Human Growth Hormone Concentrations Research Articles

Can Human Growth Hormone Accelerate Tendon and Ligament Injury Recovery?

Studies involving human fibroblasts and use of human growth hormone (HGH) administration for injury recovery are limited. It is plausible that if the administration of HGH to human cells increased cellular proliferation and differentiation, then HGH might be able to assist in accelerating recovery from injury. HGH will increase proliferation and differentiation of human tendon and ligament fibroblasts in vitro based on both a single-dose and a sustained-dose model of HGH administration. Basic science cellular study. Human tendon and ligament tissue were harvested from 24 patients. Tissue samples were digested with type I collagenase to isolate the target cell types. HGH was administered directly to isolated cells at doses ranging from 100 pg/mL to 10 µg/mL, either in a single-dose or a sustained-dose model. Proliferation was analyzed at days 4 and 7. Differentiation of ligament and tendon fibroblasts was assessed at day 14. Administration of a single-dose of HGH to both cell types demonstrated similar or inferior cellular proliferation compared with controls after 7 days. For the sustained-dosing model of ligament fibroblasts, only the 100 ng/mL concentration demonstrated at least statistically similar or improved proliferation compared with controls. When examining the 100 ng/mL HGH concentration with larger sample sizes, cellular proliferation was not improved over controls for any cell type for the single- or sustained-dosing models. Proliferation for tendon fibroblasts was either similar or inferior to the control group at all concentrations of HGH. There was no clear dose-response relationship demonstrating enhanced collagen production with administration of HGH to suggest it enhances injury recovery. HGH administered to human tendon and ligament fibroblasts does not appear to positively affect cellular proliferation and differentiation. This study does not support the use of HGH for accelerating recovery from injury.

Human growth hormone level decreased in women aged 50 years.

To investigate the relationship amongst human growth hormone (HGH), sex, and age groups.A cross-sectional study was conducted on a health check-up population from Wannan area of China from 2014 to 2016. The study involved 6843 individuals aged 23 to 85 years. Logistic regression analysis and smooth curve were applied to determine the relationship amongst age, sex, and HGH.The average level of HGH in the population was 0.37 ± 0.59 ng/mL. There were significant differences in sex, age, body mass index (BMI), triglycerides (TG), total cholesterol (TC), systolic blood pressure (SBP), diastolic blood pressure (DBP), and glucose (GLU) amongst different quartiles of HGH (P < .001). A U-shape relationship was established between HGH and age. After sex stratification, the results showed that the thresholds of age were 60 years in women, and 50 years in men, after adjusting for body mass index, triglycerides, total cholesterol, blood pressure, and blood glucose. Logistic regression showed that HGH level decreased in women aged <60 years (OR = 1.472, P < .001) and increased in men aged >50 years (OR = 0.711, P < .001). So the distributive characteristics of HGH concentration vary with sex and age group.

Detection of early breast cancer beyond mammographic screening: a promising biomarker panel.

Aim: We assessed the suitability of a biomarker panel to improve early detection and individual risk assessment in breast cancer (BC) patients. Materials & methods: PENK, pro-SP, hGH and CA15-3 of 204 BC patients and 68 healthy controls were measured. Results: PENK and human growth hormone concentrations were significantly lower and pro-SP values higher in BC patients compared with controls. C-index increased from 0.628 for CA15-3 alone to 0.754 when all three biomarkers were added to the model. Conclusion: This biomarker panel may improve early detection of BC and influence the assessment of breast imaging. It might be useful for a risk-adapted cancer surveillance or primary prevention program by a more precise determination of an individualized BC risk.

Do anabolic nutritional supplements stimulate human growth hormone secretion in elderly women with heart failure?

