Growth hormone responses to continuous infusions of growth hormone-releasing hormone

M. C. Gelato, R. S. Rittmaster, O. H. Pescovitz, M. C. Nicoletti, W. E. Nixon, R. D'Agata, Donald (Lynn) Loriaux, G. R. Merriam

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The pattern of GH secretion during a continuous 4-h iv infusion of 1 μg/kg·h GH-releasing hormone (1-44)-NH2 (GHRH-44) or saline was examined in 15 adult men. There was prompt release of GH beginning within 20 min of starting the GHRH-44 infusions, reaching peak GH levels of 43 ± 11 (±SE) ng/ml within 60-90 min. This is similar to the peak GH level reached in men after a single 1 μg/kg GHRH iv bolus dose (34 ± 8 ng/ml). GH levels then fell progressively, but did not return to baseline during the GHRH infusions. After GHRH infusions, the response (Δ) to a 1 μg/kg GHRH bolus dose was markedly attenuated (ΔGH, 2.7 ± 0.9 ng/ml) compared to the response (ΔGH, 23 ± 3 ng/ml) after saline infusion. Dispersed rat pituicytes perifused with medium containing 10 nM GHRH-44 responded with an initial rapid rise in GH secretion, followed by a progressive decline, and after 150 min of continuous GHRH exposure, the response to pulses of an equal or higher (100 nM) GHRH concentration was blunted. These results indicate that the peak response to GHRH infusions is similar to that of maximally effective bolus doses; during infusions, the GH response is not sustained; and immediately after GHRH infusions, the response to previously effective bolus doses is reduced. These phenomena could reflect either receptor-mediated desensitization, the depletion of rapidly releasable GH stores, or both. A counterregulatory rise in hypothalamic somatostatin secretion is not necessary to produce these effects, since the same phenomenon occurs in vitro and in vivo.

Original languageEnglish (US)
Pages (from-to)223-228
Number of pages6
JournalJournal of Clinical Endocrinology and Metabolism
Volume61
Issue number2
StatePublished - 1985
Externally publishedYes

Fingerprint

Growth Hormone-Releasing Hormone
Growth Hormone
Hormones
Somatostatin
Rats

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

Cite this

Gelato, M. C., Rittmaster, R. S., Pescovitz, O. H., Nicoletti, M. C., Nixon, W. E., D'Agata, R., ... Merriam, G. R. (1985). Growth hormone responses to continuous infusions of growth hormone-releasing hormone. Journal of Clinical Endocrinology and Metabolism, 61(2), 223-228.

Growth hormone responses to continuous infusions of growth hormone-releasing hormone. / Gelato, M. C.; Rittmaster, R. S.; Pescovitz, O. H.; Nicoletti, M. C.; Nixon, W. E.; D'Agata, R.; Loriaux, Donald (Lynn); Merriam, G. R.

In: Journal of Clinical Endocrinology and Metabolism, Vol. 61, No. 2, 1985, p. 223-228.

Research output: Contribution to journalArticle

Gelato, MC, Rittmaster, RS, Pescovitz, OH, Nicoletti, MC, Nixon, WE, D'Agata, R, Loriaux, DL & Merriam, GR 1985, 'Growth hormone responses to continuous infusions of growth hormone-releasing hormone', Journal of Clinical Endocrinology and Metabolism, vol. 61, no. 2, pp. 223-228.
Gelato MC, Rittmaster RS, Pescovitz OH, Nicoletti MC, Nixon WE, D'Agata R et al. Growth hormone responses to continuous infusions of growth hormone-releasing hormone. Journal of Clinical Endocrinology and Metabolism. 1985;61(2):223-228.
Gelato, M. C. ; Rittmaster, R. S. ; Pescovitz, O. H. ; Nicoletti, M. C. ; Nixon, W. E. ; D'Agata, R. ; Loriaux, Donald (Lynn) ; Merriam, G. R. / Growth hormone responses to continuous infusions of growth hormone-releasing hormone. In: Journal of Clinical Endocrinology and Metabolism. 1985 ; Vol. 61, No. 2. pp. 223-228.
@article{23bdc1fa7f15438f8dfaa04a1fe1f32e,
title = "Growth hormone responses to continuous infusions of growth hormone-releasing hormone",
abstract = "The pattern of GH secretion during a continuous 4-h iv infusion of 1 μg/kg·h GH-releasing hormone (1-44)-NH2 (GHRH-44) or saline was examined in 15 adult men. There was prompt release of GH beginning within 20 min of starting the GHRH-44 infusions, reaching peak GH levels of 43 ± 11 (±SE) ng/ml within 60-90 min. This is similar to the peak GH level reached in men after a single 1 μg/kg GHRH iv bolus dose (34 ± 8 ng/ml). GH levels then fell progressively, but did not return to baseline during the GHRH infusions. After GHRH infusions, the response (Δ) to a 1 μg/kg GHRH bolus dose was markedly attenuated (ΔGH, 2.7 ± 0.9 ng/ml) compared to the response (ΔGH, 23 ± 3 ng/ml) after saline infusion. Dispersed rat pituicytes perifused with medium containing 10 nM GHRH-44 responded with an initial rapid rise in GH secretion, followed by a progressive decline, and after 150 min of continuous GHRH exposure, the response to pulses of an equal or higher (100 nM) GHRH concentration was blunted. These results indicate that the peak response to GHRH infusions is similar to that of maximally effective bolus doses; during infusions, the GH response is not sustained; and immediately after GHRH infusions, the response to previously effective bolus doses is reduced. These phenomena could reflect either receptor-mediated desensitization, the depletion of rapidly releasable GH stores, or both. A counterregulatory rise in hypothalamic somatostatin secretion is not necessary to produce these effects, since the same phenomenon occurs in vitro and in vivo.",
author = "Gelato, {M. C.} and Rittmaster, {R. S.} and Pescovitz, {O. H.} and Nicoletti, {M. C.} and Nixon, {W. E.} and R. D'Agata and Loriaux, {Donald (Lynn)} and Merriam, {G. R.}",
year = "1985",
language = "English (US)",
volume = "61",
pages = "223--228",
journal = "Journal of Clinical Endocrinology and Metabolism",
issn = "0021-972X",
publisher = "The Endocrine Society",
number = "2",

