Growth Hormone Secretion in Acid-Base Alterations at Rest and during Exercise

1976 ◽  
Vol 50 (4) ◽  
pp. 241-247 ◽  
Author(s):  
J. R. Sutton ◽  
N. L. Jones ◽  
C. J. Toews
Keyword(s):  
Growth Hormone ◽  
Lactic Acid ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Cycle Ergometer ◽  
Ion Concentration ◽  
Plasma Growth Hormone ◽  
Double Blind ◽  
Hydrogen Ion Concentration ◽  
Ergometer Exercise

1. Seven healthy males were studied during cycle ergometer exercise at 33%, 66% and 90% of V̇o2 max. on three occasions when NH4Cl, NaHCO3 or CaCO3 (as a control substance) were administered in gelatin capsules double blind and in randomized order. Plasma growth hormone (HGH), lactic acid and hydrogen ion concentration ([H+])weremeasured at frequent intervals. 2. Ammonium chloride produced highest blood [H+] and NaHCO3 the lowest. These differences were maintained during exercise and in recovery. Plasma lactic acid concentrations were similar at rest. At 66%, 90% V̇o2 max. and recovery lactic acid was highest with NaHCO3 and lowest with NH4Cl. 3. Exercise stimulated HGH secretion in all studies and the elevation was proportional to the intensity of the exercise. NH4Cl caused a variable elevation of HGH at rest and 33% V̇o2 max. At 66% V̇o2 max., plasma HGH was significantly elevated to similar concentrations in all studies and, at 90% V̇o2 max., HGH was highest with NaHCO3. 4. An infusion of sodium l(+)-lactate producing plasma lactate concentrations of 3–5 mmol/l did not influence HGH secretion. 5. Exercise is a physiological stimulus to HGH secretion and the mechanism is independent of blood [H+] and lactate concentrations.

scholarly journals Acute Arginine Supplementation Is Associated with Increased Growth Hormone in Younger Healthy Males: A Randomized Controlled Trial

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 609-609
Author(s):  
John Apolzan ◽  
Jennifer Rood ◽  
Robbie Beyl ◽  
Shengping Yang ◽  
Frank Greenway ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Repeated Measures ◽  
Controlled Trial ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Sex Hormone Binding Globulin ◽  
Double Blind ◽  
Time Points ◽  
Arginine Supplementation ◽  
Time Point

Abstract Objectives Assess the effects of the amino acid arginine on growth hormone (GH), other metabolites, and mood. Arginine is reported to increase GH, but the mechanism is not known. It was hypothesized prolactin mediated this effect since it is similar in structure to GH and, like GH, is secreted by the pituitary gland. Methods Thirty physically active healthy young males (18–39 y; 18.5–25 kg/m2) were enrolled in a randomized, double-blind, placebo-controlled, crossover trial. Two days prior and 1 day following each treatment a standardized diet was provided that maintained arginine at 3–5 g/d. Arginine or placebo treatments in the form of a beverage were consumed after an overnight fast. Treatment conditions were separated by at least a one week washout period. The beverages contained either 10 g of arginine or 0 g (placebo). Blood was collected at baseline and 1.5, 3.0, and 24 hr post treatment. Plasma GH, prolactin, amino acids, glucose, insulin, triacylglycerols, thyroid hormones, sex hormone binding globulin (SHBG), testosterone, cortisol, and dehydroepiandrosterone (DHEA) were assessed. The Profile of Mood States (POMS) was administered at the same time as blood draws. Repeated measures ANOVAs were used to estimate treatment effects at each time point. Results Arginine increased plasma arginine at 1.5, 3.0, and 24 hr (P ≤ 0.001) and GH at 24 hr (P ˂ 0.05) but not other time points. Arginine increased glucose and insulin at the 1.5 and 3.0 hr (P ˂ 0.05) but not 24 hr. Arginine did not affect any other dependent measure (P > 0.05) including prolactin. When only individuals with detectable levels of GH (responders; n = 16) were analyzed separately, arginine increased GH at the 1.5 (P ˂ 0.05) but not the 3.0 or 24 hr time points. Among the responders, arginine also increased thyroid stimulating hormone (TSH) at the 24 hr time point (P ˂ 0.05) but not the 1.5 and 3.0 hr time points. Conclusions Arginine supplementation modestly increased growth hormone. Despite their similar structures, prolactin secretion was not elevated following arginine supplementation, thus another mechanism is responsible for growth hormone secretion. Funding Sources DoD and NIH P30DK072476. Views expressed are those of the authors and do not reflect official policy of the Army, DoD, or US Government.

