed biochemical and radiological remission 6 months post-surgery. Out of the remaining 64(87.7%) patients, 38(59.4%) received radiosurgery or radiotherapy, 15(23.4%) underwent repeat trans-sphenoidal surgery, and 11(17.2%) chose medical treatment. CONCLUSIONS: Majority of patients failed to achieve remission after trans-sphenoidal surgery, which is the first line of treatment. Radiotherapy/repeat surgery was generally the options taken by those with persistent disease.

Effect of ß-hydroxybutyrate acid on gene expression levels of antioxidant biomarkers and growth hormone-related genes in liver cell culture.

Introduction: In dairy cattle, oxidative stress is a predominant problem associated with diseases and reproductive health issues. This study aimed to detect the variation in the antioxidant biomarkers by adding different concentrations of ß-hydroxybutyric acid (BHBA) and sought to elucidate its effects on the gene expression levels of growth hormone (GH) and antioxidant biomarkers in bovine hepatocytes. Material and Methods: Four antioxidant biomarkers, namely malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH Px) were evaluated using commercially available bovine ELISA kits. The expression levels of the bovine GH, its receptor (GHR), insulin-like growth factor (IGF), IGF-1, IGF-1 receptor, CAT, SOD, GSH-Px and ß-actin (as a reference) genes in liver cell culture were determined by reverse transcriptase-PCR assay. Results: With the increase of BHBA concentration and culture time, the activities of SOD, CAT, and GSH Px biomarkers in hepatocytes decreased. However, the content of MDA in hepatocytes increased gradually with the increase of hepatocyte culture time and BHBA concentration. The qPCR results revealed that after adding BHBA, gene expression levels of GSH-Px, SOD and IGF biomarkers in hepatocytes began to differ in the culture groups at 12 h, whereas the gene expression level of the CAT and GHR biomarkers in hepatocytes began to differ at 6 h. Conclusion: Quantitative PCR results showed that the BHBA significantly downregulated the expression levels of the GHR gene and CAT, GSH Px and SOD antioxidant biomarker genes.

Carotid Intima-Media Thickness and Cardiometabolic Profile in Turner Syndrome: A Cross-Sectional Study.

INTRODUCTION: Turner syndrome (TS), one of the most common chromosomal abnormalities in females, often results in adult cardiovascular and metabolic complications. Information on pediatric age is scarce. This study aimed to compare the presence of cardiometabolic risk factors in children with TS and healthy controls. METHODS: This is a cross-sectional study comparing patients with TS to age-matched healthy controls, regarding cardiometabolic risk factors including lipid profile, fasting glucose, insulin resistance, body composition, body mass index, blood pressure, and carotid intima-media thickness (cIMT). RESULTS: We included nine TS patients and nine controls with a median age of 13 years (9-14 years). Three TS patients and three controls were prepubertal. All TS patients received growth hormone treatment (GHT), median treatment of six years (3-10 years); four patients underwent treatment with estradiol. No statistically significant differences were detected between TS patients and controls regarding body mass index (BMI), cholesterol levels, and insulin resistance. cIMT indexed to body surface area showed no significant differences between TS patients and controls (0.37 vs 0.35 mm/m2, respectively, p=0.605). TS patients had lower body fat levels (7.2% vs 34.9%, p=0.004). On the other hand, TS patients had higher levels of systolic (z-score 1.04 vs -0.08, p=0.001) and diastolic (z-score 1.08 vs 0.33, p=0.031) blood pressure (BP) and aspartate (AST) and alanine (ALT) aminotransferase levels (26 vs 20 U/L, p=0.008 and 19 vs 14 U/L, p=0.004, respectively). CONCLUSION: Patients with TS, all submitted to GHT, had lower body fat levels compared with controls, despite similar BMI. Although we found no differences in cIMT between the two groups, young girls with TS had higher BP and transaminase levels. Early anthropometric, cardiovascular, and analytical monitoring of patients with TS is essential to detect abnormalities and prevent further complications.

Growth hormone improves insulin resistance in visceral adipose tissue after duodenal-jejunal bypass by regulating adiponectin secretion.

