Results of a 5-Year N-of-1 Growth Hormone Releasing Hormone Gene Therapy Experiment.

Here presented for the first time are results showing persistence over a 5+ year period in a human who had a hormone gene therapy administered to muscle. This growth hormone releasing hormone (GHRH) therapy was administered in two doses, a year apart, with a mean after the second dose of 195 ng/mL (13 × normal, σ = 143, σM = 34, max = 495, min = 53). This level of GHRH therapy appears to be safe for the subject, although there were some adverse events. Insulin-like growth factor 1 levels were little affected, nor were the growth hormone test results, showing no indications of acromegaly for the hormone homologue used. Heart rate declined 8 to 13 bpm, persistent over 5 years. Testosterone rose by 52% (σ = 22%, σM = 6%). The high-density lipoprotein/low-density lipoprotein ratio dropped from 3.61 to mean 2.81 (σ = 0.26, σM = 0.057, max = 3.3, min = 2.5), and triglycerides declined from 196 mg/dL to mean 94.4 mg/dL (σ = 21.9, σM = 5.0, min = 59, max = 133, min = 59). White blood cell counts increased, however, the baseline was not strong. CD4 and CD8 mean increased by11.7% (σ = 11.6%, σM = 3.3%, max = 30.7%, min = -9.6%) and 12.0% (σ = 10.5%, σM = 3.0%, max = 29.1%, min = -6.7%), respectively. Ancillary observations comprise an early period of euphoria, and a dramatic improvement in visual correction after the first dose, spherical correction from baseline (L/R) -2.25/-2.75 to -0.25/-0.5. Over the next 5 years, correction drifted back to -1.25/-1.75. Horvath PhenoAge was cut 44.1% post-treatment. At completion, epigenetic age was -6 years (-9.3%), and telomere age was +7 months (+0.9%).

GHRH expression plasmid improves osteoporosis and skin damage in aged mice.

The hormone secretion of GHRH-GH-IGF-1 axis in animals was decreased as aging. These hormones play an important role in maintaining bone mass and bone structure, and also affect the normal structure and function of the skin. We used plasmid-based technology to deliver growth hormone releasing hormone (GHRH) to elderly mice. In the current study, 80 and 120 µg/kg pVAX-GHRH plasmid expression plasmid were injected into old mice, the serum GHRH and insulin-like growth factor-1(IGF-1) content were increased within three weeks (P < 0.05). In the groups of 80 and 120 µg/kg plasmid, the content of procollagen type I N-terminal pro-peptide (PINP) in the serum was increased(P < 0.05), and the content of C-terminal telopeptides of type I collagen (CTX-1) in the serum was reduced significantly (P < 0.05). Furthermore, the expression of osteoprotegerin (OPG) and osteocalcin (OCN) in the femur also was increased(P < 0.05). The bone mineral density(BMD)、trabecular bone volume (BV/TV) and trabecular number(Tb.N) of mouse femur were increased significantly (P < 0.05) and trabecular separation(Tb.Sp) was decreased(P < 0.05). There were more trabecular bones in the bone marrow cavity and the trabecular bones are thicker in the groups of 80 and 120 µg/kg plasmid relative to control. The superoxide dismutase (SOD) content in the skin was increased(P < 0.05), and the malondialdehyde (MDA) content was reduced significantly (P < 0.05). Meanwhile, the skin moisture content also increased significantly(P < 0.05). Moreover, the expression of matrix metalloproteinase 3(MMP3) and matrix metalloproteinase 9(MMP9) was decreased in the skin(P < 0.05). The thickness of the dermis and epidermis of the skin had increased significantly(P < 0.05). Skin structure is more dense and complete in the two groups. These results indicate that 80 and 120 µg/kg plasmid-mediated GHRH supplementation can improve osteoporosis and skin aging in aged mice.

Glucagon stimulation test to assess growth hormone status in Prader-Willi syndrome.

