Is there a place for urinary growth hormone measurement?

1993 ◽  
Vol 128 (3) ◽  
pp. 197-201 ◽  
Author(s):  
Maria N Moreira-Andrés ◽  
Francisco J Cañizo ◽  
Federico Hawkins
Keyword(s):  
Growth Hormone ◽  
Screening Method ◽  
Small Sample ◽  
Point Of View ◽  
Intrasubject Variability ◽  
Gh Secretion ◽  
Lack Of Information ◽  
Low Levels ◽  
Plasma Gh ◽  
Serum Gh

The evaluation of growth hormone (GH) secretion is an important problem in pediatric endocrine practice. The diagnosis of GH insufficiency is based on the finding of a "blunted" GH response to GH provocative tests or on the demonstration of a decreased endogenous secretion. From a practical point of view, these methods are uncomfortable, expensive and time consuming. Recently, very sensitive specific assays to measure human GH in urine have been developed. We present a discussion of available data on these tests in order to estimate their role in the evaluation of a short or slowly growing child. The present available assays allow measuring very low levels of GH in a small sample of untreated urine. The main limitations of urinary GH measurement are the intrasubject variability, wide normal range, overlapping results in several GH secretory states and lack of information on GH pulsatility. However, most of these limitations also apply to other tests of GH secretion. The advantage of urinary GH tests is that they provide, in an easy procedure, information on serum GH concentration. There is good correlation between urinary and serum GH concentration and several findings suggest that urinary GH excretion reflects changes in plasma GH levels during the period of urine collection. Therefore, the usefulness of urinary GH measurement is that of a simpler and cheaper screening method for assessing integrated serum GH concentration in clinical practice.

Mechanism of impaired growth hormone secretion in patients with Cushing's disease

1992 ◽  
Vol 127 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Hideo Takahashi ◽  
Hiroshi Bando ◽  
Chenyu Zhang ◽  
Ryuichi Yamasaki ◽  
Shiro Saito
Keyword(s):  
Growth Hormone ◽  
Cushing’S Disease ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Cushing's Disease ◽  
Gh Secretion ◽  
Highly Sensitive ◽  
Low Levels ◽  
Plasma Gh ◽  
Observation Period

The function of the growth hormone-releasing hormone (GHRH)-growth hormone (GH) axis in Cushing's disease was studied by monitoring (a) the GH responses to GHRH loading and L-dopa loading, (b) the GHRH response to L-dopa loading, and (c) the daytime profiles of plasma GH concentration. GH release following GHRH and L-dopa was blunted in patients as compared to that in age-matched control subjects. However, GHRH release following L-dopa was similar in patients and controls. The plasma GH levels in four patients measured every 20 min by a highly sensitive immunoradiometric assay for GH showed pulsatile GH secretion at low levels during the observation period. These results indicate that GHRH release from the hypothalamus is preserved in patients with Cushing's disease, and support the hypothesis that glucocorticoid inhibits GH secretion by altering the hypothalamic somatostatin tone.

Mechanism of action of Hexarelin. I. Growth hormone-releasing activity in the rat

1996 ◽  
Vol 135 (4) ◽  
pp. 481-488 ◽  
Author(s):  
Antonio Torsello ◽  
Roberta Grilli ◽  
Marina Luoni ◽  
Margherita Guidi ◽  
Maria Cristina Ghigo ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Mechanism Of Action ◽  
Direct Action ◽  
Male Rats ◽  
Surgical Ablation ◽  
Adult Rats ◽  
Gh Secretion ◽  
Plasma Gh