Growth hormone treatment has gained attention over the past decade as a treatment for heart failure. Human growth hormone (HGH) must be administered by injections (usually daily), so there is considerable advantage to stimulation of endogenous secretion by amino acid‐based nutritional supplementation. However, studies investigating the effect of amino acid (AA) supplementation show conflicting results. Therefore, in this study we aimed to investigate the effect of nutritional supplementation on HGH production in elderly women with heart failure. Eight elderly women with heart failure participated in this randomized cross‐over study. Plasma HGH concentration was measured before and for 4 h following ingestion of a mixture of protein, carbohydrate, and fat or an AA beverage. HGH concentration was determined with ELISA kits and AA concentrations were analyzed by Liquid Chromatography–Mass Spectrometry (LCMS). Linear mixed models was performed to analyze the effect of time, treatment, and interaction. Plasma arginine and lysine concentrations were significantly higher after consumption of the AA drink compared to the mixture of protein, carbohydrate, and fat. Nonetheless, only ingestion of the protein, carbohydrate, and fat mixture (meal replacement) increased HGH concentration. HGH concentration was increased in elderly women with heart failure following consumption of a meal replacement containing protein, carbohydrate, and fat. Consumption of a mixture of amino acids failed to increase HGH concentration despite significantly greater elevations in plasma amino acid concentrations, including arginine and lysine. The stimulatory effect of the protein/carbohydrate/fat mixture was presumably mediated by factors other than increases in free amino acid concentrations.

Growth Hormone Response to Catecholamine Depletion in Unmedicated, Remitted Subjects With Major Depressive Disorder and Healthy Controls

We investigated whether the human growth hormone (HGH) response to catecholamine depletion differs between fully remitted patients with major depressive disorder and healthy control subjects. Fourteen unmedicated subjects with remitted major depressive disorder (RMDD) and 11 healthy control subjects underwent catecholamine depletion with oral α-methylparatyrosine (AMPT) in a randomized, placebo-controlled, double-blind crossover study. The main outcome measure was the serum level of HGH. The diagnosis × drug interaction for HGH serum concentration was significant (F₁,₂₃ = 7.66, P < 0.02). This interaction was attributable to the HGH level increasing after AMPT administration in the RMDD subjects but not in the healthy subjects. In the RMDD sample, the AMPT-induced increase in HGH concentration correlated inversely with AMPT-induced anxiety symptoms as assessed using the Beck Anxiety Inventory (r = -0.63, P < 0.02). There was a trend toward an inverse correlation of the AMPT-induced HGH concentration changes with AMPT-induced depressive symptoms as measured by the BDI (r = -0.53, P = 0.05). Following catecholamine depletion, the RMDD subjects were differentiated from control subjects by their HGH responses. This finding, together with the negative correlation between HGH response and AMPT-induced anxiety symptoms in RMDD subjects, suggests that AMPT administration results in a deeper nadir in central catecholaminergic transmission, as reflected by a greater disinhibition of HGH secretion, in RMDD subjects versus control subjects.

The efficacy of octreotide LAR in acromegalic patients as primary or secondary therapy

