Vias dopaminérgicas e somatostatinérgicas diminuem o TSH sérico em ratos portadores de carcinoma mamário Walker-256.

Translated title of the contribution: Dopaminergic and somatostatinergic pathways decrease serum thyrotropin in rats bearing the 256-Walker mammary carcinoma

Osmar Monte, Szulin Zyngier, Edna T. Kimura, Antonio C. Bianco

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The hypothalamus-pituitary-thyroid axis was studied in rats with the "low T(3) syndrome" caused by the implantation of the Walker-256 mammary carcinoma. Male adult rats were injected s.c. with 1 x 106 viable tumoral cells and killed 10 days later. The tumor development was associated with decreased thyroid activity characterized by a approximately 15% reduction in the nuclear area of the thyrocytes and 131I-thyroid uptake (down by approximately 50%), as well as about 70% lower serum levels of T4 and rTg. The functional thyroidal response to exogenous TSH was decreased in the tumor-bearing rats, as well as the rTSH secretion in response to TRH (50 microg/kg). To investigate the role of other hypothalamic neuromediators in this process, tumor-bearing rats received an i.v. injection of metoclopramide (5 mg/kg) and/or physostigmine (12.5 microg/kg), with or without concomitant stimulus with TRH. Each drug improved the rTSH response to TRH, which in the case of physostigmine, almost normalized. When both drugs were injected simultaneously the rTSH response to TRH returned to normal. Thus, in addition to the well known alterations in the extrathyroidal metabolism of thyroid hormones, TSH secretion is decreased in rats with the Walker-256 tumor, indicating a generalized reduction in the thyroid function.

Original languageUndefined/Unknown
Pages (from-to)253-264
Number of pages12
JournalArquivos brasileiros de endocrinologia e metabologia.
Volume49
Issue number2
StatePublished - Apr 1 2005

Fingerprint

Walkers
Thyrotropin
Breast Neoplasms
Thyroid Gland
Serum
Physostigmine
Neoplasms
Metoclopramide
Thyroid Hormones
Pharmaceutical Preparations
Hypothalamus
Injections

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism

Cite this

Vias dopaminérgicas e somatostatinérgicas diminuem o TSH sérico em ratos portadores de carcinoma mamário Walker-256. / Monte, Osmar; Zyngier, Szulin; Kimura, Edna T.; Bianco, Antonio C.

In: Arquivos brasileiros de endocrinologia e metabologia., Vol. 49, No. 2, 01.04.2005, p. 253-264.

Research output: Contribution to journalArticle

@article{44f09e06d2e44a4ca6256935dd68b52a,
title = "Vias dopamin{\'e}rgicas e somatostatin{\'e}rgicas diminuem o TSH s{\'e}rico em ratos portadores de carcinoma mam{\'a}rio Walker-256.",
abstract = "The hypothalamus-pituitary-thyroid axis was studied in rats with the {"}low T(3) syndrome{"} caused by the implantation of the Walker-256 mammary carcinoma. Male adult rats were injected s.c. with 1 x 106 viable tumoral cells and killed 10 days later. The tumor development was associated with decreased thyroid activity characterized by a approximately 15{\%} reduction in the nuclear area of the thyrocytes and 131I-thyroid uptake (down by approximately 50{\%}), as well as about 70{\%} lower serum levels of T4 and rTg. The functional thyroidal response to exogenous TSH was decreased in the tumor-bearing rats, as well as the rTSH secretion in response to TRH (50 microg/kg). To investigate the role of other hypothalamic neuromediators in this process, tumor-bearing rats received an i.v. injection of metoclopramide (5 mg/kg) and/or physostigmine (12.5 microg/kg), with or without concomitant stimulus with TRH. Each drug improved the rTSH response to TRH, which in the case of physostigmine, almost normalized. When both drugs were injected simultaneously the rTSH response to TRH returned to normal. Thus, in addition to the well known alterations in the extrathyroidal metabolism of thyroid hormones, TSH secretion is decreased in rats with the Walker-256 tumor, indicating a generalized reduction in the thyroid function.",
author = "Osmar Monte and Szulin Zyngier and Kimura, {Edna T.} and Bianco, {Antonio C.}",
year = "2005",
month = "4",
day = "1",
language = "Undefined/Unknown",
volume = "49",
pages = "253--264",
journal = "Archives of endocrinology and metabolism",
issn = "2359-3997",
publisher = "Segmento Farma Editores",
number = "2",

}

TY - JOUR

T1 - Vias dopaminérgicas e somatostatinérgicas diminuem o TSH sérico em ratos portadores de carcinoma mamário Walker-256.

AU - Monte, Osmar

AU - Zyngier, Szulin

AU - Kimura, Edna T.

AU - Bianco, Antonio C.

PY - 2005/4/1

Y1 - 2005/4/1

N2 - The hypothalamus-pituitary-thyroid axis was studied in rats with the "low T(3) syndrome" caused by the implantation of the Walker-256 mammary carcinoma. Male adult rats were injected s.c. with 1 x 106 viable tumoral cells and killed 10 days later. The tumor development was associated with decreased thyroid activity characterized by a approximately 15% reduction in the nuclear area of the thyrocytes and 131I-thyroid uptake (down by approximately 50%), as well as about 70% lower serum levels of T4 and rTg. The functional thyroidal response to exogenous TSH was decreased in the tumor-bearing rats, as well as the rTSH secretion in response to TRH (50 microg/kg). To investigate the role of other hypothalamic neuromediators in this process, tumor-bearing rats received an i.v. injection of metoclopramide (5 mg/kg) and/or physostigmine (12.5 microg/kg), with or without concomitant stimulus with TRH. Each drug improved the rTSH response to TRH, which in the case of physostigmine, almost normalized. When both drugs were injected simultaneously the rTSH response to TRH returned to normal. Thus, in addition to the well known alterations in the extrathyroidal metabolism of thyroid hormones, TSH secretion is decreased in rats with the Walker-256 tumor, indicating a generalized reduction in the thyroid function.

AB - The hypothalamus-pituitary-thyroid axis was studied in rats with the "low T(3) syndrome" caused by the implantation of the Walker-256 mammary carcinoma. Male adult rats were injected s.c. with 1 x 106 viable tumoral cells and killed 10 days later. The tumor development was associated with decreased thyroid activity characterized by a approximately 15% reduction in the nuclear area of the thyrocytes and 131I-thyroid uptake (down by approximately 50%), as well as about 70% lower serum levels of T4 and rTg. The functional thyroidal response to exogenous TSH was decreased in the tumor-bearing rats, as well as the rTSH secretion in response to TRH (50 microg/kg). To investigate the role of other hypothalamic neuromediators in this process, tumor-bearing rats received an i.v. injection of metoclopramide (5 mg/kg) and/or physostigmine (12.5 microg/kg), with or without concomitant stimulus with TRH. Each drug improved the rTSH response to TRH, which in the case of physostigmine, almost normalized. When both drugs were injected simultaneously the rTSH response to TRH returned to normal. Thus, in addition to the well known alterations in the extrathyroidal metabolism of thyroid hormones, TSH secretion is decreased in rats with the Walker-256 tumor, indicating a generalized reduction in the thyroid function.

UR - http://www.scopus.com/inward/record.url?scp=33645121987&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645121987&partnerID=8YFLogxK

M3 - Article

C2 - 16184254

AN - SCOPUS:33645121987

VL - 49

SP - 253

EP - 264

JO - Archives of endocrinology and metabolism

JF - Archives of endocrinology and metabolism

SN - 2359-3997

IS - 2

ER -