Torsello A, Grilli R, Luoni M, Guidi M, Ghigo MC, Wehrenberg WB, Deghenghi R, Müller EE, Locatelli V. Mechanism of action of Hexarelin. I. Growth hormone-releasing activity in the rat. Eur J Endocrinol 1996;135:481–8. ISSN 0804–4643 We have reported Hexarelin (HEXA), an analog of growth hormone-releasing peptide 6 (GHRP-6), potently stimulates growth hormone (GH) secretion in infant and adult rats. This study was undertaken to further investigate Hexarelin's mechanisms of action. In 10-day-old pups, treatments with HEXA (80 μg/kg, b.i.d.) for 3–10 days significantly enhanced, in a time-related fashion, the GH response to an acute HEXA challenge. Qualitatively similar effects were elicited in pups passively immunized against growth hormone-releasing hormone (GHRH) from birth. In adult male rats, a 5-day pretreatment with HEXA (150 μg/kg, b.i.d.) did not enhance the effect of the acute challenge, and the same pattern was present after a 5-day pretreatment in male rats with surgical ablation of the mediobasal hypothalamus (MBH-ablated rats). In addition, in adult sham-operated rats, Hexarelin (300 μg/kg, iv) induced a GH response greater (p < 0.05) than that induced by GHRH (2 μg/kg, iv). However, in MBH-ablated rats 7 days after surgery, GHRH was significantly (p < 0.05) more effective than HEXA, and 30 days after surgery HEXA and GHRH evoked similar rises of plasma GH. Finally, the in vitro Hexarelin (10−6 mol/l) effect was transient while GHRH (10−8 mol/l) induced a longer lasting and greater GH release. Three different mechanisms, not mutually exclusive, are postulated for Hexarelin stimulation of GH secretion in vivo: a direct action on the pituitary, though of minor relevance; an indirect action that involves release of GHRH, of relevance only in adult rats; and an action through the release of a still unknown hypothalamic "factor", which in infant and adult rats elicits GH release acting sinergistically with GHRH. Antonio Torsello, Department of Pharmacology, via Vanvitelli 32, 20129 Milano, Italy

Estimation of growth hormone secretion rate: impact of kinetic assumptions intrinsic to the analytical approach

2001 ◽  
Vol 280 (1) ◽  
pp. R225-R232 ◽  
Author(s):  
Janneke G. Langendonk ◽  
Johannes D. Veldhuis ◽  
Jacobus Burggraaf ◽  
Rik C. Schoemaker ◽  
Adam F. Cohen ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Analytical Approach ◽  
Normal Weight ◽  
Secretion Rate ◽  
The Other ◽  
Upper Body ◽  
Metabolic Clearance ◽  
Obese Women ◽  
Gh Secretion ◽  
Plasma Gh

We compared four common mathematical techniques to determine daily endogenous growth hormone (GH) secretion rates from diurnal plasma GH concentration profiles in 24 women (16 upper- or lower-body obese and 8 normal-weight individuals). Two forms of deconvolution analysis and two techniques based on a priori determined GH clearance estimates were employed. Deconvolution analyses revealed significant differences in the 24-h GH secretion rate between normal-weight and upper-body obese women, whereas the other two techniques did not. Moreover, deconvolution analyses predicted that the reduction in mean plasma GH concentrations in upper-body obese women was accounted for by impaired GH secretion, whereas the other methods suggested that obesity increases GH metabolic clearance. Thus we infer that disparate conclusions concerning GH secretion can be drawn from the same primary data set. The different inferences likely reflect dissimilar kinetic assumptions and the particular limitations intrinsic to each analytical approach. Accordingly, we urge caution in the facile comparison of calculated GH secretion data in humans, especially when kinetic and secretion measurements are performed under different conditions. The most appropriate way to determine the GH secretion rate in humans must be balanced by the exact intent of the experiment and the acceptability of different assumptions in that context.

Effect of intravenous bovine growth hormone or human pancreatic growth hormone-releasing factor on milk production and plasma hormones and metabolites in sheep

1985 ◽  
Vol 105 (2) ◽  
pp. 189-196 ◽  
Author(s):  
I. C. Hart ◽  
P. M. E. Chadwick ◽  
S. James ◽  
A. D. Simmonds
Keyword(s):  
Growth Hormone ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Fat ◽  
Latin Square ◽  
Plasma Urea ◽  
Gh Secretion ◽  
Vehicle Treatment ◽  
Plasma Hormones ◽  
Plasma Gh

