Synthetic hpGRF 1–40 stimulates growth hormone and inhibits prolactin secretion in normal children and children with isolated growth hormone deficiency

Pintor, C.; Fanni, Victor Silvestre Soares; Loche, Sandro; Locatelli, Vittorio; Cella, Silvano G.; Villa, Felipe Miguel de la; Minuto, Francesco; Corda, R.; Müller, Eugenio E.

doi:10.1016/0196-9781(83)90092-x

Cited by 33 publications

(14 citation statements)

References 9 publications

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“…One of the major problems of the stimulation tests lies in the great number of false-negative responses frequently observed also in normal children [8,9]. Even the GHRH test is not useful in this regard, since great in ter-and intra-individual variabilities as well as false-nega tive responses are commonly found [10][11][12]. The suggest ed reason for this variability has been the varying soma tostatin tone, which may influence the somatotroph re sponse to the exogenously administered neuropeptide [ 13,14] .…”

Section: Discussionmentioning

confidence: 99%

Growth Hormone (GH) Response to Combined Pyridostigmine and GH-Releasing Hormone Administration in Patients with Prader-Labhard-Willi Syndrome

et al. 1993

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We evaluated the GH response to combined administration of pyridostigmine (PD), a cholinergic agonist, and GH-releasing hormone (GHRH) (60 mg PD given orally 60 min before the GHRH bolus) as well as baseline IGF-I concentrations in 10 patients (5 males and 5 females, age 6.0-24 years) with Prader-Labhard-Willi (PLW) syndrome, 8 prepubertal obese children (4 males and 4 females, age 5.6-12.0 years) and 9 prepubertal short normal children (7 males and 2 females, age 8.0-12.8 years). Mean GH responses to PD + GHRH were significantly lower (p < 0.0001) in the PLW patients (13.8 ± 3.3 µg/l) than in the short normal children (52.2 ± 9.0 µg/l) and similar to those of the obese children (14.3 ± 3.2 µg/l). Mean serum IGF-I levels were significantly lower (p < 0.05) in the PLW patients (117.5 ± 26.4 µg/l) than in the obese (329.3 ± 88.0 µg/l) and the short normal children (214.3 ± 38.3 µg/l). Two of the PLW patients had absent GH responses to PD + GHRH associated with subnormal IGF-I concentrations, indicating pituitary GH deficiency. When these 2 cases were excluded from the statistical calculation, mean peak GH responses to PD + GHRH remained significantly lower (p < 0.0001) in the PLW patients (17.1 ± 3.0 µg/l), while their mean serum IGF-I concentrations (143.4 ± 71.5 µg/l) were not significantly different from those of the other two groups. These results indicate that patients with the PLW syndrome have a reduced or absent GH secretory reserve associated in some cases with low levels of IGF-I. Whether these findings are involved in the pathogenesis of their short stature remains to be confirmed.

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Section: Discussionmentioning

confidence: 99%

Growth Hormone (GH) Response to Combined Pyridostigmine and GH-Releasing Hormone Administration in Patients with Prader-Labhard-Willi Syndrome

et al. 1993

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“…The effect of GRF on pituitary hormone secretion has generally been reported to be highly specific for GH in normal individuals [14,38,40,49], In hypopituitarism, how ever, contradictory data have been reported on the effect of GRF on PRL secretion: a doubling of the basal plasma PRL concentra tion was observed in adult hypopituitary pa tients 15 min after a dose of 10 pg/kg of GRF-40 [6] and a smaller increase was re ported after 5 pg/kg of GRF-44 in patients with multiple pituitary hormone deficiencies [42], In contrast, a PRL-lowering effect was noted in a small group of hypopituitary chil dren after 1 pg/kg of GRF-40 [34]. Likewise, in vitro studies on the effect of GRF on PRL mRNA concentration [15] and on PRL re lease from cultured rat [15] or sheep [24] pituitary cells are contradictory.…”

Section: Discussionmentioning

confidence: 99%

Effect of Growth Hormone-Releasing Factor on Plasma Growth Hormone, Prolactin and Somatomedin C in Hypopituitary and Short Normal Children