DIFFERENT EFFECTS OF EXOGENOUS CYCLIC ADENOSINE MONOPHOSPHATE AND ITS DIBUTYRYL DERIVATIVE ON PLASMA GROWTH HORMONE, GLUCOSE, INSULIN AND CORTISOL

1976 ◽  
Vol 83 (1) ◽  
pp. 15-25
Author(s):  
M. Vanderschueren-Lodeweyckx ◽  
W. Proesmans ◽  
E. Eggermont ◽  
R. Eeckels
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Normal Subjects ◽  
Immunoreactive Insulin ◽  
Plasma Growth Hormone ◽  
Hormone Levels ◽  
The Mean

ABSTRACT The effects of the infusion in four different dosages (0.001, 0.005, 0.02 and 0.2 mg/kg/min during 60 min) of cyclic 3′,5′-adenosine monophosphate and of its dibutyryl derivative on plasma growth hormone and on glucose, immunoreactive insulin and cortisol were studied in 38 normal subjects and in 10 patients with idiopathic hypopituitarism. In normal subjects cyclic 3′,5′-adenosine monophosphate provokes an increase in plasma growth hormone levels (only when a dosage of 0.2 mg/kg/min is used) without any changes in plasma glucose, insulin and cortisol. The maximal value of the means is observed 75 min after starting the infusion. Dibutyryl cyclic 3′,5′-adenosine monophosphate (0.2 and 0.02 mg/kg/min) provokes a dose-related rise in plasma growth hormone levels which is always preceded by hyperglycaemia and hyperinsulinaemia. The peak of the mean growth hormone levels occurs at 135 min after initiation of the infusion. In all but one hypopituitary patients the nucleotides do not promote growth hormone secretion. It is concluded that exogenous cyclic 3′,5′-adenosine monophosphate and its dibutyryl derivative may not be considered as analogous and that both compounds may contribute to study growth hormone release in normal subjects and in patients with growth abnormalities.

Increased hypothalamic somatostatin mRNA following dexamethasone administration in rats

1992 ◽  
Vol 127 (5) ◽  
pp. 416-419 ◽  
Author(s):  
Koji Nakagawa ◽  
Tatsuya Ishizuka ◽  
Chikara Shimizu ◽  
Yoshito Ito ◽  
Ichiji Wakabayashi
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Female Rats ◽  
Mrna Levels ◽  
Plasma Growth Hormone ◽  
Hormone Production ◽  
Blot Technique ◽  
Series Of Experiments

There is increasing evidence to suggest that supraphysiological doses of glucocorticoids suppress growth hormone secretion in vivo by augmenting somatostatin release from the hypothalamus; previously, we reported an increase in hypothalamic somatostatin content in dexamethasone-treated rats. To further examine whether the production of somatostatin really is augmented, hypothalamic somatostatin mRNA levels were determined by the Northern blot technique in female rats receiving 330 μg of dexamethasone daily for three days. In two series of experiments, hypothalamic somatostatin mRNA levels in dexamethasone-treated rats were significantly (p<0.05) increased to 133±19 (mean±sd)% and 153±38% of the controls. In the dexamethasone-treated rats, plasma growth hormone levels were markedly suppressed compared with those of the controls. These results further support the hypothesis that pharmacological doses of glucocorticoids increase the production and release of somatostatin from the hypothalamus and thus inhibit growth hormone secretion, overriding the direct stimulatory effect of glucocorticoids on growth hormone production at the pituitary level.

Effect of synthetic thyrotrophin-releasing hormone and its analogues on growth hormone secretion in the domestic fowl (Gallus Domesticus)

1981 ◽  
Vol 97 (4) ◽  
pp. 448-453 ◽  
Author(s):  
C. G. Scanes ◽  
S. Harvey ◽  
B. A. Morgan ◽  
M. Hayes
Keyword(s):  
Growth Hormone ◽  
Domestic Fowl ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Gallus Domesticus ◽  
Plasma Growth Hormone ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Trh Analogues

Abstract. Variations in plasma growth hormone (GH) concentrations following iv or sc administration of synthetic thyrotrophin-releasing hormone (TRH, Pyr-His-Pro-NH2) have been followed in immature and adult domestic fowl. TRH markedly stimulated GH secretion in newly hatched (1 and 2 day old) chicks and in 6-week-old cockerels but in adult male or female birds of two strains had very little effect, if any. Intravenous injection of 4 TRH analogues (Pyr-His-Mep-NH2, Pyr-Meh-Mep-NH2, Pyr-Meh-Mep-NH and Pyr-Meh-Pro-NH2) were also potent GH secretagogues in 6-week-old birds. The stimulatory effect of TRH or the TRH-analogues on GH secretion was not dose-related.