The objective of this study was to investigate the efficacy of octreotide therapy in acromegalic patients as primary or secondary therapy. Ten acromegalic patients diagnosed at the Endocrinology Clinic in Sarajevo (seven females and three males, mean age 55.2 ± 7.2 years, age range 40-65 years, five patients with microadenoma and five patients with macroadenoma) were treated with octreotide. Among them, 60% of patients were operated on and the majority of the procedures were performed transnasaly (90%). That group of patients had recidivism of disease (pituitary adenoma and acromegaly). The concentration of human growth hormone (HGH) and insulin-like growth factor 1 (IGF-1) was evaluated at 0, 6 and 12 months, while magnetic resonance imaging (MRI) was taken before the treatment and 12 months after. Eight patients received octreotide 30 mg/28 days, one patient received a dose of 20 mg and the other received 60 mg/28 days. Before treatment growth hormone (GH) levels were 50.87 ± 10.56 ng/ml (range: 26-64.9), IGF-1 were 776.66 ± 118.40 ng/ml (range: 526-934). Four patients (40%) were treated with primary octreotide treatment and six patients (60%) with secondary somatostatin analog treatment. At the beginning of therapy, there were no differences in terms of age, HGH levels and IGF-1 levels between primary and secondary treatment groups (p > 0.05). The difference between groups was only in regard to the size of tumors (p = 0.01). After 6 and 12 months the GH levels decreased to 1.61 ± 0.86 ng/ml (range: 0.7-2.65) and 1.85 ± 2.40 ng/ml (range: 0.0-8.3), respectively, while the IGF-1 became 305.90 ± 43.19 ng/ml after 6 months of treatment (range: 240-376) and 256.99 ± 71.43 ng/ml after 12 months of octreotide treatment (range: 126-325), respectively. The pituitary adenomas size prior to treatment was 9.57 mm, while after 12 months of treatment, the size decreased to 8.0 mm. After therapy, a GH decrease to less than 2.5 ng/ml was achieved in 90% of cases; tumor size decrease was achieved in 60% while normalization of IGF-1 was achieved in 100% of the patients, respectively. All differences about HGH and IGF-1 in each group were statistically significant (p < 0.05). In the group of acromegalic patients treated with octreotide LAR as primary therapy, the difference was more significant for GH and IGF-1 than for adenomas size. Octreotide treatment of acromegaly not only decreases GH and IGF-1 concentrations, but also appears to diminish the size of the tumor in about 60% of cases. The somatostatin analogs are more efficient in the primary treatment of acromegalic patients, due to the fact that primary therapy is as effective as secondary therapy but primary therapy has small advantages when compared with secondary octreotide therapy because no surgical treatment is required before.

Growth hormone/JAK‐STAT axis signal‐transduction defect

Primary cultured fibroblasts of four patients with idiopathic short stature and severe growth delay, which displayed normal growth hormone receptor expression presented a reduced ability for activation of signal transducer and activator of transcription-3 (STAT3). Impaired STAT3 activation was accompanied by cell-cycle arrest at the Go /G1 phase. Increased levels of the cyclin-dependent kinase inhibitor, p21(WAF/CIPI), and reduced levels of cyclins were also detected in these patients. High concentrations of human growth hormone (1000 ng x mL(-1)) added to the culture medium induced activation of STAT3 and reduced the levels of p21(WAF/CIPI) in the fibroblasts of the four idiopathic short stature children. Treatment of these children with exogenous human growth hormone significantly augmented their growth velocity. Overall, our study provides the first evidence linking the idiopathic short stature phenotype with a functional aberration in the growth hormone signal transduction cascade which can be successfully overcome by exposure to high doses of growth hormone.

Modelling, Synthesis and Realization of Hgh Mechanism Using Vhdl and Fpgas

The goal of this article is to develop a technique for realization of biological mechanisms onto a compact electronic chip. The chip allows researchers to carry out extensive investigations of the mechanisms. This investigation may yield to development of drugs to treat disorders that may exist in the mechanism. The authors present a hardware realization of a simplified Human Growth Hormone (HGH) secretion mechanism. The mechanism is developed into a flowchart and then simulated using Hardware Descriptive Language (HDL). After verifying the simulation results, computer-aided design (CAD) tools are used to synthesize the mechanism onto Xilinx FPGAs chip. The chip is tested by inputting signals with values corresponding to the concentration of GHRH and the concentration of SRIF. User-selected output pins on the chip show the concentration of HGH and the concentration of IGF-I. The outputs are compared with those generated by the simulation. Both the simulation and the chip generate identical patterns. The authors conclude that the chip mimics the HGH mechanism. The chip after synthesis is a stand-alone system that does not need a computer for operation. The chip operates on a real-time basis.

