Administration Of Adrenocorticotropic Hormone Research Articles

Neurobehavioral and molecular changes in a rodent model of ACTH-induced HPA axis dysfunction

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is linked to the pathophysiology of depression. Although exogenous adrenocorticotropic hormone (ACTH) is associated with a depressive-like phenotype in rodents, comprehensive neurobehavioral and mechanistic evidence to support these findings are limited. Sprague-Dawley rats (male, n = 30; female, n = 10) were randomly assigned to the control (male, n = 10) or ACTH (male, n = 20; female n = 10) groups that received saline (0.1 ml, sc.) or ACTH (100 μg/day, sc.), respectively, for two weeks. Thereafter, rats in the ACTH group were subdivided to receive ACTH plus saline (ACTH_S; male, n = 10; female, n = 5; 0.2 ml, ip.) or ACTH plus imipramine (ACTH_I; male, n = 10; female, n = 5;10 mg/kg, ip.) for a further four weeks. Neurobehavioral changes were assessed using the forced swim test (FST), the sucrose preference test (SPT), and the open field test (OFT). Following termination, the brain regional mRNA expression of BDNF and CREB was determined using RT-PCR. After two-weeks, ACTH administration significantly increased immobility in the FST (p = 0.03), decreased interaction with the center of the OFT (p < 0.01), and increased sucrose consumption (p = 0.03) in male, but not female rats. ACTH administration significantly increased the expression of BDNF in the hippocampus and CREB in all brain regions in males (p < 0.05), but not in female rats. Imipramine treatment did not ameliorate these ACTH-induced neurobehavioral or molecular changes. In conclusion, ACTH administration resulted in a sex-specific onset of depressive-like symptoms and changes in brain regional expression of neurotrophic factors. These results suggest sex-specific mechanisms underlying the development of depressive-like behavior in a model of ACTH-induced HPA axis dysregulation.

A mathematical study of the adrenocorticotropic hormone as a regulator of human gene expression in adrenal glands

Abstract In this research, we have introduced compartments for asymptomatic and symptomatic individuals, along with reduced susceptibility, as key factors defining our investigation. The study is carried out in diverse scenarios, considering them as crucial for the essential generation number of the model, set at 3.18( r 0 &gt; 1 {r}_{0}\gt 1 ). The persistent reproduction differential method was used to explore the impact of continuous adrenocorticotropic hormone (ACTH) administration on the global gene expression in primary cultures of both fetal and adult adrenal cells. The study also investigates ACTH’s genetic effects on both adult and fetal human adrenal cells. The conclusion of this study is demonstrated through relevant and correct medical applications.

Prenatal cortisol exposure impairs adrenal function but not glucose metabolism in adult sheep.

Adverse environmental conditions before birth are known to programme adult metabolic and endocrine phenotypes in several species. However, whether increments in fetal cortisol concentrations of the magnitude commonly seen in these conditions can cause developmental programming remains unknown. Thus, this study investigated the outcome of physiological increases in fetal cortisol concentrations on glucose-insulin dynamics and pituitary-adrenal function in adult sheep. Compared with saline treatment, intravenous fetal cortisol infusion for 5 days in late gestation did not affect birthweight but increased lamb body weight at 1-2 weeks after birth. Adult glucose dynamics, insulin sensitivity and insulin secretion were unaffected by prenatal cortisol overexposure, assessed by glucose tolerance tests, hyperinsulinaemic-euglycaemic clamps and acute insulin administration. In contrast, prenatal cortisol infusion induced adrenal hypo-responsiveness in adulthood with significantly reduced cortisol responses to insulin-induced hypoglycaemia and exogenous adrenocorticotropic hormone (ACTH) administration relative to saline treatment. The area of adrenal cortex expressed as a percentage of the total cross-sectional area of the adult adrenal gland was also lower after prenatal cortisol than saline infusion. In adulthood, basal circulating ACTH but not cortisol concentrations were significantly higher in the cortisol than saline-treated group. The results show that cortisol overexposure before birth programmes pituitary-adrenal development with consequences for adult stress responses. Physiological variations in cortisol concentrations before birth may, therefore, have an important role in determining adult phenotypical diversity and adaptability to environmental challenges.