BACKGROUND: The mechanism of improvement of type 2 diabetes after duodenal-jejunal bypass (DJB) surgery is not clear. AIM: To study the morphological and functional changes in adipose tissue after DJB and explore the potential mechanisms contributing to postoperative insulin sensitivity improvement of adipose tissue in a diabetic male rat model. METHODS: DJB and sham surgery was performed in a-high-fat-diet/streptozotocin-induced diabetic rat model. All adipose tissue was weighed and observed under microscope. Use inguinal fat to represent subcutaneous adipose tissue (SAT) and mesangial fat to represent visceral adipose tissue. RNA-sequencing was utilized to evaluate gene expression alterations adipocytes. The hematoxylin and eosin staining, reverse transcription-quantitative polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay were used to study the changes. Insulin resistance was evaluated by immunofluorescence. RESULTS: After DJB, whole body blood glucose metabolism and insulin sensitivity in adipose tissue improved. Fat cell volume in both visceral adipose tissue (VAT) and SAT increased. Compared to SAT, VAT showed more significantly functional alterations after DJB and KEGG analysis indicated growth hormone (GH) pathway and downstream adiponectin secretion were involved in metabolic regulation. The circulating GH and adiponectin levels and GH receptor and adiponectin levels in VAT increased. Cytological experiment showed that GH stimulated adiponectin secretion and improve insulin sensitivity. CONCLUSION: GH improves insulin resistance in VAT in male diabetic rats after receiving DJB, possibly by increasing adiponectin secretion.

Measuring the Scientific Impact of Growth Hormone Treatment in Burns: A Bibliometric Analysis Based on CiteSpace.

This study utilized CiteSpace software to conduct a bibliometric analysis of the literature related to the use of growth hormone in treating burns. The results showed that the research on this topic has attracted increasing attention from scholars worldwide, with the number of publications increasing annually. The research teams and institutions involved in this field are mainly concentrated in China, followed by the United States, Russia, and other countries. The analysis also revealed the prominent co-cited literature and the most influential authors in the field, such as Herndon，DN.and Li Y. The main research themes identified in the literature included the effects of growth hormone on wound healing, tissue repair and regeneration, inflammatory responses, and cell proliferation. Additionally, the research on the clinical applications of growth hormone in burn treatment has been expanded to include areas such as metabolic regulation, immune function, and the prevention of infections. The findings of this study provide useful insights into the current status and future directions of research in the field of growth hormone treatment of burns.

Differential peptide-dependent regulation of growth hormone (GH): A comparative analysis in pituitary cultures of reptiles, birds, and mammals.

Growth hormone (GH) is a pituitary protein that exerts pleiotropic roles in vertebrates. The mechanisms regulating GH synthesis and secretion are finely controlled by hypothalamic neuropeptides and other factors. These processes have been considerably studied in mammals but are still poorly understood in other groups. To better understand the pituitary GH regulation during vertebrate phylogeny, we compared the effects of incubating several peptides on cultures of ex-vivo pituitary fragments obtained from representative specimens of reptiles (iguana), birds (chicken) and mammals (rat). The peptides used were: growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), pituitary adenylate cyclase-activating polypeptide (PACAP), ghrelin, gonadotropin-releasing hormone (GnRH), and somatostatin (SST). In rat pituitary cultures, GH secretion was stimulated by GHRH and TRH, while gh mRNA expression was increased by GHRH and PACAP. In the case of chicken pituitaries, GH release was promoted by GHRH, ghrelin, PACAP, and GnRH, although the latter two had a dual effect since at a shorter incubation time they decreased GH secretion; in turn, gh mRNA expression was significantly stimulated by TRH, PACAP, and GnRH. The most intense effects were observed in iguana pituitary cultures, where GH secretion was significantly augmented by GHRH, PACAP, TRH, ghrelin, and GnRH; while gh mRNA expression was stimulated by GHRH, TRH, and PACAP, but inhibited by ghrelin and SST. Also, in the three species, SST was able to block the GHRH-stimulated GH release. Furthermore, it was found that the expression of Pou1f1 mRNA was increased with greater potency by GHRH and PACAP in the iguana, than in chicken or rat pituitary cultures. Additionally, in-silico analysis of the gh gene promoter structures in the three species showed that the reptilian promoter has more Pit-1 consensus binding sites than their avian and mammalian counterparts. Taken together, results demonstrate that pituitary peptide-mediated GH regulatory mechanisms are differentially controlled along vertebrate evolution.

Time to first remission and survival in patients with acromegaly: Evidence from the UK Acromegaly Register Study (UKAR).