CHANGES IN PLASMA GROWTH HORMONE AND INSULIN OF THE HUMAN FOETUS FOLLOWING HYSTEROTOMY

1971 ◽  
Vol 66 (4) ◽  
pp. 577-586 ◽  
Author(s):  
R. C. Turner ◽  
B. Schneeloch ◽  
P. Paterson
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Immunoreactive Insulin ◽  
Plasma Growth Hormone ◽  
Plasma Insulin Concentration ◽  
Plasma Immunoreactive Insulin ◽  
The Mean ◽  
Serial Samples

ABSTRACT Plasma immunoreactive insulin and growth hormone of 20–24 weeks' gestation human foetuses were assayed in serial samples following delivery by hysterotomy. The mean umbilical cord plasma growth hormone concentration was 71 ng/ml (range 13–120 ng/ml) and the mean plasma insulin was 5 μU/ml (range 2–8 μU/ml). Following delivery the growth hormone levels increased, but there was no significant change in plasma insulin concentration. The hypothalamic-hypophyseal axis controlling growth hormone secretion appears to be developed by 20 weeks' gestation, and »stress« appears to be a provocative stimulus.

scholarly journals The dopaminergic regulation of plasma growth hormone secretion in normal subjects.

1986 ◽  
Vol 148 (2) ◽  
pp. 151-158 ◽  
Author(s):  
KUNIHIKO HANEW ◽  
SHUICHI SATO ◽  
ATSUSHI SASAKI ◽  
MEIGAN GOH ◽  
YASUYUKI SHIMIZU ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Normal Subjects ◽  
Plasma Growth Hormone ◽  
Dopaminergic Regulation

PITUITARY CONTENT AND PLASMA LEVELS OF GROWTH HORMONE IN FOETAL AND WEANLING RATS

1974 ◽  
Vol 60 (2) ◽  
pp. 261-268 ◽  
Author(s):  
M. RIEUTORT
Keyword(s):  
Growth Hormone ◽  
Plasma Levels ◽  
Hormone Level ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Growth Hormone Level ◽  
Plasma Growth Hormone ◽  
Pituitary Growth Hormone ◽  
Weanling Rats ◽  
Newborn Animals

SUMMARY Pituitary and plasma growth hormone were measured in foetal and weanling rats. Growth hormone was first detected in the pituitary (66 ± 8 ng) and plasma (26 ± 2 ng/ml) of 19·5-day-old foetuses. Pituitary growth hormone content increased rapidly up to the end of gestation and after birth. Plasma levels were high after 21·5 days of gestation (147 ± 8 ng/ml) and a further increase was observed at birth. The plasma growth hormone level fell to that of adult levels 5–10 days after birth. An early modulation of growth hormone secretion is discussed since newborn rats aged 2 h showed a rapid decrease in plasma levels at 25 °C while there was no such decrease in newborn animals maintained at 37 °C.

Evaluation of growth hormone response to insulin-induced hypoglycaemia in dairy cattle during a 670-day lactation

2014 ◽  
Vol 54 (9) ◽  
pp. 1323 ◽  
Author(s):  
L. C. Marett ◽  
M. J. Auldist ◽  
W. J. Wales ◽  
K. L. Macmillan ◽  
K. DiGiacomo ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Tolerance Test ◽  
Insulin Tolerance Test ◽  
Growth Hormone Response ◽  
Delayed Response ◽  
Hormone Response ◽  
Plasma Growth Hormone ◽  
Insulin Tolerance

Plasma growth hormone secretion in response to insulin-induced hypoglycaemia was evaluated in cows undergoing an extended lactation. Twelve multiparous Holstein-Friesian cows that calved in late winter and were managed for a 670-day lactation by delaying mating. Four experimental periods of 40 days commenced at ~73, 217, 422 and 520 (±9.1; mean ± s.d.) days in milk (DIM) during which cows were individually offered a diet of perennial ryegrass (73 and 422 DIM) or pasture hay and pasture silage (217 and 520 DIM) supplemented with either 1 kg DM grain (CONT) or 6 kg DM grain (GRAIN). Cows were fitted with jugular catheters during the final week of each experimental period. Seven blood samples over a 24-h period were collected and an insulin tolerance test was performed on each cow using a dose of 0.12 µU insulin/kg liveweight at ~100, 250, 460 and 560 DIM. This resulted in an increase in plasma growth hormone concentration occurring at 100 DIM, an intermediate and delayed response at 250 DIM, and no response at both 460 and 560 DIM. Cows in the CONT treatment had higher basal plasma growth hormone concentrations and tended to have a greater peak growth hormone response than GRAIN cows. The growth hormone response at 100 and 250 DIM is likely a homeorhetic mechanism to support milk yield during early-mid lactation. These observations are consistent with the known actions of growth hormone to promote lipid mobilisation, hepatic glucose production and an overall state of catabolism. With further research, the insulin tolerance test may be a useful tool to identify cows with greater growth hormone secretory response and increased milk production or persistency.

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