PURPOSE: Growth hormone deficiency (GHD) must be confirmed before starting treatment in adults with Prader-Willi syndrome (PWS). Most studies use the growth-hormone-releasing hormone plus arginine (GHRH-arginine) test. No data are available on the glucagon stimulation test (GST) in PWS. We compared the utility of fixed-dose (1 mg) GST versus GHRH-arginine test in diagnosing GHD. METHODS: Adults and late adolescents with PWS underwent both tests on separate days. In the GHRH-arginine test, GHD was defined according to body mass index. In the GST, two cutoffs were analyzed: peak GH concentration < 3 ng/mL and < 1 ng/mL. For analyses, patients were divided into two groups according to body weight (≤ 90 kg and > 90 kg). RESULTS: We analyzed 34 patients: 22 weighing ≤ 90 kg and 12 weighing > 90 kg. In patients weighing ≤ 90 kg, the two tests were concordant in 16 (72.72%) patients (k = 0.476, p = 0.009 with GST cutoff < 3 ng/mL, and k = 0.450, p = 0.035 with GST cutoff < 1 ng/mL). In patients weighing > 90 kg, the two tests were not concordant with GST cutoff < 3 ng/mL, but were concordant in 11 (91.6%) patients (k = 0.833, p = 0.003) with GST cutoff < 1 ng/mL. GH peaks on the two tests correlated (r = 0.725, p = 0.008). CONCLUSION: Fixed-dose (1 mg) GST using a peak GH cutoff of < 3 ng/mL or < 1 ng/mL promises to be useful for screening for GHD in adults and late adolescents with PWS. However, in those weighing > 90 kg, the < 1 ng/mL cutoff seems better. Larger studies are necessary to establish definitive glucagon doses and cutoffs, especially in extremely obese patients.

Immune dyscrasia in adult growth hormone deficiency: Evaluation of hemolytic complement activity (CH50) and IgG subclasses.

CH50 is a screening assay for the activation of the classical complement pathway, the immunoglobulins-mediated one, activated in several inflammatory diseases. Adult growth hormone deficiency (aGHD) is recognized as a chronic inflammatory condition, although poorly evaluated under the profile of inflammatory biomarkers. The aim of this case-control observational study is to analyze CH50 and immunoglobulins G (IgG) subclasses production in aGHD, comparing this condition to healthy controls. 38 subjects were included and divided as follows: aGHD (n = 18, 6 females and 12 males); healthy controls (n = 20, 10 females and 10 males). GHD was diagnosed with dynamic test using Growth Hormone-Releasing Hormone (GHRH 50 µg i.v. + arginine 0,5 g/Kg), with a peak GH response < 9 µg/L when BMI was <30 kg/m2 or < 4 µg/L when BMI was >30 kg/m2. The two groups were evaluated for hormonal and metabolic parameters, CH50 and IgG subtypes. IgG1 and IgG2 were significantly higher in controls than in aGHD, while IgG3 and IgG4 showed a trend to higher levels in controls, although not significant. Furthermore, CH50 levels were significantly higher in aGHD. These data substantiate the hypothesis of a dyscrasia in IgG subclasses production in aGHD. As IgG levels decrease, CH50 levels do not.

The intra-individual stability of GH biomarkers IGF-I and P-III-NP in relation to GHRH administration, menstrual cycle, and hematological parameters.

The intra-individual stability of growth hormone (GH) biomarkers IGF-I, P-III-NP, calculated GH-2000 score in relation to growth hormone-releasing hormone (GHRH) (Somatorelin) administration, menstrual cycle, and hematological parameters were investigated in four men and eight women, respectively. Moreover, the hematological parameters hemoglobin (Hb) and percentage of reticulocyte (RET%) were statistically analyzed in relation to the GH biomarker parameters for the GHRH administration study and the menstrual cycle study. Longitudinal monitoring of IGF-I and/or GH-2000 score proved to be a viable approach to detect the GHRH intake in men, as all four participants show values above individually calculated thresholds (calculated as mean ± 3SD from three baseline samples). The intra-individual variation for IGF-I, P-III-NP, and calculated GH-2000 score in women, over two consecutive menstrual cycles, was investigated and established to be higher (coefficients variations [CVs] between 12% and 186%) than in men (CVs between 3% and 12%). The GHRH administration did not influence the hematological parameters. A strong positive correlation between Hb and IGF-I (Rs = 0.73, p < 0.0001) and a borderline weak correlation between RET% and IGF-I (Rs = 0.28, p = 0.054) were noticed in the women. No correlation for the P-III-NP and the hematological parameters was seen for the females in the menstrual cycle study. The results fortify previous studies that longitudinal monitoring of IGF-I and/or GH-2000 score may be a promising method to detect doping with GH and GH stimulating agents in men, whereas the large intra-individual variation noted in women indicates that longitudinal monitoring of these biomarker may be harder to evaluate in women.

