Pulsatile TSH secretion during 48-hour continuous TRH infusions

Mary Samuels, P. Henry, M. Luther, E. C. Ridgway

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Thyroid-stimulating hormone (TSH), like other anterior pituitary hormones, is normally secreted in a series of pulses over 24 h. However, the factors that control TSH pulse generation are unknown. We investigated the potential role of thyrotropin-releasing hormone (TRH) in TSH pulse generation by measuring TSH pulses during constant TRH infusions. Two groups of subjects were studied: five healthy subjects and five subjects with treated primary hypothyroidism and normal TSH levels. Each subject underwent four separate studies: (1) TSH levels were measured every 15 min over 24 h (baseline study). (2) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.1 μg/min (low dose TRH study). (3) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.5 μg/min (medium dose TRH study). (4) TSH levels were measured every 15 min over 48 h during TRH infusions at 1.0 μg/min (high dose TRH study). TSH pulses were located by cluster analysis. We found that constant TRH infusions at any of the doses utilized did not alter TSH pulse frequency in normal or treated hypothyroid subjects, although pulse amplitude increased. Normal subjects had lower TSH pulse amplitude than treated hypothyroid subjects at all TRH doses, perhaps due to slightly higher serum T3 levels. This suggests that, at least acutely, pulsatile input of TRH to the pituitary gland does not determine pulsatile TSH release. However, TRH may modulate TSH pulse amplitude.

Original languageEnglish (US)
Pages (from-to)201-206
Number of pages6
JournalThyroid
Volume3
Issue number3
StatePublished - 1993

Fingerprint

Thyrotropin-Releasing Hormone
Thyrotropin
Anterior Pituitary Hormones
Pituitary Gland
Hypothyroidism
Cluster Analysis

ASJC Scopus subject areas

  • Endocrinology

Cite this

Samuels, M., Henry, P., Luther, M., & Ridgway, E. C. (1993). Pulsatile TSH secretion during 48-hour continuous TRH infusions. Thyroid, 3(3), 201-206.

Pulsatile TSH secretion during 48-hour continuous TRH infusions. / Samuels, Mary; Henry, P.; Luther, M.; Ridgway, E. C.

In: Thyroid, Vol. 3, No. 3, 1993, p. 201-206.

Research output: Contribution to journalArticle

Samuels, M, Henry, P, Luther, M & Ridgway, EC 1993, 'Pulsatile TSH secretion during 48-hour continuous TRH infusions', Thyroid, vol. 3, no. 3, pp. 201-206.
Samuels M, Henry P, Luther M, Ridgway EC. Pulsatile TSH secretion during 48-hour continuous TRH infusions. Thyroid. 1993;3(3):201-206.
Samuels, Mary ; Henry, P. ; Luther, M. ; Ridgway, E. C. / Pulsatile TSH secretion during 48-hour continuous TRH infusions. In: Thyroid. 1993 ; Vol. 3, No. 3. pp. 201-206.
@article{0d31ae58a49c47d7bc352c5716679337,
title = "Pulsatile TSH secretion during 48-hour continuous TRH infusions",
abstract = "Thyroid-stimulating hormone (TSH), like other anterior pituitary hormones, is normally secreted in a series of pulses over 24 h. However, the factors that control TSH pulse generation are unknown. We investigated the potential role of thyrotropin-releasing hormone (TRH) in TSH pulse generation by measuring TSH pulses during constant TRH infusions. Two groups of subjects were studied: five healthy subjects and five subjects with treated primary hypothyroidism and normal TSH levels. Each subject underwent four separate studies: (1) TSH levels were measured every 15 min over 24 h (baseline study). (2) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.1 μg/min (low dose TRH study). (3) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.5 μg/min (medium dose TRH study). (4) TSH levels were measured every 15 min over 48 h during TRH infusions at 1.0 μg/min (high dose TRH study). TSH pulses were located by cluster analysis. We found that constant TRH infusions at any of the doses utilized did not alter TSH pulse frequency in normal or treated hypothyroid subjects, although pulse amplitude increased. Normal subjects had lower TSH pulse amplitude than treated hypothyroid subjects at all TRH doses, perhaps due to slightly higher serum T3 levels. This suggests that, at least acutely, pulsatile input of TRH to the pituitary gland does not determine pulsatile TSH release. However, TRH may modulate TSH pulse amplitude.",
author = "Mary Samuels and P. Henry and M. Luther and Ridgway, {E. C.}",
year = "1993",
language = "English (US)",
volume = "3",
pages = "201--206",
journal = "Thyroid",
issn = "1050-7256",
publisher = "Mary Ann Liebert Inc.",
number = "3",