Modelling, Synthesis and Realization of HGH Mechanism Using VHDL and FPGAS

The goal of this article is to develop a technique for realization of biological mechanisms onto a compact electronic chip. The chip allows researchers to carry out extensive investigations of the mechanisms. This investigation may yield to development of drugs to treat disorders that may exist in the mechanism. The authors present a hardware realization of a simplified Human Growth Hormone (HGH) secretion mechanism. The mechanism is developed into a flowchart and then simulated using Hardware Descriptive Language (HDL). After verifying the simulation results, computer-aided design (CAD) tools are used to synthesize the mechanism onto Xilinx FPGAs chip. The chip is tested by inputting signals with values corresponding to the concentration of GHRH and the concentration of SRIF. User-selected output pins on the chip show the concentration of HGH and the concentration of IGF-I. The outputs are compared with those generated by the simulation. Both the simulation and the chip generate identical patterns. The authors conclude that the chip mimics the HGH mechanism. The chip after synthesis is a stand-alone system that does not need a computer for operation. The chip operates on a real-time basis.

A simple and sensitive assay for GH activity based on 3T3-F442A cell differentiation

We describe a fast, sensitive, specific, and simple in vitro assay for GH biological activity, based on the differentiation of 3T3-F442A cells into adipocytes. The 3T3-F442A cells were directly plated at 1.5 × 10 4 cells/cm 2 in medium with or without various concentrations of human growth hormone (hGH). After 7 days, cells were lysed with buffer containing 0.5 % (v/v) Triton X-100, and adipose conversion was quantitated by the activity of the adipogenic enzyme glycerophosphate dehydrogenase. The assay is highly sensitive and specific for GH from different species. These culture conditions have shortened the time for the cells to undergo adipose differentiation, and they might also be useful to design and test drugs or agents that modify adipocyte differentiation or lipid metabolism, or for evaluation of cytotoxic and pharmacologic effects of drugs and other compounds.

Effects of 3-day bed rest on physiological responses to graded exercise in athletes and sedentary men.

To test the hypotheses that short-term bed-rest (BR) deconditioning influences metabolic, cardiorespiratory, and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men and 10 endurance- and 10 strength-trained athletes were submitted to 3-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and heart rate (HR) were recorded continuously, and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate concentration ([LA]), epinephrine concentration ([Epi]), norepinephrine concentration ([NE]), plasma renin activity (PRA), human growth hormone concentration ([hGH]), testosterone, and cortisol determination. Reduction of peak oxygen uptake (VO(2 peak)) after BR was greater in the endurance athletes than in the remaining groups (17 vs. 10%). Decrements in VO(2 peak) correlated positively with the initial values (r = 0.73, P < 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased in the endurance athletes from 71 to 60% VO(2 peak) (P < 0.001); they also had an earlier increase in [NE], an attenuated increase in [hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion, reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

Insulin-like growth factor-I and alpha 2-macroglobulin in seminal plasma correlate with semen quality.

Insulin-like growth factor-I (IGF-I) and alpha 2-macroglobulin (alpha 2-M) are believed to be involved in the development of germ cells. IGF-I is mainly controlled by concentrations of human growth hormone (HGH), influences cell proliferation and differentiation and its action is mediated by insulin-like growth factor-binding proteins (IGFBP), placental protein 14 (PP14) and prostate-specific antigen (PSA). alpha 2-M acts as a broad spectrum proteinase inhibitor and a binding protein for many cytokines and hormones, e.g. inhibin and activin. This study was designed to identify concentrations of these molecules in seminal plasma in normal semen samples of healthy men, correlations with semen quality, the relationship of IGF-I and alpha 2-M with factors affecting male fertility, and whether vasectomy influences the concentrations of these molecules. Concentrations of IGF-I and alpha 2-M in human seminal plasma were related to semen quality, basal concentrations of HGH, testosterone, IGFBP-3, soluble fibronectin receptor (sFNR), PSA and PP14 in seminal plasma and to serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH). Commercially available assays were used to analyse 69 semen samples of various quality and 11 post-vasectomy samples. IGF-I concentrations in seminal plasma were significantly correlated with the percentage of morphologically normal spermatozoa (r = 0.748, P = 0.00001) and sperm concentration (r = 0.301, P = 0.011), but negatively correlated with serum FSH (r = -0.506, P = 0.00006) and PSA in seminal plasma (r = -0.388, P = 0.00009). Total alpha 2-M was significantly correlated with sperm count (r = 0.423, P = 0.0005), percentage of progressively motile spermatozoa (r = 0.444, P = 0.00019), quality of motility (sperm motile efficiency, r = 802, P = 0.00001) and straight line velocity (r = 0.411, P = 0.0013). Correlation between the sperm concentration and HGH in seminal plasma was weak (r = 0.287, P = 0.015). Vasectomy reduced the concentration of total alpha 2-M (P = 0.00008) and HGH (P = 0.0068) in the seminal plasma; IGF-I was also reduced after vasectomy when the total ejaculate amount was considered. Thus IGF-I and alpha 2-M are significant for the germ cell development: IGF-I in the maturation of spermatozoa and alpha 2-M in progressive motility.