Growth Hormone (GH) Therapy During the Transition Period: Should We Think About Early Retesting in Patients with Idiopathic and Isolated GH Deficiency?

To investigate growth hormone (GH) secretion at the transition age, retesting of all subjects who have undergone GH replacement therapy is recommended when linear growth and pubertal development are complete to distinguish between transitional and persistent GH deficiency (GHD). Early retesting of children with idiopathic and isolated GHD (i.e., before the achievement of final height and/or the adult pubertal stage) can avoid possible over-treatment. Here, we report data from our population with idiopathic and isolated GHD to encourage changes in the management and timing of retesting. We recruited 31 patients (19 males) with idiopathic GHD who received recombinant GH (rGH) for at least 2 years. All of the patients were retested at the transition age at least 3 months after rGH discontinuation. Permanent GHD was defined as a GH peak of <19 ng/mL after administration of growth hormone⁻releasing hormone (GHRH) + arginine as a provocative test. Permanent GHD was confirmed in only five of 31 patients (16.13%). None of these patients presented low serum insulin-like growth factor (IGF)-1 levels (<-2 standard deviation score (SDS)). Only one male patient with an IGF-1 serum level lower than -2 SDS showed a normal GH stimulation response, with a GH peak of 44.99 ng/mL. Few patients with idiopathic and isolated GHD demonstrated persistence of the deficit when retested at the transition age, suggesting that the timing of retesting should be anticipated to avoid overtreatment.

IGF-1 and somatocrinin trigger islet differentiation in human amniotic membrane derived mesenchymal stem cells.

AIM: To induce differentiation of human amniotic membrane derived mesenchymal stem cells (hAMMSCs) into insulin producing cells (IPCs) by treating with somatocrinin or growth hormone releasing hormone (GHRH) and Insulin-like growth factor-1 (IGF-1). MAIN METHOD: In this investigation, we cultivated and characterized hAMMSCs and then treated with IGF-1 and somatocrinin to find out whether this combination gives better yield of insulin producing cells. We showed that hAMMSCs can give rise to IPCs on exposure to serum-free defined media containing specific growth factors and differentiating agents in presence of IGF-1 and somatocrinin. KEY FINDING: A combination of IGF-1 and somatocrinin lead to differentiation of large number of IPCs from hAMMSCs. These IPCs were found to be positive for dithizone indicating their insulin secretory mechanism. Moreover these cells were also found to be positive for C-peptide. IPCs released insulin in response to glucose challenge. Gene expression analysis exhibited significant up-regulation of pancreatic transcription factor GLUT2 and Insulin. SIGNIFICANCE: Our data thus demonstrates for the first time that somatocrinin and IGF-1 synergistically enhance the differentiation of hAMMSCs into IPCs.

An immuno polymerase chain reaction screen for the detection of CJC-1295 and other growth-hormone-releasing hormone analogs in equine plasma.