OBJECTIVE: This study aimed to understand the effect of time to remission of acromegaly on survival in people living with acromegaly. DESIGN, PATIENTS AND MEASUREMENT: This cross-sectional study used data from the UK Acromegaly Register. We considered remission of acromegaly growth hormone controlled at ≤2 µg/L following the diagnosis of acromegaly. We used the accelerated failure time model to assess the effect of time to remission on survival in acromegaly. RESULTS: The study population comprises 3569 individuals with acromegaly, with a median age of diagnosis of 47.3 (36.5-57.8) years, 48% females and a majority white population (61%). The number of individuals with the first remission of acromegaly was 2472, and the median time to first remission was 1.92 (0.70-6.58) years. In this study, time to first remission in acromegaly was found to have a significant effect on survival (p < .001); for every 1-year increase in time to first remission, there was a median 1% reduction in survival in acromegaly. In an analysis adjusted for covariates, the survival rate was 52% higher (p < .001) in those who underwent surgery as compared to those who did not have surgery, 18% higher (p = .01) in those who received treatment with somatostatin analogues (SMA) as compared to those with dopamine agonists and 21% lower (p < .001) in those who received conventional radiotherapy as compared to those who did not receive radiotherapy. CONCLUSION: In conclusion, this population-based study conducted in patients with acromegaly revealed that faster remission time, surgical intervention and treatment with SMA are linked to improved survival outcomes.

Endocrine Outcomes and Associated Predictive Factors for Somatotrophin Pituitary Adenoma after Endoscopic Endonasal Transsphenoidal Surgery: 10 Years of Experience in a Single Institute.

Objective Biochemical remission rates of endoscopic endonasal transsphenoidal surgery (EETS) and its associated predictive factors were evaluated in patients with somatotrophin pituitary adenomas. Methods The patients who underwent EETS in Jinling Hospital were identified between 2011 and 2020. The surgeons' experience, preoperative insulin-like growth factor 1 (IGF-1), basal growth hormone (GH) levels, nadir GH levels, and the tumor characteristics were analyzed for their relationships with endocrine outcomes. Total 98 patients were included for single factor analysis and regression analysis. They were divided into three groups according to the admission chronologic order. Results The overall remission rate of the patients was 57% (56/98) for all the patients over 10 years. In the single factor analysis, we found that the tumor size, cavernous invasion, and sellar invasion were valuable to predict the endocrine outcome after surgery. As for the suprasellar invasion, no significant difference was found between the noninvasive group and the invasive group. The preoperative IGF-1 level ( p = 0.166), basal GH level ( p = 0.001), and nadir GH level ( p = 0.004) were also different between the remission group and the nonremission group in the single factor analysis. The logistic regression analysis indicated that the preoperative nadir GH (odds ratio = 0.930, 95% confidence interval = 0.891-0.972, p = 0.001) was a significant predictor for the endocrine outcomes after surgery. Conclusion The surgeons' experience is an important factor that can affect the patients' endocrine outcomes after surgery. The macroadenomas with lateral invasion are more difficult to cure. Patients with higher preoperative nadir GH levels are less likely to achieve remission.

Decreased ß-cell volume and insulin secretion but preserved glucose tolerance in a growth hormone insensitive pig model.

PURPOSE: Growth hormone (GH) is a central regulator of ß-cell proliferation, insulin secretion and sensitivity. Aim of this study was to investigate the effect of GH insensitivity on pancreatic ß-cell histomorphology and consequences for metabolism in vivo. METHODS: Pancreata from pigs with growth hormone receptor deficiency (GHR-KO, n = 12) were analyzed by unbiased quantitative stereology in comparison to wild-type controls (WT, n = 12) at 3 and 7-8.5 months of age. In vivo secretion capacity for insulin and glucose tolerance were assessed by intravenous glucose tolerance tests (ivGTTs) in GHR-KO (n = 3) and WT (n = 3) pigs of the respective age groups. RESULTS: Unbiased quantitative stereological analyses revealed a significant reduction in total ß-cell volume (83% and 73% reduction in young and adult GHR-KO vs. age-matched WT pigs; p < 0.0001) and volume density of ß-cells in the pancreas of GHR-KO pigs (42% and 39% reduction in young and adult GHR-KO pigs; p = 0.0018). GHR-KO pigs displayed a significant, age-dependent increase in the proportion of isolated ß-cells in the pancreas (28% in young and 97% in adult GHR-KO vs. age-matched WT pigs; p = 0.0009). Despite reduced insulin secretion in ivGTTs, GHR-KO pigs maintained normal glucose tolerance. CONCLUSION: GH insensitivity in GHR-KO pigs leads to decreased ß-cell volume and volume proportion of ß-cells in the pancreas, causing a reduced insulin secretion capacity. The increased proportion of isolated ß-cells in the pancreas of GHR-KO pigs highlights the dependency on GH stimulation for proper ß-cell maturation. Preserved glucose tolerance accomplished with decreased insulin secretion indicates enhanced sensitivity for insulin in GH insensitivity.