Effect of Acute and Cumulative Stress on Gene Expression in Mammary Tissue and Their Interactions with Physiological Responses and Milk Yield in Saanen Goats

This study addresses the hypothesis that different acute stressors can cumulatively decrease milk yield. In fact, in a time of global warming, the impact of environmental stress and farm management practices on milk production remains unclear. In this context, our objective was to investigate the effect of acute and cumulative stress on gene expression in mammary tissue and their interactions with physiological responses and milk yield in Saanen goats. Thirty lactating goats were subjected to two treatments: (1) control (CT), in which goats were maintained following a habitual routine under comfort conditions; (2) stress (ST), in which the goats were subjected to different types of environmental stress: heat stress, adrenocorticotropic hormone administration, hoof care management, and exposure to rain. These stressors were performed sequentially, with one stress per day on four consecutive lactation days, to evaluate their effect on milk quality and milk yield. Our results showed that compared to CT goats, cumulative stress increased the gene expression of glucocorticoid receptor (GR), interferon-gamma (IFN-γ), superoxide dismutase (SOD), and catalase (CAT) in mammary tissue, which are indicators of cortisol action, inflammatory response, and antioxidant enzymes. Furthermore, the acute challenges imposed on ST goats changed their rectal temperature and respiratory frequency and increased cortisol, glucose, cholesterol, triglycerides, and high-density lipoprotein release in plasma when compared to CT goats. Although these physiological and metabolic responses restore homeostasis, ST goats showed lower milk yield and higher somatic cell count in milk than CT goats. In conclusion, the results confirmed our initial hypothesis that different acute stressors cumulatively decrease the milk yield in Saanen goats.

Trends in Immunosuppressive Agent Use for Non-Infectious Uveitis by US Ophthalmologists in Medicare Beneficiaries and Association with Physician–Industry Interactions

ABSTRACT Purpose To report the trends of immunosuppressive drug use for non-infectious uveitis and explore their relationship with industry payments. Methods A retrospective review of ophthalmologists reimbursed by Medicare for the administration of adalimumab (ADA), repository corticotropin (RCI), methotrexate (MTX), and mycophenolate mofetil (MMF) between 2014 and 2018. Results A total of 316 ophthalmologists were reimbursed by Medicare for 1567 ADA, 465 RCI, 1752 MTX, and 12 333 MMF administrations. The number and dollar amount of industry payments were positively associated with ADA and RCI use (P < 0.001). From 2014 to 2018, there was a positive trend in the proportion of ADA (P = 0.007) and RCI (P = 0.007) used and negative trend in the proportion of MMF (P = 0.025) used. Conclusion From 2014 to 2018, the use of ADA and RCI increased while MMF decreased and MTX remained stable. There was a positive association between ADA and RCI use and physician–industry interactions. A causal relationship is not determined.

Identification of Potential miRNA Biomarkers to Detect Hydrocortisone Administration in Horses.

Circulating microRNAs (miRNAs) are stable in bodily fluids and are potential biomarkers of various diseases and physiological states. Although several studies have been conducted on humans to detect drug doping by miRNAs, research on drugs and miRNAs in horses is limited. In this study, circulating miRNAs in horses after hydrocortisone administration were profiled and variations in miRNAs affected by hydrocortisone administration during endogenous hydrocortisone elevation were examined. The miRNAs were extracted from thoroughbred horse plasma before and after hydrocortisone administration and subjected to small RNA sequencing and reverse transcription quantitative PCR (RT-qPCR). RT-qPCR validation was performed for the 20 miRNAs that were most affected by hydrocortisone administration. The effects of elevated endogenous hydrocortisone levels due to exercise and adrenocorticotropic hormone administration were also confirmed. The validation results showed that approximately half of the miRNAs showed the same significant differences as those obtained using small RNA sequencing. Among the twenty miRNAs, two novel miRNAs and miR-133a were found to vary differently between exogenous hydrocortisone administration and endogenous hydrocortisone elevation. This study provides basic knowledge regarding the circulating miRNA profile of horses after hydrocortisone administration and identifies three miRNAs that could potentially be used as biomarkers to detect hydrocortisone administration.

The Reliability of Salivary Cortisol Compared to Serum Cortisol for Diagnosing Adrenal Insufficiency with the Gold Standard ACTH Stimulation Test in Children.