ABSTRACT Although it is well known that exogenous bovine GH (bGH) increases milk yield in ruminants it has not been possible to determine whether an increase in endogenous GH secretion has the same effect. The recent isolation of human pancreatic GH-releasing factor (hpGRF-44) has enabled this comparison of the effects of bGH and hpGRF-44 on milk production in sheep. Three pairs of Dorset ewes underwent three 4-day treatments according to a Latin square design. Treatment 1 involved: 2-hourly i.v. injections (∼ 3·0 ml) of bGH (15 μg/kg; 1·8 units/mg); treatment 2: 2-hourly i.v. injections (∼3·0 ml) of hpGRF-44 (0·6 μg/kg); treatment 3: 2-hourly i.v. injections (3·0 ml) of the vehicle. Treatment periods were separated by 10 days. Sheep were milked twice daily and the milk was analysed for fat, protein and lactose. Blood samples (5·0 ml) were taken before and at 15, 45, 75 and 100 min after every third injection throughout the 4 days. Plasma was analysed for insulin, glucose, urea and non-esterified fatty acids (NEFA). The changes in plasma GH stimulated by hpGRF-44 were consistent and repeatable throughout the 4 days of treatment. In comparison to the controls, treatment with hpGRF-44 and bGH significantly increased average plasma GH (μg/l) for the 4 days (control, 5·7±0·2 (s.e.m.); hpGRF-44, 12·3±0·4, P<0·001; bGH, 14·5±0·5, P<0·001), and this was accompanied by similar increases in milk yield (hpGRF-44, 26·7±2·6%, P<0·001; bGH, 30·7±2·9%, P<0·001) and the concentration of milk fat (g/kg) (control, 28·6±0·5; hpGRF-44, 33·2±0·5; bGH 34·8±1·5, P<0·01 for both treatments). The post-treatment decline in milk yield was much slower after hpGRF-44 than after bGH injections. Both treatments stimulated significant increases in the average concentrations of plasma insulin, glucose and NEFA, and plasma urea was significantly reduced by treatment with bGH only. It is concluded that raising endogenous GH secretion is equally as effective as exogenous bGH in stimulating milk production in sheep. J. Endocr. (1985) 105, 189–196

Effect of actively immunizing sheep against growth hormone-releasing hormone or somatostatin on spontaneous pulsatile and neostigmine-induced growth hormone secretion

1995 ◽  
Vol 144 (1) ◽  
pp. 83-90 ◽  
Author(s):  
E Magnan ◽  
L Mazzocchi ◽  
M Cataldi ◽  
V Guillaume ◽  
A Dutour ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Physiological Role ◽  
Gh Secretion ◽  
Igf I ◽  
Plasma Gh ◽  
Hypophysial Portal

Abstract The physiological role of endogenous circulating GHreleasing hormone (GHRH) and somatostatin (SRIH) on spontaneous pulsatile and neostigmine-induced secretion of GH was investigated in adult rams actively immunized against each neuropeptide. All animals developed antibodies at concentrations sufficient for immunoneutralization of GHRH and SRIH levels in hypophysial portal blood. In the anti GHRH group, plasma GH levels were very low; the amplitude of GH pulses was strikingly reduced, although their number was unchanged. No stimulation of GH release was observed after neostigmine administration. The reduction of GH secretion was associated with a decreased body weight and a significant reduction in plasma IGF-I concentration. In the antiSRIH group, no changes in basal and pulsatile GH secretion or the GH response to neostigmine were observed as compared to controls. Body weight was not significantly altered and plasma IGF-I levels were reduced in these animals. These results suggest that in sheep, circulating SRIH (in the systemic and hypophysial portal vasculature) does not play a significant role in pulsatile and neostigmine-induced secretion of GH. The mechanisms of its influence on body weight and production of IGF-I remain to be determined. Journal of Endocrinology (1995) 144, 83–90

Characterization of growth hormone release in response to external heating Comparison to exercise induced release