Vliet

Bosson²,

Robyn

et al. 1985

Horm Res

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We studied the effect of a single intravenous bolus of 0.5 µg/kg of growth hormone-releasing factor (GRF) on plasma GH, prolactin (PRL) and somatomedin C (SMC) in 12 short normal children and 24 patients with severe GH deficiency (GHD), i.e. GH < 5 ng/ml after insulin and glucagon tolerance tests. GRF elicited an increase in plasma GH in both short normal and GHD children. The mean GH peak was lower in the GHD than in the short normal children (8.2 ± 2.5 vs. 39.2 ± 5.1 ng/ml, p < 0.001). In the GHD patients (but not in the short normals) there was a negative correlation between bone age and peak GH after GRF (r = -0.58, p < 0.005); GH peaks within the normal range were seen in 5 out of 8 GHD children with a bone age < 5 years. In the short normal children, GRF had no effect on plasma PRL, which decreased continuously between 8.30 and 11 a.m. (from 206 ± 22 to 86 ± 10 µU/ml, p < 0.005), a reflection of its circadian rhythm. In the majority of the GHD patients, PRL levels were higher than in the short normal children but had the same circadian rhythm, except that a slight increase in PRL was observed 15 min after GRF; this increase in PRL was seen both in children with isolated GHD and in those with multiple hormone deficiencies; it did occur in some GHD patients who had no GH response to GRF. Serum SMC did not change 24 h after GRF in the short normal children. We conclude that: (1) in short normal children: (a) the mean GH response to a single intravenous bolus of 0.5 µg/kg of GRF is similar to that reported in young adults and (b) GRF has no effect on PRL secretion; (2) in GHD patients: (a) normal GH responses to GRF are seen in patients with a bone age < 5 years and

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“…Recent availability of peptides with growth hormone releasing factor (GRF) activity from human pancreatic tumours [14,20] has allowed testing of pituitary growth hormone (GH) reserves in both normal and GH-deficient children [7,13,18,21,23]. In a previous study in seven children with isolated GH-deficiency (IGHD), human pancreatic GRF (hpGRF-40) at the dose of 1.0 pg/kg, stimulated GH release, though to a lesser extent than in normal children, indicating that pituitary somatotrophs were still functional and that an absolute or relative defect in hypothalamic GRF function was present [18].…”

Section: Introductionmentioning

confidence: 99%

Growth hormone response to hpGRF-40 in different forms of growth retardation and endocrine-metabolic diseases

et al. 1986

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The effect of one of the new human pancreatic growth hormone releasing factors (hpGRFs) was assessed in children or young adults with different forms of growth retardation or endocrine-metabolic diseases. Intravenously administered synthetic hpGRF-40 (1 microgram/kg) induced a clear-cut and prompt rise in plasma growth hormone (GH) levels in 8 normal prepubertal children and a definite GH rise in 11 out of 14 children with isolated GH deficiency (IGHD) and one child with the Silver-Russel syndrome. In two out of three subjects with craniopharyngioma hpGRF-40 did not induce any plasma GH increase. In seven out of ten children with constitutional growth delay (CGD), hpGRF-40 induced a biphasic GH response, with a prompt small GH increment followed by a second, more consistent rise. Both in children with IGHD and with CGD the rise in plasma GH following hpGRF-40 was markedly lower than in controls. In children with CGD the GH response to hpGRF-40 was defective, despite the fact that in most of them the GH response to standard pharmacological stimuli was normal according to generally accepted criteria. hpGRF induced a small but sustained plasma GH rise in four hypothyroid subjects, while in three out of four children with idiopathic obesity the GH response to hpGRF was strikingly reduced. These data demonstrate that hpGRF is a potent stimulus of GH release in normal prepubertal children and a physiological means of investigating GH function in diseases associated with growth impairment.

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Synthetic hpGRF 1–40 stimulates growth hormone and inhibits prolactin secretion in normal children and children with isolated growth hormone deficiency

Cited by 33 publications

References 9 publications

Growth Hormone (GH) Response to Combined Pyridostigmine and GH-Releasing Hormone Administration in Patients with Prader-Labhard-Willi Syndrome

Growth Hormone (GH) Response to Combined Pyridostigmine and GH-Releasing Hormone Administration in Patients with Prader-Labhard-Willi Syndrome

Effect of Growth Hormone-Releasing Factor on Plasma Growth Hormone, Prolactin and Somatomedin C in Hypopituitary and Short Normal Children

Growth hormone response to hpGRF-40 in different forms of growth retardation and endocrine-metabolic diseases

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