Growth Hormone Treatment in Children of Normal Height.

The increased availability of recombinant human growth hormone (rhGH), albeit at a relatively high cost, has increased a demand for treatment of children and adolescents of normal height to increase their adult stature. There are no scientific reports on the efficacy and safety of rhGH therapy in this condition, therefore, the authors comment on the possible causes and consequences based on their personal opinion and experience. As in gigantism, when GH action and end-organ are normal, enough GH is expected to result in increased growth velocity. Short-term adverse effects related to rhGH therapy for approved indications of short stature in children have been very rare. Data on long-term adverse effects are still scarce. A small increase in height might be statistically significant but not functionally or socially relevant. Considering that an increase in height represents more a desire than a need, physicians should emphasize the normality and qualities of these children, discuss with families' alternatives, such as counseling, and refrain from supporting the concept that taller is better.

Robust growth hormone responses to GH-releasing peptide 2 in adolescents.

OBJECTIVES: GH-releasing peptide-2 (GHRP2) can be used for provocative growth hormone testing (GHT). Since it acts as a powerful stimulus for GH secretion, cut-off peak GH level in GHRP2 loading test (GHRP2T) is higher than in other GHT. Nevertheless, data on response at adolescents are limited. This report aimed to investigate peak GH levels in GHRP2T in adolescents. METHODS: Clinical data of adolescents after onset of puberty who underwent GHRP2T at our institution from May 2010 to March 2023 were collected retrospectively. Subjects were classified into three groups according to underlying diseases. RESULTS: Total 23 patients were included: 12 in organic or genetic GHD (o/gGHD) group, three in idiopathic GHD (iGHD) group, and eight in short stature (SS) group. The median GH peak levels were 3.4 ng/mL in o/gGHD group, 88.9 ng/mL in iGHD group, and 90.1 ng/mL in SS group, indicating a robust response of GH peak levels in iGHD and SS groups. Two patients exceeded the cut-off for GHRP2T but below for other GHT, indicating the current cut-off for GHRP2T may miss some GHD patients. CONCLUSIONS: The GH response to GHRP2T in adolescents except the o/gGHD group may be robustly responsive. For the correct diagnosis of GHD, the cut-off peak GH levels in GHRP2T in adolescents may require revisiting.

Preparation and characterization of the injectable pH- and temperature-sensitive pentablock hydrogel containing human growth hormone-loaded chitosan nanoparticles via electrospraying.

This research investigated the in vivo gelation, biodegradation, and drug release efficiency of a novel injectable sensitive drug delivery system for human growth hormone (HGh). This composite system comprises pH- and temperature-sensitive hydrogel, designated as oligomer serine-b-poly(lactide)-b-poly(ethylene glycol)-b-poly(lactide)-b-oligomer serine (OS-PLA-PEG-PLA-OS) pentablock copolymer, as matrix and electrosprayed HGh-loaded chitosan (HGh@CS) nanoparticles (NPs) as principal material. The proton nuclear magnetic resonance spectrum of the pH- and temperature-sensitive OS-PLA-PEG-PLA-OS pentablock copolymer hydrogel proved that this copolymer was successfully synthesized. The HGh was encapsulated in chitosan (CS) NPs by an electrospraying system in acetic acid with appropriate granulation parameters. The scanning electron microscopy images and size distribution showed that the HGh@CS NPs formed had an average diameter of 366.1 ± 214.5 nm with a discrete spherical shape and dispersed morphology. The sol-gel transition of complex gel based on HGh@CS NPs and OS-PLA-PEG-PLA-OS pentablock hydrogel was investigated at 15 °C and pH 7.8 in the sol state and gelled at 37 °C and pH 7.4, which is suitable for the physiological conditions of the human body. The HGh release experiment of the composite system was performed in an in vivo environment, which demonstrated the ability to release HGh, and underwent biodegradation within 32 days. The findings of the investigation revealed that the distribution of HGh@CS NPs into the hydrogel matrix not only improved the mechanical properties of the gel matrix but also controlled the drug release kinetics into the systematic bloodstream, which ultimately promotes the desired therapeutic body growth depending on the distinct concentration used.