The ACTH (adrenocorticotropic hormone) stimulation test is the gold standard for the diagnosis of adrenal insufficiency (AI), performed with ACTH high dose (HDT) or low dose (LDT). As salivary cortisol has been proposed as an alternative to serum cortisol, our aim was to evaluate the reliability of salivary cortisol compared to serum cortisol for diagnosing AI in children. Data were collected retrospectively. Salivary and serum cortisol values derived by 80 ACTH stimulation tests were obtained (39 F, 36 M; median age 11.5 years, IQR 6.9). Sampling was performed at baseline and after 30 and 60 min from ACTH administration during the HDT, and at baseline and 10, 20, 30, 40 and 60 min after the stimulation for the LDT. A serum cortisol level > 420 nmol/L ruled out AI. The correlation coefficients between serum and salivary cortisol for the HDT (n = 24) were 0.80 at t0, 0.48 at t30 and 0.75 at t60. All patients were adrenal sufficient. In 41% of the LDT, peak serum cortisol indicated insufficient adrenal function. The correlation coefficients between serum and salivary cortisol were 0.59 at t0 and 0.33 at the peak. For a cut-off of salivary cortisol < 15 nmol/L, sensitivity was 73.9% and specificity 69.6%. Our data do not support salivary cortisol as a valid alternative to serum cortisol during LDT. Regarding the HDT, results are more encouraging, however, further studies are needed.

The “Blast” Behind Jerky Eyes

AbstractOpsoclonus is defined as hyperkinetic, omnidirectional, spontaneous, and involuntary chaotic eye movements. Opsoclonus-myoclonus-ataxia syndrome is addressed by many names including “dancing eyes-dancing feet syndrome,” “Kinsbourne syndrome,” and “infantile polymyoclonia.” The early accounts of the clinical syndrome date back to 1962 when Marcel Kinsbourne described six cases of this phenotype. However, it was not until 1968 the association with occult neuroblastoma was first reported. We report the video of a 1-year-old boy who presented with this syndrome for a duration of 3 months. He was diagnosed to have an abdominal neuroblastoma and was treated with resection of the tumor and administration of intramuscular adrenocorticotropic hormone. He showed complete resolution of symptoms. The syndrome is difficult to recognize and might be confused with seizures, tremors, or chorea; hence, it is important that residents learnt to recognize this syndrome and look for an underlying tumor actively.

Fish Scales Produce Cortisol upon Stimulation with ACTH.

Cortisol concentration in fish scales is a novel and reliable indicator of chronic stress. However, until now cortisol in scales has been considered to be accumulated through the circulation and it has not yet been studied whether it can be de novo produced from cells found in the scales. In the current study, scales of European sea bass, Dicentrarchus labrax, were stimulated in-vitro with a range of concentrations of adrenocorticotropic hormone (ACTH) to investigate if they can produce and release cortisol. Moreover, scales were exposed to a combination of ACTH and metyrapone, an inhibitor of cortisol production, to examine whether cortisol was actually produced in the scales. Results from ACTH administration showed that scales increased their cortisol release in a dose-dependent manner. This effect was reversed when scales were co-incubated with ACTH and metyrapone, indicating that cortisol was produced de novo and not released only upon stimulation with ACTH.

Partial Efficacy of Vigabatrin in an Infant With West Syndrome Due to Pyruvate Dehydrogenase Complex Deficiency: A Case Report

Pyruvate dehydrogenase complex (PDHC) deficiency is a metabolic disease associated with lactic acidosis, and mutation in PDHA1 is the major cause.1,2 The incidence rate of West syndrome among patients with PDHC deficiency was reported as 17%.3 Previous studies reported the clinical experience of antiepileptic therapies, including ketogenic diet and/or administration of vitamin B1, B6, sodium dichloroacetate, adrenocorticotropic hormone, zonisamide, valproic acid, and vigabatrin; however, few studies demonstrated the effectiveness of these treatments.