CJC-1295 is a 30 amino acid peptide-based drug that stimulates the release of growth hormone (GH) from the pituitary gland. It is unique among performance-enhancing peptides due to the presence of a reactive maleimidopropionic acid group that covalently links the peptide to free thiols on the surface of plasma proteins. Once conjugated, CJC-1295 remains active in the bloodstream for significantly longer than non-conjugated peptide-based drugs that are rapidly excreted. Conjugation of CJC-1295 to plasma proteins prevents its detection by top-down mass-spectrometry-based peptide screening protocols as it effectively becomes a macromolecular protein with an undefined molecular weight. Using a pair of monoclonal antibodies raised against the CJC-1295 peptide, we present an immuno-polymerase chain reaction (I-PCR) assay that is capable of detecting the CJC-1295-protein conjugate at concentrations down to 0.8 pg/mL. Detection of endogenous equine GHRH necessitated a screening threshold for CJC-1295 in equine plasma of 50 pg/mL. The effectiveness of the assay for controlling the illicit use of CJC-1295 was confirmed in equine blood samples after administration in thoroughbred race horses.

Aromatized Estrogens Amplify Nocturnal Growth Hormone Secretion in Testosterone-Replaced Older Hypogonadal Men.

Context: Testosterone (T) increases GH secretion in older men with a relative lack of T, in hypogonadal men of all ages, and in patients undergoing sex reassignment. The role of estradiol (E2) in men is less well defined. Objective: To assess the contribution of aromatization of T to spontaneous nocturnal and stimulated GH secretion. Participants: Four groups of healthy older men (N = 74, age range 57 to 77 years) were studied. The gonadotropic axis was clamped with the gonadotropin-releasing hormone antagonist degarelix. Three groups received T and one group placebo addback. Two T-replaced groups were treated with anastrozole (an aromatase inhibitor) and either placebo or E2 addback. Main Outcome Measures: Ten-minute GH concentration profiles were quantified by deconvolution analysis, after overnight (2200 to 0800 hours) sampling, and after combined IV injection of GHRH (0.3 µg/kg) and GHRH-2 (0.3 µg/kg) and withdrawal of a 2-hour somatostatin infusion (1 µg/kg/h). Results: E2 addback during aromatase inhibition increased basal (P = 0.046), pulsatile (P = 0.020), and total (P = 0.018) GH secretion by 60% to 70%. E2 did not potentiate GH secretory stimuli. Logarithmically transformed pulsatile GH secretion correlated strongly and positively with concurrent E2 concentrations overall (P = 0.028) and under anastrozole treatment (P = 0.005). Conclusion: E2 administration in older men transdermally stimulates overnight pulsatile GH secretion. The exact site of E2 action cannot be ascertained from these experiments but may include hypothalamic loci involved in GH regulation, especially because GH secretagogue effects on somatotrope pituitary cells were not affected.

Novel hGHRH homodimer promotes fertility of female infertile hamster by up-regulating ovarian GHRH receptor without triggering GH secretion.

Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in infertility. The female infertility models were formed by intraperitoneally injecting cyclophosphamide in 5-week-old Chinese hamster once in a week for 5 weeks. All the models mated with healthy male hamster in the ratio of 1:1 in the experimental 6-8th week and the couples were separated to breed in the 9-10th week. 20 mg/kg of cyclophosphamide induced temporary interference of reproduction and did not cause significant difference in the weight of body, bilateral ovaries, or liver. By intramuscularly injecting twice in a week during the experimental 4-10th week, 2, 4, 8 mg/kg of Grin induced 30, 42.9, 60% of total pregnancy rates in a dose-dependent manner whereas 200 U/kg of hMG induced 50% of total pregnancy rates. The single cyclophosphamide dose caused strongly eosinophilic ovarian cells, scattered early follicles, many atretic follicles, and no corpora luteum was observed. The hMG group individually presents many follicles at all levels, especially secondary ones in the ovarian cortex and medulla. Much of loose connective tissue, vacuoles, and sparse interstitial cells distribute in the medulla. Grin induced many follicles at all dose levels and corpora lutea in the cortex, and the compactly aligned interstitial cells occurred in the whole ovarian tissue. The less TUNEL staining and higher expression of ki67 showed the proliferation and protection effect of Grin on ovarian cells. Grin obviously promotes fertility by up-regulating ovarian GHRH receptor and strengthening the development and maturation of follicles without triggering central and ovarian GH secretion.