Physiological and performance responses to nicotinic-acid ingestion during exercise

The purpose of this study was to assess how selected physiological and performance responses are affected when the normal increase in plasma free fatty acid concentration during exercise is blunted by ingesting nicotinic acid. On four occasions, 10 subjects cycled at 68 +/- 1% VO2peak for 120 min followed by a timed 3.5-mile performance task. Every 15 min during exercise, subjects ingested 3.5 ml.kg LBM-1 of one of four beverages: 1) water placebo (WP), 2) WP + 280 mg nicotinic acid.l-1 (WP + NA), 3) 6% carbohydrate-electrolyte beverage (CE), and 4) CE + NA. Ingestion of nicotinic acid (WP + NA and CE + NA) blunted the rise in FFA associated with WP and CE; in fact, NA ingestion effectively prevented FFA from rising above rest values. The low FFA levels with NA feeding were associated with a 3- to 6-fold increase in concentrations of human growth hormone throughout exercise. The mean performance time for CE (10.7 min) was significantly less than for WP (12.2 min) and WP + NA (12.8 min), but did not differ from CE + NA (11.4 min). The results indicate that blunting the normal rise in FFA alters the hormonal response to exercise and reduces the capacity to perform high-intensity exercise.

Bioequivalence of Two Recombinant Human Growth Hormones in Healthy Male Volunteers after Subcutaneous Administration.

The bioequivalence of recombinant human growth hormone (rhGH) (somatropin) and its N-methionyl variant (Met-hGH) [Protropin((R)) (somatrem for injection)] was determined in 42 healthy male volunteers (n = 21 per treatment) who were randomized to receive either protein by subcutaneous administration of 0.1 mg kg(minus sign1). Serum samples were collected over 24 h after the injection, and the concentration of human growth hormone (hGH) were determined by an immunoradiometric assay. Bioequivalence of the two proteins was assessed by determining whether the 90% confidence limits for the ratio of geometric means using logarithmically transformed AUC and C(max) parameters (log(10)AUC(0--24), log(10)AUC(0--infty infinity), and log(10)C(max)) were within the 80--125% range. The bioequivalence of the two treatments was also tested by calculating a bioequivalance index (xi(2)) that measured the difference between the two mean concentration-time profiles. The 90% confidence intervals for the ratios of the geometric means for AUC were within the prescribed 80--125% range for bioequivalence. The upper limit of the 90% confidence interval for the ratio of the geometric means for C(max) fell slightly outside the 125% criterion even though the geometric mean itself, 106.6%, was very close to the ideal of 100%. There was a larger standard error associated with C(max) than with the AUCs, and this marginally larger confidence limit for C(max) resulted more from the variance among the subject than to the difference in the means. In fact, the bioequivalence index, xi(2), was 0.075, indicating that the mean curves after rhGH and Met-hGH are essentially superimposable.

Effects of exercise during normoxia and hypoxia on the growth hormone-insulin-like growth factor I axis.