ODP047 Intramuscular ACTH stimulation test in a patient with liver disease

Abstract Introduction High dose (250 mcg) ACTH stimulation test is the gold standard dynamic testing to diagnose primary adrenal insufficiency (PAI). While the current guidelines do not elaborate on the preferable route of administration of corticotropin (intravenous or intramuscular), most published studies have been conducted on healthy people using the intravenous route. We present a patient with non-alcoholic steatohepatitis cirrhosis and hypotension who was thought to have suboptimal response with intramuscular ACTH stimulation test. Case 62-year-old male with cirrhosis, presented with dizziness, and was found to be hypotensive. Lab tests showed normal cell counts, electrolytes, renal function and lactic acid. His albumin was 2.6 g/dL. His blood pressure did not improve with intravenous fluids. Workup initiated for adrenal insufficiency showed 8 am cortisol level of 7. 0 mcg/dL, and ACTH level of 26 pg/mL. He underwent ACTH stimulation test with 250 mcg intramuscular cosyntropin, after which the 30-minute cortisol level was 13.7 mcg/dL and the 60-minute level was 15.1 mcg/dL (level immediately before the test 7.2 mcg/dL). Due to the patient not having signs of adrenal insufficiency and low albumin level due to liver disease, the cortisol response was considered adequate. Discussion Per the current Endocrine Society Clinical Practice Guidelines, the standard method of performing the ACTH stimulation test involves measuring baseline cortisol level, administration of 250 mcg of cosyntropin, and then measuring cortisol level 30 and 60 minutes post administration. Traditionally, an appropriate response is characterized by peak cortisol level above 18 mcg/dL, with lower values indicative of AI. While the responses can vary due to multitude of factors including time of testing etc., the individual response to the intravenous versus intramuscular injections is similar. However, the cut-off points between the two administration methods may differ. In a study on 64 healthy adult men who were administered 250 mcg cosyntropin intramuscularly, Longui et al. demonstrated lower cut-off values of 12.6 mcg/dL and 16.3 mcg/dL at 30 and 60 minutes respectively. In addition, with the introduction of newer monoclonal antibody and LC-MS/MS assays having greater specificity for cortisol, a study by Jarvosky et. al. recommends a new lower cut-off of 14-15 mcg/dL. Furthermore, several studies have shown higher prevalence of low total cortisol levels in cirrhosis and other liver disease leading to overdiagnosis of PAI, due to deficiency of cortisol binding globulin and albumin. In our patient, we hypothesize that the combination of all these factors could have caused a falsely low cortisol peak level without any underlying PAI. Our case highlights the need for additional studies on patients with underlying liver disease and hypoalbuminemia who undergo testing with intramuscular cosyntropin administration, and analysis with the new assays available. Presentation: No date and time listed

Differential regulation of gene expression pathways with dexamethasone and ACTH after early life seizures

Early-life seizures (ELS) are associated with persistent cognitive deficits such as ADHD and memory impairment. These co-morbidities have a dramatic negative impact on the quality of life of patients. Therapies that improve cognitive outcomes have enormous potential to improve patients' quality of life. Our previous work in a rat flurothyl-induction model showed that administration of adrenocorticotropic hormone (ACTH) at time of seizure induction led to improved learning and memory in the animals despite no effect on seizure latency or duration. Administration of dexamethasone (Dex), a corticosteroid, did not have the same positive effect on learning and memory and has even been shown to exacerbate injury in a rat model of temporal lobe epilepsy. We hypothesized that ACTH exerted positive effects on cognitive outcomes through beneficial changes to gene expression and proposed that administration of ACTH at seizure induction would return gene-expression in the brain towards the normal pattern of expression in the Control animals whereas Dex would not. Twenty-six Sprague-Dawley rats were randomized into vehicle- Control, and ACTH-, Dex-, and vehicle- ELS. Rat pups were subjected to 60 flurothyl seizures from P5 to P14. After seizure induction, brains were removed and the hippocampus and PFC were dissected, RNA was extracted and sequenced, and differential expression analysis was performed using generalized estimating equations. Differential expression analysis showed that ACTH pushes gene expression in the brain back to a more normal state of expression through enrichment of pathways involved in supporting homeostatic balance and down-regulating pathways that might contribute to excitotoxic cell-damage post-ELS.