Sleep-endocrine effects of growth hormone-releasing hormone (GHRH) in patients with schizophrenia.

Changes in sleep-EEG after endocrine stimulation tests in patients with schizophrenia include reduced sleep efficiency, prolonged sleep latency and increased awaking after sleep onset Findings on sleep associated growth hormone (GH) secretion were ambiguous. The aim of this study was to elucidate the sleep-endocrine activity especially in the GH system of patients with schizophrenia after repeated administration of GHRH. The effect of repetitive injections of 4 × 50 µg GHRH between 22.00 and 01.00 h on sleep endocrine parameters was investigated in 9 patients diagnosed for schizophrenia. Patients did not receive any medication for one week. Concentrations of ACTH, cortisol, prolactin and GH were determined. Patients spent three consecutive nights in the sleep laboratory. Blood was taken every 20min. Results were compared with matched healthy controls. A non-significant prolonged sleep onset latency and increased time awake was found in patients compared to controls. Sleep stage 2 was significantly reduced in patients. No significant difference in ACTH and cortisol was detected, whereas the GH secretion in patients following GHRH stimulation was significantly elevated compared to controls. Our results in drug free patients confirm already known changes in sleep-EEG in these patients. The GH response to GHRH-stimulation indicates a different regulatory sensitivity of the system between daytime and night-time.

Evaluation of growth hormone response to GHRH plus arginine test in children with idiopathic short stature: role of peak time.

PURPOSE: To describe the course of growth hormone response to growth hormone releasing hormone (GHRH) plus arginine provocative test in children with idiopathic short stature (ISS) and to evaluate the role of peak time. METHODS: A retrospective study was performed analyzing 344 GHRH plus arginine provocative tests performed in children and adolescents with short stature. Serum GH levels were measured at four-time points (T0', T30', T45' and T60') and GH peak was defined as the maximum value at any time point. Mean (T30'-T60') GH value and area under the curve (AUC) were calculated. RESULTS: When analyzing the time of peak at the provocative test, the most frequent peak time was T45' (53.8%) in the ISS group, with no differences in gender, age, and pubertal stage. Analyzing GHD subjects, the most frequent time of peak was T30 (50%). Analyzing the whole population, the GH T0' levels were significantly lower in subjects with the GH peak at T45' than those with the GH peak at T30' (1.7 ± 2.0 vs. 3.2 ± 4.0, p < 0.001). In subjects with GH peak at T45', the value of GH peak, AUC and mean GH were significantly higher than in those with GH peak at T30' and T60'. A direct correlation was found between the value of GH peak and growth velocity SDS (r = 0.127, p = 0.04) and a negative one between GH peak and GH level at T0' (r = - 0.111, p = 0.04), even when adjusted for gender, age, pubertal stage and BMI Z score. CONCLUSIONS: The time peak at 45 min seems to be associated with a better response to the test considering GH peak, mean and AUC. Patients with a GH peak at 30 min more probably could have a derangement in GH secretion showing worst growth pattern and/or a GH deficiency and should be carefully observed.

GHRH plus arginine and arginine administration evokes the same ratio of GH isoforms levels in young patients with Prader-Willi syndrome.

