Changes in somatotropin and thyrotropin secretory patterns in aging rats

Rodolfo G. Goya, Kathleen L. Quigley, Sumio Takahashi, Yolanda E. Sosa, Joseph Meites

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

In order to clarify whether pituitary enlargement influences the secretory patterns of growth hormone (GH) and thyrotropin (TSH) in old rats, we studied the correlation between pituitary weight and plasma levels of GH and TSH in Sprague-Dawley rats of different age and sex. Young female (3-4 months; YF), old female (25 months; OF), and senescent female (33-35 months; SF) rats and young male (3-4 months; YM) and old male (24-26 months; OM) rats carrying chronic intraatrial cannulas were used. Sequential blood samples were removed through the cannulas while the animals remained conscious and undisturbed. Plasma TSH and GH as well as serum thyroxine (T 4 ) and triiodothyronine (T 3 ) were measured by radioimmunoassay. At two years of age, both males and females showed a consistent decline in GH pulse amplitude without change in trough levels. By 33-35 months of age, females showed a reversal in the previous pattern of change for GH secretion: pulse amplitude, trough levels, and mean plasma GH increased significantly with respect to the old females. The correlation between mean plasma GH and anterior pituitary (AP) weight was positive and significant (p<0.01) for females but nonsignificant for males. Old and senescent rats showed significantly lower serum T 4 , but not T 3 , than young animals while plasma TSH increased with age in both sexes. The present results show for the first time that senescent females hypersecrete GH and suggest that the age-related alteration of TSH secretion in rats may be due to the low levels of T 4 present in the aged animals. The correlation analysis shows that pituitary enlargement is in general associated with increased secretion of both GH and TSH in senescent female rats.

Original languageEnglish
Pages (from-to)625-630
Number of pages6
JournalNeurobiology of Aging
Volume11
Issue number6
DOIs
Publication statusPublished - Jan 1 1990
Externally publishedYes

Fingerprint

Thyrotropin
Growth Hormone
Weights and Measures
Triiodothyronine
Serum
Thyroxine
Radioimmunoassay
Sprague Dawley Rats

Keywords

  • Aging
  • Growth hormone
  • Pituitary enlargement
  • Secretory patterns
  • Thyrotropin

ASJC Scopus subject areas

  • Neuroscience(all)
  • Ageing
  • Clinical Neurology
  • Developmental Biology
  • Geriatrics and Gerontology

Cite this

Changes in somatotropin and thyrotropin secretory patterns in aging rats. / Goya, Rodolfo G.; Quigley, Kathleen L.; Takahashi, Sumio; Sosa, Yolanda E.; Meites, Joseph.

In: Neurobiology of Aging, Vol. 11, No. 6, 01.01.1990, p. 625-630.

Research output: Contribution to journalArticle

Goya, Rodolfo G. ; Quigley, Kathleen L. ; Takahashi, Sumio ; Sosa, Yolanda E. ; Meites, Joseph. / Changes in somatotropin and thyrotropin secretory patterns in aging rats. In: Neurobiology of Aging. 1990 ; Vol. 11, No. 6. pp. 625-630.
@article{e4777f9cf9c64484a240f364069bdf52,
title = "Changes in somatotropin and thyrotropin secretory patterns in aging rats",
abstract = "In order to clarify whether pituitary enlargement influences the secretory patterns of growth hormone (GH) and thyrotropin (TSH) in old rats, we studied the correlation between pituitary weight and plasma levels of GH and TSH in Sprague-Dawley rats of different age and sex. Young female (3-4 months; YF), old female (25 months; OF), and senescent female (33-35 months; SF) rats and young male (3-4 months; YM) and old male (24-26 months; OM) rats carrying chronic intraatrial cannulas were used. Sequential blood samples were removed through the cannulas while the animals remained conscious and undisturbed. Plasma TSH and GH as well as serum thyroxine (T 4 ) and triiodothyronine (T 3 ) were measured by radioimmunoassay. At two years of age, both males and females showed a consistent decline in GH pulse amplitude without change in trough levels. By 33-35 months of age, females showed a reversal in the previous pattern of change for GH secretion: pulse amplitude, trough levels, and mean plasma GH increased significantly with respect to the old females. The correlation between mean plasma GH and anterior pituitary (AP) weight was positive and significant (p<0.01) for females but nonsignificant for males. Old and senescent rats showed significantly lower serum T 4 , but not T 3 , than young animals while plasma TSH increased with age in both sexes. The present results show for the first time that senescent females hypersecrete GH and suggest that the age-related alteration of TSH secretion in rats may be due to the low levels of T 4 present in the aged animals. The correlation analysis shows that pituitary enlargement is in general associated with increased secretion of both GH and TSH in senescent female rats.",
keywords = "Aging, Growth hormone, Pituitary enlargement, Secretory patterns, Thyrotropin",
author = "Goya, {Rodolfo G.} and Quigley, {Kathleen L.} and Sumio Takahashi and Sosa, {Yolanda E.} and Joseph Meites",
year = "1990",
month = "1",
day = "1",
doi = "10.1016/0197-4580(90)90028-X",
language = "English",
volume = "11",
pages = "625--630",
journal = "Neurobiology of Aging",
issn = "0197-4580",
publisher = "Elsevier Inc.",
number = "6",