1984 ◽  
Vol 107 (3) ◽  
pp. 295-301 ◽  
Author(s):  
Stig Engkjær Christensen ◽  
Otto Lunde Jørgensen ◽  
Niels Møller ◽  
Hans Ørskov
Keyword(s):  
Growth Hormone ◽  
Body Temperature ◽  
Temperature Increase ◽  
Clinical Test ◽  
Fasting State ◽  
Gh Secretion ◽  
External Heating ◽  
Normal Males ◽  
Exercise Induced ◽  
Plasma Gh

Abstract. The effects of increases in body temperature on growth hormone (GH)-release were studied in 10 young normal males in the fasting state as well as postprandially. The temperature increase of one degree centigrade was attained by external heating using thermostatically controlled water blankets covered by heat-reflecting aluminium foil. The increase in plasma GH after heating was partially suppressed in the non-fasting state reaching a mean of 7.9 ± 3.5 (sem), ng/ml, range 1.0–36 ng/ml. In contrast all subjects exhibited higher increases, mean 18.3 ± 4.0 ng/ml, range 7–44 ng/ml, in response to heating when fasting. The results were compared in the same subjects to the plasma GH-responses obtained during exercise (450 kpm/min for 40 min) inducing a similar increase in body temperature of about one degree centrigrade. Nevertheless the response in plasma GH (8.4 ± 3.3 ng/ml, range 0.4–34 ng/ml) was smaller than obtained by the heat test despite a rate of temperature increase on exercise which was about twice as high. Furthermore, the same exercise performed in a cold room under circumstances which precluded any major rises in core temperature resulted in complete inhibition of GH-release. The results indicate that exercise per se does not stimulate GH-secretion, indeed it may inhibit the response expected to be evoked by the exercise-induced rise in temperature. Evidence is also presented that it is core and not cutaneous temperature which modulated GH release. The procedure used for inducing the rise in temperature and plasma GH may be used as a simple, acceptable and safe clinical test for GH-insufficiency.

Growth hormone responses to growth hormone-releasing factor (1–29) in euthyroid, hypothyroid and hyperthyroid rats

1986 ◽  
Vol 109 (1) ◽  
pp. 53-56 ◽  
Author(s):  
C. Dieguez ◽  
V. Jordan ◽  
P. Harris ◽  
S. Foord ◽  
M. D. Rodriguez-Arnao ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Releasing Factor ◽  
Time Points ◽  
Gh Secretion ◽  
Hormone Responses ◽  
Plasma Gh

ABSTRACT In order to investigate whether the impaired GH secretion associated with hypothyroidism and hyperthyroidism is due to a hypothalamic or a pituitary disorder, we have studied plasma GH responses to GH-releasing factor (1–29) (GRF) in euthyroid, hypothyroid and hyperthyroid rats. Hypothyroid rats showed a significant (P< 0·001) reduction in GH responses to GRF (5 μg/kg) at 5 min (350 ± 35 vs 1950 ±260 μg/l), 10 min (366±66 vs 2320 ± 270 μg/l) and 15 min after GRF injection (395 ± 72 vs 1420 ± 183 μg/l; means ± s.e.m.) compared with euthyroid rats. Hyperthyroid rats showed a significant (P<0·05) decrease in GH responses to 5 μg GRF/kg after 30 min (200±14 vs 325 ± 35 μg/l) but not at other time-points, or after the administration of 1 μg GRF/kg. These data indicate that in hypothyroidism and perhaps hyperthyroidism there is an alteration in the responsiveness of the somatotroph to GRF administration. J. Endocr (1986) 109, 53–56

Inhibition of foetal growth hormone (GH) and thyrotrophin (TSH) secretion after maternal administration of somatostatin

1984 ◽  
Vol 106 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Elio Roti ◽  
Giuseppe Robuschi ◽  
Alessandro Alboni ◽  
Rossella Emanuele ◽  
Lorenzo d' Amato ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cord Blood ◽  
Pregnant Women ◽  
Marked Decrease ◽  
Maternal Blood ◽  
Gh Secretion ◽  
Foetal Growth ◽  
Tsh Secretion ◽  
Maternal Administration ◽  
Serum Gh