Human GH is present in pituitary and circulation as several isoforms, the prevalent being 22kDa- and 20kDa-GH. Recently, we have demonstrated the preservation of a normal balance in GH isoforms after GH releasing hormone (GHRH) plus arginine (ARG) administration in adult patients with Prader-Willi syndrome (PWS), one of the most common causes of syndromic obesity, often associated with GH deficiency (GHD). Aim of the present study was to measure circulating levels of 22kDa- and 20kDa-GH in young PWS patients (n=24; F/M: 10/14; genotype UPD/DEL/met+: 11/11/2; age: 10.8±5.3years; BMI SDS: 2.0±2.0; GHD: 16/24; obesity: 12/24) after combined GHRH+ARG or ARG administration. The results were analysed subdividing the GHRH+ARG and ARG groups on the basis of PWS genotype, GHD status and obesity. Circulating levels of 22kDa- and 20kDa-GH were measured by a chemiluminescent or fluorescent method based on specific pairs of monoclonal antibodies. GHRH+ARG or ARG significantly stimulated the secretion of 22kDa-GH but not that of 20kDa-GH in all PWS patients. No significant GHRH+ARG- vs. ARG-induced changes in the ratios of 22kDa- to 20kDa-GH peaks were observed in all PWS patients, although 22kDa- or 20kDa-GH peaks were significantly higher in the GHRH+ARG than ARG group. When subdividing PWS patients in UPD vs. DEL, obese vs. non obese and GHD vs. non GHD subgroups, GH peaks were significantly higher in nonobese than obese patients and in non GHD than GHD patients administered with either GHRH+ARG or ARG test, apart from the comparisons in the DEL/UPD subgroups. Anyway, the ratios of peak levels of 22kDa- to 20kDa-GH were similar after GHRH+ARG vs. ARG in all subgroups investigated. In conclusion, this study shows that administration of two different pharmacological tests, i.e. ARG, capable of reducing hypothalamic somatostatinergic tone, and GHRH (+ARG), that directly acts at pituitary level on the somatotropic cell, evokes the same ratios of GH isoforms in young PWS patients, suggesting that the hypothalamic dysfunction in this genetic disorder does not alter the qualitative and quantitative composition of GH isoforms present in circulation.

Gender has to be taken into account in diagnosing adult growth hormone deficiency by the GHRH plus arginine test.

OBJECTIVE: Data on the effect of gender on the interpretation of the GHRH plus arginine stimulation test (GHRH+ARG test) is controversial. We validated the GHRH+ARG stimulation test in control subjects and patients with organic or idiopathic pituitary disease and a suspicion of adult growth hormone deficiency (AGHD) using the Immulite 2000 XPi GH assay. DESIGN: We studied 126 apparently healthy adults (median age 38.8years) and 34 patients with a suspicion of AGHD (median age 42.2years). Identification of AGHD with the GHRH+ARG test was investigated with commonly accepted BMI-related consensus cut-off limits for peak GH concentrations. Serum samples collected during the GHRH+ARG test were analysed for GH in 2014-2015. Serum IGF-1 concentrations were studied as a reference. RESULTS: In 14 of 65 (22%) control males the GH peak value was below the BMI-related cut-off limits for GH sufficiency indicating a false diagnosis of AGHD. All control females had a normal GHRH+ARG response. Median peak GH response was significantly (p<0.001) higher in female (39.3µg/L) than in male controls (21µg/L). According to consensus cut-offs all but one young female patient had a deficient response compatible with a diagnosis of AGHD. CONCLUSIONS: The GH response to stimulation by GHRH+ARG is gender-dependent, being lower in healthy males than in females. Gender should be considered when defining cut-off limits for peak GH concentrations in the GHRH+ARG test. The presently used BMI-related cut-off levels will lead to a significant misclassification of males as GH deficient.

Safety and metabolic effects of tesamorelin, a growth hormone-releasing factor analogue, in patients with type 2 diabetes: A randomized, placebo-controlled trial.

OBJECTIVE: Use of growth hormone is associated with side effects, including insulin resistance. The objective of this study was to determine whether tesamorelin, a stabilized growth hormone-releasing hormone analogue, would alter insulin sensitivity or control of diabetes. DESIGN: A 12-week randomized, placebo-controlled study of 53 patients with type 2 diabetes. Three treatment groups: placebo, 1 and 2 mg tesamorelin. MEASUREMENTS: Fasting glucose, glucose and insulin from oral glucose tolerance test, glycosylated hemoglobin (HbA1c), home blood glucose, insulin-like growth factor-1, and lipids. MAIN OUTCOME MEASURE: Relative insulin response following oral ingestion of glucose. RESULTS: No significant differences were observed between groups in relative insulin response over the 12-week treatment period. At Week 12, fasting glucose, HbA1c and overall diabetes control were not significantly different between groups. In addition, relevant modifications in diabetes medications were similar between groups. Total cholesterol (-0.3±0.6 mmol/L) and non-HDL cholesterol (-0.3±0.5 mmol/L) significantly decreased from baseline to Week 12 in the tesamorelin 2 mg group (p<0.05 vs. placebo). No patient discontinued the study due to loss of diabetes control. CONCLUSIONS: Treatment of type 2 diabetic patients with tesamorelin for 12 weeks did not alter insulin response or glycemic control. TRIAL REGISTRATION: ClinicalTrials.gov NCT01264497.

