Growth Hormone Release In Patients Research Articles

Acute cortisol administration increases sleep depth and growth hormone release in patients with major depression

Acute administration of cortisol increases non-rapid-eye movement (non-REM) sleep, suppresses rapid-eye movement (REM) sleep and stimulates growth hormone (GH) release in healthy subjects. This study investigates whether cortisol has similar endocrine and electrophysiological effects in patients with depression who typically show a pathological overactivity of the hypothalamus–pituitary–adrenal (HPA) system. Fifteen depressed inpatients underwent the combined dexamethasone/corticotropin-releasing hormone test followed by three consecutive sleep EEG recordings in which the patients received placebo (saline) and hourly injections of cortisol (1 mg/KG BW). Cortisol increased duration and intensity of non-REM sleep in particular in male patients and stimulated GH release. The activity of the HPA axis appeared to influence the cortisol-induced effects on non-REM sleep and GH levels. Stimulation of delta sleep was less pronounced in patients with dexamethasone nonsuppression. In contrast, REM sleep parameters were not affected by the treatment. These data demonstrate that the non-REM sleep-promoting effects of acute cortisol injections observed in healthy controls could be replicated in patients with depression. Our results suggest that non-REM and REM sleep abnormalities during the acute state of the disease are differentially linked to the activity of the HPA axis.

Endurance exercise modulates levodopa induced growth hormone release in patients with Parkinson's disease

Acute levodopa (LD) application and exercise release human growth hormone (GH). An earlier trial showed, that combined stimulus of exercise and LD administration is the best provocative test for GH response in healthy participants. Objective was to show this combined effect of LD application and exercise on GH response and to investigate the impact on LD metabolism in 20 previously treated patients with Parkinson's disease (PD). We measured GH- and LD plasma concentrations following soluble 200 mg LD/50 mg benserazide administration during endurance exercise and rest on two separate consecutive days. GH concentrations significantly increased on both days, but GH release was significantly delayed during rest. LD metabolism was not altered due to exercise in a clinical relevant manner. Exercise induced a significant faster LD stimulated GH release in comparison with the rest condition. We did not find the supposed increase of LD induced GH release by endurance exercise. We assume, that only a limited amount of GH is available for GH release in the anterior pituitary following an acute 200 mg LD administration. GH disposal also depends on growth hormone releasing hormone (GHRH), which is secreted into hypothalamic portal capillaries. During the exercise condition, the resulting higher blood pressure supports blood flow and thus GHRH transport towards the GH producing cells in the pituitary. This might additionally have caused the significant faster GH release during exercise.

Secretory Mechanisms of Growth Hormone (GH)-Releasing Peptide-, GH-Releasing Hormone-, and Thyrotropin-Releasing Hormone-Induced GH Release in Patients with Acromegaly

Secretory Mechanisms of Growth Hormone (GH)-Releasing Peptide-, GH-Releasing Hormone-, and Thyrotropin-Releasing Hormone-Induced GH Release in Patients with Acromegaly

Secretory mechanisms of growth hormone (GH)-releasing peptide-, GH-releasing hormone-, and thyrotropin-releasing hormone-induced GH release in patients with acromegaly.

The GH secretory mechanism of GH-releasing hexapeptide (GHRP-6), GHRH, and TRH were studied in vivo and in vitro in seven patients with acromegaly. In an in vivo study, these patients showed clear GH responses to single administration of GHRP (four of four patients), GHRH (seven of seven patients), and TRH (seven of seven patients) and enhanced responses to GHRP plus GHRH (two of four patients) or TRH plus GHRH (six of six patients). In an in vitro dispersed cell study, the majority of patients examined also showed clear GH responses to GHRP (four of four patients), GHRH (six of six patients), and TRH (four of four patients) and an enhanced response to GHRP plus GHRH (three of three patients) or TRH plus GHRH (three of four patients). In one patient (no. 3), GHRP plus forskolin (adenylate cyclase activator), but not GHRP plus phorbol 12-myristate 13-acetate (protein kinase C activator), additively enhanced the GH response. Nordihydroguaiaretic acid (NDGA; inhibitor of arachidonic cascade) inhibited GH release induced by GHRP, TRH, GHRH, TRH plus GHRH, or GHRP plus GHRH, but did not inhibit basal GH secretion. In contrast, NDGA distinctly elevated intracellular cAMP levels in another patient (no. 7) when coadministered with GHRP, GHRH, or GHRP plus GHRH, whereas cAMP levels were not modified by single administration of GHRP and NDGA. The GH response to the combined administration of GHRP and GHRH was synergistic in this patient, but was additive in the other two patients. It is concluded that GHRP, TRH, and GHRH directly stimulate in vivo and in vitro GH release from human somatotropinomas, and GHRP and TRH mainly exert their action through activation of the phosphatidylinositol-protein kinase C pathway, whereas GHRH exerts its action through the adenylate cyclase-protein kinase A pathway. These three agents seem to release GH via the arachidonic cascade.

Sumatriptan-induced growth hormone release in patients with major depression, mania, and normal controls

The purpose of this study was to assess serotonergic function in patients with major depression or mania using sumatriptan, a novel 5-HT1D receptor agonist, as a pharmacological probe in a neuroendocrine challenge paradigm. We studied 18 drug free patients (10 with acute unipolar major depression and 8 with acute mania) who met DSM-IV criteria, and healthy controls. Subjects presented for testing after an overnight fast. After obtaining a blood sample for baseline growth hormone (GH) levels, sumatriptan (6 mg) was given subcutaneously, and further blood samples were collected at half hour intervals for 2 hours. The results showed that GH responses to sumatriptan were blunted in depressed patients but not in manics, compared to healthy controls. There were no differences in basal GH levels between the 3 groups. The results of this study provide further support for the role of serotonergic system in pathophysiology of major depression, but not in mania.

The effects of thyrotropin-releasing hormone and luteinizing hormone-releasing hormone on growth hormone release in patients with homozygous beta-thalassaemia.

Serum GH levels were measured in 12 multitrans- patients, whereas no effect was observed in the normal subjects, fused patients with β-thalassaemia and in 12 normal subjects ofcomparable age under control conditions and after the administration of synthetic TRH and synthetic LRH. TRH administration induced a paradoxical rise in GH levels in 8 out of 12 patients, whereas no effect was observed in the normal subjects. Synthetic LRH administration was devoid of any effect on serum GH in both patients and controls. (J Clin Endocrinol Metab 54:1271, 1982)

Pituitary function in Hand-Schüller-Christian disease. Evidence for deficient growth-hormone release in patients with short stature.

Abstract Anterior and posterior pituitary function was evaluated in 13 patients with Hand–Schuller–Christian disease, including eight with growth retardation. Growth-hormone reserve, determined by insulin-induced hypoglycemia, arginine tolerance test or pyrogen stimulation, was deficient in seven of the eight short patients and in three of the patients whose disease developed after adult height had been attained. Tests of gonadotropin secretion and adrenocortical and thyroid function gave normal results. A dehydration test demonstrated complete diabetes insipidus in eight patients and incomplete diabetes insipidus in two. Growth-hormone deficiency was usually found when diabetes insipidus was present. Both abnormalities may be accounted for by a single hypothalamic lesion. The short stature frequently observed in patients with this disease may be in part secondary to quantitative growth-hormone deficiency.