}

TY - JOUR

T1 - Growth hormone responses to continuous infusions of growth hormone-releasing hormone

AU - Gelato, M. C.

AU - Rittmaster, R. S.

AU - Pescovitz, O. H.

AU - Nicoletti, M. C.

AU - Nixon, W. E.

AU - D'Agata, R.

AU - Loriaux, Donald (Lynn)

AU - Merriam, G. R.

PY - 1985

Y1 - 1985

N2 - The pattern of GH secretion during a continuous 4-h iv infusion of 1 μg/kg·h GH-releasing hormone (1-44)-NH2 (GHRH-44) or saline was examined in 15 adult men. There was prompt release of GH beginning within 20 min of starting the GHRH-44 infusions, reaching peak GH levels of 43 ± 11 (±SE) ng/ml within 60-90 min. This is similar to the peak GH level reached in men after a single 1 μg/kg GHRH iv bolus dose (34 ± 8 ng/ml). GH levels then fell progressively, but did not return to baseline during the GHRH infusions. After GHRH infusions, the response (Δ) to a 1 μg/kg GHRH bolus dose was markedly attenuated (ΔGH, 2.7 ± 0.9 ng/ml) compared to the response (ΔGH, 23 ± 3 ng/ml) after saline infusion. Dispersed rat pituicytes perifused with medium containing 10 nM GHRH-44 responded with an initial rapid rise in GH secretion, followed by a progressive decline, and after 150 min of continuous GHRH exposure, the response to pulses of an equal or higher (100 nM) GHRH concentration was blunted. These results indicate that the peak response to GHRH infusions is similar to that of maximally effective bolus doses; during infusions, the GH response is not sustained; and immediately after GHRH infusions, the response to previously effective bolus doses is reduced. These phenomena could reflect either receptor-mediated desensitization, the depletion of rapidly releasable GH stores, or both. A counterregulatory rise in hypothalamic somatostatin secretion is not necessary to produce these effects, since the same phenomenon occurs in vitro and in vivo.

AB - The pattern of GH secretion during a continuous 4-h iv infusion of 1 μg/kg·h GH-releasing hormone (1-44)-NH2 (GHRH-44) or saline was examined in 15 adult men. There was prompt release of GH beginning within 20 min of starting the GHRH-44 infusions, reaching peak GH levels of 43 ± 11 (±SE) ng/ml within 60-90 min. This is similar to the peak GH level reached in men after a single 1 μg/kg GHRH iv bolus dose (34 ± 8 ng/ml). GH levels then fell progressively, but did not return to baseline during the GHRH infusions. After GHRH infusions, the response (Δ) to a 1 μg/kg GHRH bolus dose was markedly attenuated (ΔGH, 2.7 ± 0.9 ng/ml) compared to the response (ΔGH, 23 ± 3 ng/ml) after saline infusion. Dispersed rat pituicytes perifused with medium containing 10 nM GHRH-44 responded with an initial rapid rise in GH secretion, followed by a progressive decline, and after 150 min of continuous GHRH exposure, the response to pulses of an equal or higher (100 nM) GHRH concentration was blunted. These results indicate that the peak response to GHRH infusions is similar to that of maximally effective bolus doses; during infusions, the GH response is not sustained; and immediately after GHRH infusions, the response to previously effective bolus doses is reduced. These phenomena could reflect either receptor-mediated desensitization, the depletion of rapidly releasable GH stores, or both. A counterregulatory rise in hypothalamic somatostatin secretion is not necessary to produce these effects, since the same phenomenon occurs in vitro and in vivo.

UR - http://www.scopus.com/inward/record.url?scp=0021846243&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021846243&partnerID=8YFLogxK

M3 - Article

C2 - 3924946

AN - SCOPUS:0021846243

VL - 61

SP - 223

EP - 228

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

SN - 0021-972X

IS - 2

ER -