Synthesis and structure-activity studies on novel analogs of human growth hormone releasing hormone (GHRH) with enhanced inhibitory activities on tumor growth.

The syntheses and biological evaluations of new GHRH analogs of Miami (MIA) series with greatly increased anticancer activity are described. In the design and synthesis of these analogs, the following previous substitutions were conserved: D-Arg2, Har9, Abu15, and Nle27. Most new analogs had Ala at position 8. Since replacements of both Lys12 and Lys21 with Orn increased resistance against enzymatic degradation, these modifications were kept. The substitutions of Arg at both positions 11 and 20 by His were also conserved. We kept D-Arg28, Har29 -NH2 at the C-terminus or inserted Agm or 12-amino dodecanoic acid amide at position 30. We incorporated pentafluoro-Phe (Fpa5), instead of Cpa, at position 6 and Tyr(Me) at position 10 and ω-amino acids at N-terminus of some analogs. These GHRH analogs were prepared by solid-phase methodology and purified by HPLC. The evaluation of the activity of the analogs on GH release was carried out in vitro on rat pituitaries and in vivo in male rats. Receptor binding affinities were measured in vitro by the competitive binding analysis. The inhibitory activity of the analogs on tumor proliferation in vitro was tested in several human cancer cell lines such as HEC-1A endometrial adenocarcinoma, HCT-15 colorectal adenocarcinoma, and LNCaP prostatic carcinoma. For in vivo tests, various cell lines including PC-3 prostate cancer, HEC-1A endometrial adenocarcinoma, HT diffuse mixed ß cell lymphoma, and ACHN renal cell carcinoma cell lines were xenografted into nude mice and treated subcutaneously with GHRH antagonists at doses of 1-5µg/day. Analogs MIA-602, MIA-604, MIA-610, and MIA-640 showed the highest binding affinities, 30, 58, 48, and 73 times higher respectively, than GHRH (1-29) NH2. Treatment of LNCaP and HCT-15 cells with 5µM MIA-602 or MIA-690 decreased proliferation by 40%-80%. In accord with previous tests in various human cancer lines, analog MIA-602 showed high inhibitory activity in vivo on growth of PC-3 prostate cancer, HT-mixed ß cell lymphoma, HEC-1A endometrial adenocarcinoma and ACHN renal cell carcinoma. Thus, GHRH analogs of the Miami series powerfully suppress tumor growth, but have only a weak endocrine GH inhibitory activity. The suppression of tumor growth could be induced in part by the downregulation of GHRH receptors levels.

Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions.

BACKGROUND: Communal online folk pharmacology fuels the drive for short cuts in attaining muscle enhancement, fat loss, and youthful skin. OBJECTIVES: The study used "netnography" to explore female use of CJC-1295, a synthetic growth hormone analogue from the perspectives contained in Internet forum activity. METHODS: A systematic Internet search was conducted using variation of the term "CJC-1295"; and combined with "forum." Ninety-six hits related to bodybuilding websites where CJC-1295 was mentioned. Following application of exclusion criteria to confine to female use and evidence of forum activity, 9 sites remained. These were searched internally for reference to CJC-1295. Twenty-three discussion threads relating to female use of CJC-1295 formed the end data set, and analyzed using the Empirical Phenomenological Psychological method. RESULTS: Forum users appeared well versed and experienced in the poly use of performance and image drug supplementation. Choice to use CJC-1295 centered on weight loss, muscle enhancement, youthful skin, improved sleep, and injury healing. Concerns were described relating to female consequences of use given gender variations in growth hormone pulses affecting estimation of dosage, cycling, and long-term consequences. CONCLUSIONS: Public health interventions should consider female self-medicating use of synthetic growth hormone within a repertoire of product supplementation, and related adverse health consequences.