}

TY - JOUR

T1 - Changes in somatotropin and thyrotropin secretory patterns in aging rats

AU - Goya, Rodolfo G.

AU - Quigley, Kathleen L.

AU - Takahashi, Sumio

AU - Sosa, Yolanda E.

AU - Meites, Joseph

PY - 1990/1/1

Y1 - 1990/1/1

N2 - In order to clarify whether pituitary enlargement influences the secretory patterns of growth hormone (GH) and thyrotropin (TSH) in old rats, we studied the correlation between pituitary weight and plasma levels of GH and TSH in Sprague-Dawley rats of different age and sex. Young female (3-4 months; YF), old female (25 months; OF), and senescent female (33-35 months; SF) rats and young male (3-4 months; YM) and old male (24-26 months; OM) rats carrying chronic intraatrial cannulas were used. Sequential blood samples were removed through the cannulas while the animals remained conscious and undisturbed. Plasma TSH and GH as well as serum thyroxine (T 4 ) and triiodothyronine (T 3 ) were measured by radioimmunoassay. At two years of age, both males and females showed a consistent decline in GH pulse amplitude without change in trough levels. By 33-35 months of age, females showed a reversal in the previous pattern of change for GH secretion: pulse amplitude, trough levels, and mean plasma GH increased significantly with respect to the old females. The correlation between mean plasma GH and anterior pituitary (AP) weight was positive and significant (p<0.01) for females but nonsignificant for males. Old and senescent rats showed significantly lower serum T 4 , but not T 3 , than young animals while plasma TSH increased with age in both sexes. The present results show for the first time that senescent females hypersecrete GH and suggest that the age-related alteration of TSH secretion in rats may be due to the low levels of T 4 present in the aged animals. The correlation analysis shows that pituitary enlargement is in general associated with increased secretion of both GH and TSH in senescent female rats.

AB - In order to clarify whether pituitary enlargement influences the secretory patterns of growth hormone (GH) and thyrotropin (TSH) in old rats, we studied the correlation between pituitary weight and plasma levels of GH and TSH in Sprague-Dawley rats of different age and sex. Young female (3-4 months; YF), old female (25 months; OF), and senescent female (33-35 months; SF) rats and young male (3-4 months; YM) and old male (24-26 months; OM) rats carrying chronic intraatrial cannulas were used. Sequential blood samples were removed through the cannulas while the animals remained conscious and undisturbed. Plasma TSH and GH as well as serum thyroxine (T 4 ) and triiodothyronine (T 3 ) were measured by radioimmunoassay. At two years of age, both males and females showed a consistent decline in GH pulse amplitude without change in trough levels. By 33-35 months of age, females showed a reversal in the previous pattern of change for GH secretion: pulse amplitude, trough levels, and mean plasma GH increased significantly with respect to the old females. The correlation between mean plasma GH and anterior pituitary (AP) weight was positive and significant (p<0.01) for females but nonsignificant for males. Old and senescent rats showed significantly lower serum T 4 , but not T 3 , than young animals while plasma TSH increased with age in both sexes. The present results show for the first time that senescent females hypersecrete GH and suggest that the age-related alteration of TSH secretion in rats may be due to the low levels of T 4 present in the aged animals. The correlation analysis shows that pituitary enlargement is in general associated with increased secretion of both GH and TSH in senescent female rats.

KW - Aging

KW - Growth hormone

KW - Pituitary enlargement

KW - Secretory patterns

KW - Thyrotropin

UR - http://www.scopus.com/inward/record.url?scp=0025204502&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025204502&partnerID=8YFLogxK

U2 - 10.1016/0197-4580(90)90028-X

DO - 10.1016/0197-4580(90)90028-X

M3 - Article

C2 - 2280806

AN - SCOPUS:0025204502

VL - 11

SP - 625

EP - 630

JO - Neurobiology of Aging

JF - Neurobiology of Aging

SN - 0197-4580

IS - 6

ER -