ID 111599
Title Alternative
TRH RELEASE MEASURED BY MICRODIALYSIS
Author
Okauchi, Yasuhiro The University of Tokushima
Takahashi, Hideo The University of Tokushima
Mizobuchi, Miki The University of Tokushima
Bando, Hiroshi The University of Tokushima KAKEN Search Researchers
Saito, Shiro The University of Tokushima
Keywords
Thyrotropin-releasing hormone (TRH)
Pulsatile secretion
Microdialysis
Hyperthyroidism
Content Type
Journal Article
Description
To measure the thyrotropin-releasing hormone (TRH) release from the hypothalamus in euthyroid and hyperthyroid states, we investigated the changes in TRH levels in the anterior pituitary of conscious male rats using an in vivo microdialysis technique. In the euthyroid rats (n = 18), TRH levels in the extracellular dialysates of the anterior pituitary varied from 1.0 to 101.0 pg/ml in a pulsatile fashion: 15.9 +/- 13.9 (mean +/- SD) pg/ml with 5.8 +/- 1.5 pulses/24 h. In the hyperthyroid rats (n = 5) who received L-thyroxine at 10 micrograms/100 g body weight for 7 days, TRH levels in the dialysates during 6 h was 3.6 +/- 1.7 pg/ml, and significantly lower (P < 0.05) than those of the control rats (15.5 +/- 14.1 pg/ml); the pulse frequency was unchanged. These findings demonstrated for the first time the existence of pulsatile TRH release from the hypothalamus, and showed that thyroid hormone inhibits TRH release by the reduction of pulse amplitude, but not of pulse frequency.
Journal Title
The Tokushima Journal of Experimental Medicine
ISSN
00408875
NCID
AA00864027
Publisher
School of Medicine, The University of Tokushima
Volume
43
Issue
3-4
Start Page
93
End Page
100
Published Date
1996-12-25
FullText File
language
eng
TextVersion
Publisher
departments
Medical Sciences