Prediction of in-vivo iontophoretic drug release data from in-vitro experiments-insights from modeling.

A strategy was developed to predict in-vivo plasma drug levels from data collected during in-vitro transdermal iontophoretic delivery experiments. The method used the principle of mass conservation and the Nernst-Planck flux equation to describe molecular transport across the skin. Distribution and elimination of the drug in the body followed a one- or two-compartment open model. Analytical expressions for the relaxation constant and plasma drug concentration were developed using Laplace transforms. The steady-state dermal flux was appropriate for predicting drug absorption under in-vivo conditions only when the time constant in the skin was far greater than its value in the blood compartment. A simulation study was conducted to fully assess the performance of estimations based on the equilibrium flux approximation. The findings showed that the normalized integral of squared error decreased exponentially as the ratio of the two time constants (blood/skin) increased. In the case of a single compartment, the error was reduced from 0.15 to 0.016 when the ratio increased from 10 to 100. The methodology was tested using plasma concentrations of a growth-hormone releasing factor in guinea pigs and naloxone in rats.

Effects of hypothalamic dopamine on growth hormone-releasing hormone-induced growth hormone secretion and thyrotropin-releasing hormone-induced prolactin secretion in goats.

The aim of the present study was to clarify the effects of hypothalamic dopamine (DA) on the secretion of growth hormone (GH) in goats. The GH-releasing response to an intravenous (i.v.) injection of GH-releasing hormone (GHRH, 0.25 µg/kg body weight (BW)) was examined after treatments to augment central DA using carbidopa (carbi, 1 mg/kg BW) and L-dopa (1 mg/kg BW) in male and female goats under a 16-h photoperiod (16 h light, 8 h dark) condition. GHRH significantly and rapidly stimulated the release of GH after its i.v. administration to goats (P < 0.05). The carbi and L-dopa treatments completely suppressed GH-releasing responses to GHRH in both male and female goats (P < 0.05). The prolactin (PRL)-releasing response to an i.v. injection of thyrotropin-releasing hormone (TRH, 1 µg/kg BW) was additionally examined in male goats in this study to confirm modifications to central DA concentrations. The treatments with carbi and L-dopa significantly reduced TRH-induced PRL release in goats (P < 0.05). These results demonstrated that hypothalamic DA was involved in the regulatory mechanisms of GH, as well as PRL secretion in goats.

Central administration of chicken growth hormone-releasing hormone decreases food intake in chicks.

Growth hormone-releasing hormone (GHRH) is well known as a stimulator of growth hormone (GH) secretion. GHRH not only stimulates GH release but also modifies feeding behavior and energy homeostasis in rodents. In chickens (Gallus gallus domesticus), on the other hand, two types of GHRH, namely, chicken GHRH (cGHRH) and cGHRH-like peptide (cGHRH-LP), have been identified. The purpose of the present study was to investigate the effect of central injection of cGHRH and cGHRH-LP on feeding behavior in chicks. Intracerebroventricular (ICV) injection of both cGHRH and cGHRH-LP (0.04 to 1 nmol) significantly decreased food intake without any abnormal behavior in chicks. Furthermore, the feeding-inhibitory effect was not abolished by co-injection of the antagonist for pituitary adenylate cyclase-activating polypeptide (PACAP) or corticotropin-releasing hormone (CRH) receptors, suggesting that the anorexigenic effect of cGHRH and cGHRH-LP might not be related to the PACAP and CRH systems in the brain of chicks. Finally, 24-h food deprivation increased mRNA expression of cGHRH but not cGHRH-LP in the diencephalon. These results suggest that central cGHRH is related to inhibiting feeding behavior and energy homeostasis in chicks.