The response of plasma insulin-like growth factor I (IGF I) to exercise-induced increase of total human growth hormone concentration [hGHtot] and of its molecular species [hGH20kD] was investigated up to 48 h after an 1-h ergometer exercise at 60% of maximal capacity during normoxia (N) and hypoxia (H) (inspiratory partial pressure of oxygen = 92 mmHg (12.7 kPa); n = 8). Lactate and glucose concentrations were differently affected during both conditions showing higher levels under H. Despite similar maximal concentrations, the increase of human growth hormone (hGH) was faster during exercise during H than during N[hGHtot after 30 min: 8.6 (SD 11.4) ng.ml-1 (N); 16.2 (SD 11.6) ng.ml-1 (H); P < 0.05]. The variations in plasma [hGH20kD] were closely correlated to those of [hGHtot], but its absolute concentration did not exceed 3% of the [hGHtot]. Plasma IGF I concentration was significantly decreased 24 h after both experimental conditions [N from 319 (SD 71) ng.ml-1 to 228 (SD 72) ng.ml-1, P < 0.05; H from 253 (SD 47) to 200 (SD 47) ng.ml-1, P < 0.01], and was still lower than basal levels 48 h after exercise during H [204 (SD 44) ng.ml-1, P < 0.01]. Linear regression analysis yielded no significant correlation between increase in plasma [hGHtot] or [hGH20kD] during exercise and the plasma IGF I concentration after exercise. It was concluded that the exercise-associated elevated plasma [hGH] did not increase the hepatic IGF I production. From our study it would seem that the high energy demand during and after the long-lasting intensive exercise may have overridden an existing hGH stimulus on plasma IGH I, which was most obvious during hypoxia.

Another look at co-treatment with growth hormone and human menopausal gonadotrophins in poor ovarian responders

The objective of this study was to evaluate whether a combined human growth hormone (HGH) and human menopausal gonadotrophin (HMG) treatment can improve ovulation induction in poor ovarian responders. Ten patients aged 28-43 years and requiring > 25 ampoules of HMG for ovulation were admitted to the study. Pituitary growth hormone reserve was evaluated by clonidine stimulation and insulin tolerance tests before commencement of treatment. The patients underwent one treatment cycle with D-tryptophan-6-luteinizing hormone-releasing hormone (D-Trp6-LHRH) and HMG and another cycle with D-Trp6-LHRH, HMG and HGH. Serum HGH, insulin-like growth factor (IGF)-I and oestradiol were measured throughout the two treatment cycles and follicular maturation was assessed by ultrasonographic studies. All patients tested showed no elevation of their serum HGH concentration during a clonidine test, but showed an adequate response during insulin tolerance tests. No significant difference was found in the number of HMG ampoules, duration of treatment, number of leading follicles, and serum oestradiol concentration between the two treatment cycles. Co-treatment with HGH and HMG did not improve ovarian performance in poor ovarian responders. No correlation was found between the results of HGH pituitary function tests and the ovarian response to gonadotrophins.

Growth hormone regulates ammoniagenesis in canine renal proximal tubule segments.

To determine whether growth hormone (GH) directly affects ammoniagenesis in the renal proximal tubule, ammonia production was measured in suspensions of isolated canine renal proximal tubule segments (IPTs) incubated with 2.5 mM L-glutamine and varying concentrations of human growth hormone (hGH). Ammonia production from IPTs significantly increased by nearly threefold in the presence of hGH (10(-6) M) at 60 min. This increase was dose dependent, with as little as 10(-9) M hGH significantly stimulating ammonia production. In addition, hGH enhanced glucose production when lactate, alanine, and succinate replaced L-glutamine as substrate. hGH significantly stimulated ammonia production when IPTs were incubated at alkalotic and neutral pH. The effect of hGH was lost at acidic pH. When hGH was added to IPTs incubated under Na(+)-equilibrated conditions, ammonia production was not different from control. hGH stimulated ouabain-sensitive Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity by 8.1 +/- 1.1% in basolateral membranes isolated from IPTs. hGH stimulation of proximal tubule ammonia production from L-glutamine occurs at physiological concentrations of hGH and when the extracellular-to-intracellular Na+ gradient favors L-glutamine transport. This effect is associated with an increase in basolateral Na(+)-K(+)-ATPase activity. The data suggest a role for hGH in the regulation of renal acid-base metabolism under physiological conditions in which increased net acid excretion is important.