Association of circulating leptin, growth hormone, and ghrelin with fibromyalgia: A meta-analysis.

OBJECTIVE: The aim of this study was to evaluate the relationship between levels of leptin, growth hormone (GH), and ghrelin in the bloodstream and fibromyalgia. METHODS: We conducted a meta-analysis to compare the serum/plasma levels of leptin, GH, and ghrelin in individuals with fibromyalgia, as compared to healthy controls. The analysis included sixteen articles, which provided data from 697 fibromyalgia patients and 560 controls. RESULTS: The meta-analysis found that there was no significant difference in leptin levels between fibromyalgia patients and controls overall (SMD = 0.324, 95% CI = -0.264 to 0.913, P = 0.281). However, when subgroup analysis was done based on geographically different populations, it showed a positive association between high leptin levels and fibromyalgia in European populations (SMD = 1.131, 95% CI = 0.197 to 2.064, P = 0.018), while no significant association was found in Latin American populations (SMD = -0.160, 95% CI = -0.847 to 0.528, P = 0.649). As for GH levels, there was no significant difference between fibromyalgia patients and controls overall (SMD = -0.903, 95% CI = -2.036 to 0.231, P = 0.119). However, when subgroup analysis was done based on geographically different populations, it revealed a significant decrease in GH levels in European populations with fibromyalgia (SMD = -2.341, 95% CI = -3.664 to -1.017, P = 0.001), while no significant association was found in North American populations. Lastly, the analysis of ghrelin levels showed no significant association with fibromyalgia overall (SMD = -0.661, 95% CI = -1.382 to 0.059, P = 0.072). CONCLUSION: This meta-analysis shows that patients with fibromyalgia in Europeans have significantly higher levels of circulating leptin and GH. However, no significant association was found between ghrelin levels and fibromyalgia.

Nucleus accumbens ghrelin signaling controls anxiety-like behavioral response to acute stress.

BACKGROUND: Anxiety disorders are one of the most common mental disorders. Ghrelin is a critical orexigenic brain-gut peptide that regulates food intake and metabolism. Recently, the ghrelin system has attracted more attention for its crucial roles in psychiatric disorders, including depression and anxiety. However, the underlying neural mechanisms involved have not been fully investigated. METHODS: In the present study, the effect and underlying mechanism of ghrelin signaling in the nucleus accumbens (NAc) core on anxiety-like behaviors were examined in normal and acute stress rats, by using immunofluorescence, qRT-PCR, neuropharmacology, molecular manipulation and behavioral tests. RESULTS: We reported that injection of ghrelin into the NAc core caused significant anxiolytic effects. Ghrelin receptor growth hormone secretagogue receptor (GHSR) is highly localized and expressed in the NAc core neurons. Antagonism of GHSR blocked the ghrelin-induced anxiolytic effects. Moreover, molecular knockdown of GHSR induced anxiogenic effects. Furthermore, injection of ghrelin or overexpression of GHSR in the NAc core reduced acute restraint stress-induced anxiogenic effects. CONCLUSIONS: This study demonstrates that ghrelin and its receptor GHSR in the NAc core are actively involved in modulating anxiety induced by acute stress, and raises an opportunity to treat anxiety disorders by targeting ghrelin signaling system.

Growth hormone receptor antagonist pegvisomant and its role in the medical therapy of growth hormone excess.

Pegvisomant is a growth-hormone (GH) receptor antagonist that prevents the formation of the active heterotrimer of the dimerised GH receptor and the GH molecule necessary for downstream signal transduction. Over the past 20 years, it has become a key therapeutic option for physicians treating syndromes of GH/IGF-1 excess. Sufficient longitudinal follow-up data suggest that it can be deemed both safe and effective. It is the drug with the greatest potential for achieving an amelioration of the biochemical effects of GH excess with a corresponding normalisation of IGF-1 levels; however, insufficient dose titration has lessened real-world therapeutic outcomes. Theoretical concerns about stimulating tumour growth have been resolved as this has not been observed, while derangement of liver enzymes and local skin-related adverse reactions may occur in a minority of the patients. It may be a particularly impactful medication for the treatment of children, young people, and those with inherited disorders of GH excess, where other treatment modalities often fail. Combination therapy of pegvisomant with first- and second-generation somatostatin receptor ligands or with dopamine agonists remains an ongoing area of interest and research. High cost remains a barrier to the use of pegvisomant in many settings.