Differences in thyroid function tests after administration of a single supraphysiological dose of ACTH or a high dose of a synthetic steroid

ObjectiveAlthough the suppressive action of synthetic steroids on the hypothalamus-pituitary-thyroid (HPT) axis is established, little is known regarding the effect of the administration of synthetic adrenocorticotropic hormone (ACTH). DesignIn the context of a randomized, open label, comparative study assessing the efficacy and safety of ACTH and betamethasone in the treatment of hospitalized patients with acute gout, we compared the effects of these agents on thyroid function tests. MethodsSerum TSH, total T4 and T3 and cortisol were measured before and at 24 and 48 h after a single intramuscular dose of synthetic ACTH (1 mg) or betamethasone (6 mg), in 38 hospitalized patients with acute gout and normal thyroid function. ResultsThe final analysis included 32 patients, due to missing data. The ACTH and betamethasone groups did not differ regarding the mean age, gender, severity of gout attack, and baseline thyroid parameters. In the ACTH group TSH and T4 were significantly decreased at 24 and at 48 h compared to baseline, while T3 was decreased at 24 but not at 48 h. In the betamethasone group T3 remained stable; TSH and T4 decreased significantly from baseline levels at 24 h; at 48 h, TSH had returned to and T4 showed a partial rebound towards pre-treatment values. ConclusionsA single IM administration of 1 mg of synthetic ACTH has more profound and prolonged effects on the HPT axis, lasting for at least 48 h, compared to a single IM dose of 6 mg betamethasone.

Effects of Galp and alarin peptides on HPA axis gene expression and adrenal function: In vivo experiments.

Many experimental data indicate interactions between peptides involved in the control of food intake, energy homeostasis and adrenocortical hormone release. Glucocorticoids stimulate or inhibit the secretion of orexigenic and anorexigenic peptides, which in turn are involved in the regulation of adrenal growth, structure and function. Galanin-like peptide (Galp) and alarin (Ala) are involved in the regulation of food intake. Galp and Ala mRNAs have already been shown to be present in the arcuate nucleus (ARC) of the hypothalamus in both rats and mice. To investigate the expression of Ala, Galp and their receptors in the hypothalamus and pituitary and adrenal glands of the rat hypothalamic-pituitary-adrenal (HPA) axis after intraperitoneal administration of peptides in vivo. Experimental in vivo models were used: acute and long-term exposure to peptides. The expression of Galp, Ala, their receptors, and steroidogenesis enzymes was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). Statistically significant expression changes were found in the hypothalamus and pituitary after 1-hour exposure to the peptides, such as a decrease in corticotropin-releasing hormone (CRH) expression after Ala, Galp and adrenocorticotropic hormone (ACTH) administration, and a decrease in the expression of receptors for galanin (Gal) (Galr1 and Galr2). In the pituitary, there was a statistically significant increase in the expression of Ala, Galr1, Galr2, and Galr3 receptors 1 h after Galp administration. In the adrenal glands, only a statistically significant decrease in Galr2 expression was observed after 1 h of Ala 0.5 administration. The mRNA expression of steroidogenesis enzymes also changed: for example, the expression of cholesterol desmolase increased 24 h after Ala peptide administration. The results indicate that the peptides tested under in vivo conditions can alter the expression of the peptides tested, as well as of Galp, Ala and Gal receptors and steroidogenesis enzymes - Cyp11a1 (cholesterol desmolase), Cyp11b1 (11β-hydroxylase) and Cyp11b2 (aldosterone synthase).

Adrenal Venous Sampling for Subtype Diagnosis of Primary Hyperaldosteronism.

Adrenal venous sampling (AVS) is the key procedure for lateralization of primary hyperaldosteronism (PA) before surgery. Identification of the adrenal veins using computed tomography (CT) and intraoperative cortisol assay facilitates the success of catheterization. Although administration of adrenocorticotropic hormone (ACTH) has benefits such as improving the success rate, some unilateral cases could be falsely diagnosed as bilateral. Selectivity index of 5 with ACTH stimulation to assess the selectivity of catheterization and lateralization index (LI) >4 with ACTH stimulation for unilateral diagnosis is used in many centers. Co-secretion of cortisol from the tumor potentially affects the lateralization by the LI. Patients aged <35 years with hypokalemia, marked aldosterone excess, and unilateral adrenal nodule on CT have a higher probability of unilateral disease. Patients with normokalemia, mild aldosterone excess, and no adrenal tumor on CT have a higher probability of bilateral disease. Although no methods have 100% specificity for subtype diagnosis that would allow bypassing AVS, prediction of the subtype should be considered when recommending AVS to patients. Methodological standardization and strict indication improve diagnostic quality of AVS. Development of non-invasive imaging and biochemical markers will drive a paradigm shift in the clinical practice of PA.