Urinary excretion of human growth hormone in children with short stature: Correlation with pituitary secretion of human growth hormone

Thirty-five children with short-stature underwent insulin-loading and sleep tests for assessment of secretion of human growth hormone. Correlations between the levels of human growth hormone in the serum and urine during the tests were examined to elucidate the clinical significance of urinary human growth hormone levels in short children. The concentration and total amount of human growth hormone in the urine correlated significantly with the peak concentration of serum human growth hormone (r = 0.81, p less than 0.001 and r = 0.80, p less than 0.001, respectively) and the integrated concentration of human growth hormone (r = 0.85, p less than 0.001 and r = 0.85, p less than 0.001, respectively) in the insulin-loading test. The concentration and total amount of human growth hormone in the morning urine also correlated significantly with the peak concentration of serum human growth hormone (r = 0.80, p less than 0.001 and r = 0.70, p less than 0.001, respectively) and the integrated concentration of serum human growth hormone (r = 0.80, p less than 0.001 and r = 0.72, p less than 0.001, respectively) in the sleep test. The concentration or total amount of human growth hormone in the urine differed significantly among children with human growth hormone deficiency, those with nonendocrine short stature, and those with normal stature (p less than 0.05). These data suggest that measurement of human growth hormone in the urine may be used to assess secretion of human growth hormone, serving as a screening test for human growth hormone deficiency in children.

Neuroendocrinological investigations during sleep deprivation in depression II. Longitudinal measurement of thyrotropin, TH, cortisol, prolactin, GH, and LH during sleep and sleep deprivation

Thyrotropin (TSH), thyroxin (T4), triiodothyronine (T3), free T3 (fT3), cortisol, prolactin, and human growth hormone (HGH) were measured every 2 hr during a night of sleep, the following day, and a night of sleep deprivation (SD) in 14 patients with major depressive disorder. In subgroups fT4 (n = 5), reverse T3 (rT3), and luteinizing hormone (LH) (n = 6) were also investigated. Significant increases in TSH, T4, fT4, T3, fT3, rT3, and cortisol and decreases in prolactin levels occurred during the night of SD, compared to the pattern during the night of sleep. The pre-SD T4 and T3 levels of the responders to SD were already higher than in the nonresponders, and increased less during SD. The cortisol and HGH concentrations of the responders rose higher during SD than those of the nonresponders. Changes in TSH and prolactin were not correlated to clinical response. Analysis of possible neurochemical mechanisms underlying this “pattern” of changes in different endocrine profiles suggests that enhanced noradrenergic activity might play a role in the changes in TSH, cortisol, thyroid hormones, and possibly HGH secretion during SD, and increased dopaminergic tone probably induced the decline in prolactin levels. Additional effects of the serotonergic system cannot be excluded at present. In conclusion, the data suggest that enhanced noradrenergic activity of the locus coeruleus stimulates alpha and/or beta adrenergic receptors in depressed patients during SD. This mechanism could well be involved in the antidepressant effect of this therapy.

Impact of human growth hormone on plasma lipoprotein concentrations.

To evaluate whether the moderately elevated human growth hormone concentration, seen in insulin dependent diabetic patients, has any impact on lipoproteins, human growth hormone was given to nondiabetic persons in doses which would bring their plasma human growth hormone concentration up in the same level as seen in insulin dependent diabetic patients. After one week of treatment with human growth hormone we found total plasma triglyceride to be significantly raised (0.98 mmol/l +/- 0.28 mmol/l (mean +/- SD) before versus 1.27 mmol/l +/- 0.38 mmol/l (mean +/- SD) after treatment). Very low density lipoprotein (VLDL) was separated into two fractions (VLDL-1 and VLDL-2) of which VLDL-2 is regarded as a VLDL-remnant which is suggested to be of importance for development of atherosclerosis. After one week of human growth hormone treatment there were no changes in VLDL-1 concentrations whereas a significant raise in VLDL-2 triglyceride and VLDL-2 cholesterol was seen.