}

TY - JOUR

T1 - Pulsatile TSH secretion during 48-hour continuous TRH infusions

AU - Samuels, Mary

AU - Henry, P.

AU - Luther, M.

AU - Ridgway, E. C.

PY - 1993

Y1 - 1993

N2 - Thyroid-stimulating hormone (TSH), like other anterior pituitary hormones, is normally secreted in a series of pulses over 24 h. However, the factors that control TSH pulse generation are unknown. We investigated the potential role of thyrotropin-releasing hormone (TRH) in TSH pulse generation by measuring TSH pulses during constant TRH infusions. Two groups of subjects were studied: five healthy subjects and five subjects with treated primary hypothyroidism and normal TSH levels. Each subject underwent four separate studies: (1) TSH levels were measured every 15 min over 24 h (baseline study). (2) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.1 μg/min (low dose TRH study). (3) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.5 μg/min (medium dose TRH study). (4) TSH levels were measured every 15 min over 48 h during TRH infusions at 1.0 μg/min (high dose TRH study). TSH pulses were located by cluster analysis. We found that constant TRH infusions at any of the doses utilized did not alter TSH pulse frequency in normal or treated hypothyroid subjects, although pulse amplitude increased. Normal subjects had lower TSH pulse amplitude than treated hypothyroid subjects at all TRH doses, perhaps due to slightly higher serum T3 levels. This suggests that, at least acutely, pulsatile input of TRH to the pituitary gland does not determine pulsatile TSH release. However, TRH may modulate TSH pulse amplitude.

AB - Thyroid-stimulating hormone (TSH), like other anterior pituitary hormones, is normally secreted in a series of pulses over 24 h. However, the factors that control TSH pulse generation are unknown. We investigated the potential role of thyrotropin-releasing hormone (TRH) in TSH pulse generation by measuring TSH pulses during constant TRH infusions. Two groups of subjects were studied: five healthy subjects and five subjects with treated primary hypothyroidism and normal TSH levels. Each subject underwent four separate studies: (1) TSH levels were measured every 15 min over 24 h (baseline study). (2) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.1 μg/min (low dose TRH study). (3) TSH levels were measured every 15 min over 48 h during TRH infusions at 0.5 μg/min (medium dose TRH study). (4) TSH levels were measured every 15 min over 48 h during TRH infusions at 1.0 μg/min (high dose TRH study). TSH pulses were located by cluster analysis. We found that constant TRH infusions at any of the doses utilized did not alter TSH pulse frequency in normal or treated hypothyroid subjects, although pulse amplitude increased. Normal subjects had lower TSH pulse amplitude than treated hypothyroid subjects at all TRH doses, perhaps due to slightly higher serum T3 levels. This suggests that, at least acutely, pulsatile input of TRH to the pituitary gland does not determine pulsatile TSH release. However, TRH may modulate TSH pulse amplitude.

UR - http://www.scopus.com/inward/record.url?scp=0027521339&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027521339&partnerID=8YFLogxK

M3 - Article

C2 - 8257859

AN - SCOPUS:0027521339

VL - 3

SP - 201

EP - 206

JO - Thyroid

JF - Thyroid

SN - 1050-7256

IS - 3

ER -