Abstract. Somatostatin (SRIF) was infused (500 μg over 30 min) into 68 pregnant women during labour. As a control, saline was infused into 26 pregnant women. Maternal blood was obtained prior to the infusion and at delivery and cord blood was obtained at delivery. The subjects were divided into 4 groups based upon the interval of time from the termination of SRIF infusion and delivery. There was a marked decrease in cord blood thyrotrophin (TSH) from 0 to 180 min and in cord blood growth hormone (GH) from 0 to 120 min following SRIF infusion. SRIF infusion did not affect cord blood iodothyronine and thyroglobulin concentrations. SRIF administration induced a small but significant (P < 0.05) decrease in serum GH concentration but had no other effect on maternal hormone values. These studies strongly suggest that SRIF crosses the human placenta and transiently suppresses foetal anterior pituitary TSH and GH secretion.

scholarly journals Effects of gender on exercise-induced growth hormone release

1999 ◽  
Vol 87 (3) ◽  
pp. 1154-1162 ◽  
Author(s):  
Laurie Wideman ◽  
Judy Y. Weltman ◽  
Niki Shah ◽  
Shannon Story ◽  
Johannes D. Veldhuis ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Area Under The Curve ◽  
Interactive Effects ◽  
Men And Women ◽  
Gh Secretion ◽  
Exercise Condition ◽  
Calculated Mass ◽  
Exercise Induced ◽  
Serum Gh ◽  
Secretion Rates

We examined gender differences in growth hormone (GH) secretion during rest and exercise. Eighteen subjects (9 women and 9 men) were tested on two occasions each [resting condition (R) and exercise condition (Ex)]. Blood was sampled at 10-min intervals from 0600 to 1200 and was assayed for GH by chemiluminescence. At R, women had a 3.69-fold greater mean calculated mass of GH secreted per burst compared with men (5.4 ± 1.0 vs. 1.7 ± 0.4 μg/l, respectively) and higher basal (interpulse) GH secretion rates, which resulted in greater GH production rates and serum GH area under the curve (AUC; 1,107 ± 194 vs. 595 ± 146 μg ⋅ l−1⋅ min, women vs. men; P = 0.04). Compared with R, Ex resulted in greater mean mass of GH secreted per burst, greater mean GH secretory burst amplitude, and greater GH AUC (1,196 ± 211 vs. 506 ± 90 μg ⋅ l−1⋅ min, Ex vs. R, respectivley; P < 0.001). During Ex, women attained maximal serum GH concentrations significantly earlier than men (24 vs. 32 min after initiation of Ex, respectively; P = 0.004). Despite this temporal disparity, both genders had similar maximal serum GH concentrations. The change in AUC (adjusted for unequal baselines) was similar for men and women (593 ± 201 vs. 811 ± 268 μg ⋅ l−1⋅ min), but there were significant gender-by-condition interactive effects on GH secretory burst mass, pulsatile GH production rate, and maximal serum GH concentration. We conclude that, although women exhibit greater absolute GH secretion rates than men both at rest and during exercise, exercise evokes a similar incremental GH response in men and women. Thus the magnitude of the incremental secretory GH response is not gender dependent.

Somatostatin tonically inhibits growth hormone secretion in domestic fowl

1986 ◽  
Vol 111 (1) ◽  
pp. 91-97 ◽  
Author(s):  
S. Harvey ◽  
S.-K. Lam ◽  
T. R. Hall
Keyword(s):  
Growth Hormone ◽  
Domestic Fowl ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Passive Immunization ◽  
Inhibitory Effect ◽  
Gh Secretion ◽  
Basal Plasma ◽  
Plasma Gh

ABSTRACT Passive immunization of immature chickens with sheep somatostatin (SRIF) antiserum promptly increased the basal plasma GH concentration and augmented TRH-induced GH secretion. Although exogenous SRIF had no inhibitory effect on the basal GH concentration in untreated birds or birds pretreated with non-immune sheep serum, it suppressed the stimulatory effect of SRIF immunoneutralization on GH secretion. These results suggest that SRIF is physiologically involved in the control of GH secretion in birds, in which it appears to inhibit GH release tonically. J. Endocr. (1986) 111, 91–97

Sign in / Sign up

Export Citation Format

Share Document