Solumedrol Treatment for Severe Sepsis in Humans with a Blunted Adrenocorticotropic Hormone-Cortisol Response: A Prospective Randomized Double-Blind Placebo-Controlled Pilot Clinical Trial

To test the benefits of Solumedrol treatment in sepsis patients with a blunted adrenocorticotropic hormone (ACTH)-cortisol response (delta <13 µg/dL) with regard to the number of days on ventilator, days on intravenous blood pressure support, length of time in an intensive care unit (ICU), 14-day mortality, and 28-day mortality. The trial was prospective, randomized, and double-blind. As part of a larger sepsis trial, 54 patients with sepsis had an intravenous ACTH stimulation test using 250 µg of ACTH, and serum cortisol was measured at times 0, 30, and 60 min. Eleven patients failed to increase their cortisol concentration above 19.9 µg/dL and were excluded from the clinical trial as they were considered to have adrenal insufficiency. The remaining 43 patients had a baseline cortisol of 32 ± 1 µg/dL increased to 38 ± 3 µg/dL at 30 min and 40 ± 3 at 60 min. All cortisol responses were <12.9 µg/dL between time 0 and time 60, which is defined as a blunted cortisol response to intravenous ACTH administration. Twenty-one were randomized to receive 20 mg of intravenous Solumedrol and 22 were randomized to receive a matching placebo every 8 h for 7-days. There was no significant difference between the two randomized groups. Data analysis was carried out bya two-tailed test and P < .05 as significant. The mean age was 51 ± 2 (mean ± SEM) with 61% female. Groups were well matched with regard to APACHE III score in Solumedrol versus placebo (59 ± 6 vs 59 ± 6), white blood cell count (18.8 ± 2.2 vs 18.6 ± 2.6), and incidence of bacteremia (29 vs 39%). The 28-day mortality rate was reduced in the Solumedrol treated arm (43 ± 11 vs 73 ± 10%; P < .05). There was no change in days in ICU, days on blood pressure agents, or days on ventilator. Seven days of high-dose intravenous Solumedrol treatment (20 mg every 8 h) in patients with a blunted cortisol response to ACTH was associated with an improved 28-day survival. This small study suggests that an inability to increase endogenous cortisol production in patients with sepsis who are then provided steroid treatment could improve survival.

ACTH treatment promotes murine cardiac allograft acceptance.

Heart transplantation is the optimal therapy for patients with end-stage heart disease, but its long-term outcome remains inadequate. Recent studies have highlighted the importance of the melanocortin receptors (MCRs) in inflammation, but how MCRs regulate the balance between alloreactive T cells and Tregs, and whether they impact chronic heart transplant rejection, is unknown. Here, we found that Tregs express MC2R, and MC2R expression was highest among all MCRs by Tregs. Our data indicate that adrenocorticotropic hormone (ACTH), the sole ligand for MC2R, promoted the formation of Tregs by increasing the expression of IL-2Rα (CD25) in CD4+ T cells and activation of STAT5 in CD4+CD25+ T cells. ACTH treatment also improved the survival of heart allografts and increased the formation of Tregs in CD28KO mice. ACTH treatment synergized with the tolerogenic effect of CTLA-4–Ig, resulting in long-term survival of heart allografts and an increase in intragraft Tregs. ACTH administration also demonstrated higher prolongation of heart allograft survival in transgenic mouse recipients with both complete KO and conditional KO of PI3Kγ in T cells. Finally, ACTH treatment reduced chronic rejection markedly. These data demonstrate that ACTH treatment improved heart transplant outcomes, and this effect correlated with an increase in Tregs.

Evaluation of Adrenal Cortical Function in Neonatal and Weanling Laboratory Beagle Dogs.

The most common target organ for toxicity in the endocrine system is the adrenal gland, and its function is dependent upon the hypothalamus and pituitary gland. Histopathologic examination of the adrenal glands and pituitary gland is routinely performed in toxicity studies. However, the function of the adrenal gland is not routinely assessed in toxicity studies. Assessment of adrenal cortical function may be necessary to determine whether a histopathologic finding in the adrenal cortex results in a functional effect in the test species. As juvenile toxicity studies are more commonly performed in support of pediatric indications for pharmaceuticals, it is important to establish historical control data for adrenal gland function. In this study, adrenal cortical function was assessed in control neonatal and weanling beagle dogs as part of an ongoing juvenile toxicology program. Measurements of serum adrenocorticotropic hormone (ACTH), cortisol prior to and following administration of exogenous ACTH, and aldosterone were conducted beginning at 2 weeks of age continuing through 26 weeks of age. Serum electrolyte concentrations were determined at 4, 13, and 26 weeks of age. Dogs as young as 2 weeks of age synthesize and secrete adrenal cortical hormones and exhibit a functional hypothalamic pituitary adrenal axis.

Decisive evidence of direct effect of ACTH treatment in West syndrome: A case report

In patients with West syndrome, the administration of exogenous adrenocorticotropic hormone (ACTH) is considered a potent and effective treatment [1]. Exogenously administered ACTH hyperactivates the hypothalamic-pituitary-adrenal axis (Fig. 1A); however, the resulting hormonal changes cannot fully account for the therapeutic effect of ACTH. Indeed, the administration of corticosteroids to patients with West syndrome failed to provide an anti-epileptic effect comparable to that of ACTH [1]. Thus, the antiepileptic effect of ACTH in West syndrome has been postulated to involve a direct action of ACTH on the central nervous system (i.e., a “direct pathway”) that occurs independently of the hypothalamic-pituitary-adrenal axis (i.e., an “indirect pathway”).

Effects of CRN04894, a Nonpeptide Orally Bioavailable ACTH Antagonist, on Corticosterone in Rodent Models of ACTH Excess

CRN04894 is an orally administered nonpeptide that is a potent and selective antagonist for adrenocorticotropic hormone (ACTH) acting at the melanocortin 2 receptor (MC2R) and is currently under development for the treatment of diseases of ACTH excess such as Cushing’s disease, congenital adrenal hyperplasia, and ectopic ACTH-secreting tumors. Cushing’s disease results from an adenoma derived from pituitary corticotropic cells that secrete excess ACTH, whereas ectopic ACTH syndrome arises from nonpituitary ACTH secreting tumors. Congenital adrenal hyperplasia is a genetic disease that results in cortisol deficiency leading to high levels of ACTH and adrenal androgens. Each of these indications is characterized by high ACTH levels that act on MC2R expressed in the adrenal cortex to drive pathological elevations of adrenally derived steroid hormones. CRN04894 blocks the action of ACTH at MC2R, providing a potential novel treatment for these diseases. Preclinical models of chronic hypercortisolemia include implantation of ACTH-secreting pituitary tumor cells in mice and continuous administration of ACTH via subcutaneously implanted osmotic pumps in rats. These models induce features consistent with human diseases of ACTH excess including hypercortisolemia and hypertrophy of the adrenal glands. We employed both rodent models to examine the pharmacodynamic effects of CRN04894 on corticosterone levels and adrenal gland morphology. In the mouse pituitary tumor model, subcutaneous inoculation of the ACTH-secreting mouse pituitary tumor cell line, AtT-20, into immunodeficient mice resulted in formation of tumors and increased plasma ACTH and corticosterone levels. Repeated daily oral administration of CRN04894 for 14 days dose-dependently and robustly suppressed plasma corticosterone levels in mice with AtT-20 tumors. In the rat model, subcutaneous implantation of osmotic pumps delivering ACTH resulted in increased corticosterone levels, reduction in body weight, and hypertrophy of the adrenal glands after 7 days. Daily oral administration of CRN04894 over 7 days dose-dependently suppressed corticosterone levels, mitigated the effect of ACTH excess on body weight, and rescued the adrenal gland hypertrophy. These findings provide evidence that CRN04894 functions as an effective ACTH antagonist at MC2R to suppress adrenal corticosterone secretion in both mouse and rat models of ACTH excess and hypercortisolemia, thus providing a strong rationale for its potential therapeutic utility in diseases of ACTH excess. This work was supported in part by an SBIR grant from the NIH awarded to Dr. Struthers (R43- DK115245)