scholarly journals Circadian Variations in the Amplitude of Corticotropin-Releasing Hormone 41 (CRH41) Episodic Release Measured In Vivo in Male Rats: Correlations with Diurnal Fluctuations in Hypothalamic and Median Eminence CRH41 Contents

1993 ◽  
Vol 8 (4) ◽  
pp. 297-309 ◽  
Author(s):  
G. Ixart ◽  
P. Siaud ◽  
G. Barbanel ◽  
M. Mekaouche ◽  
L. Givalois ◽  
...  
Keyword(s):  
Median Eminence ◽  
Male Rats ◽  
Corticotropin Releasing Hormone ◽  
Circadian Variations ◽  
Releasing Hormone ◽  
Diurnal Fluctuations

scholarly journals Hypersecretion of corticotrophin-releasing hormone and arginine vasopressin in hypothyroid male rats as estimated with push-pull perfusion

1998 ◽  
Vol 156 (2) ◽  
pp. 395-400 ◽  
Author(s):  
A Tohei ◽  
G Watanabe ◽  
K Taya
Keyword(s):  
Drinking Water ◽  
Median Eminence ◽  
Arginine Vasopressin ◽  
Plasma Concentrations ◽  
Male Rats ◽  
Releasing Hormone ◽  
In Vivo Release ◽  
The Relationship ◽  
Acth Release

The relationship between hypothyroidism and disturbance of the hypothalamo-hypophysial-adrenal axis was investigated using adult male rats. Hypothyroidism was produced by administration of 4-methyl-2-thiouracil (thiouracil) in the drinking water for 2 weeks. Hypothyroidism decreased adrenal weights to 57% of controls and plasma concentrations of corticosterone to 48% of controls. The changes in the weight of adrenals recovered to control levels by administration of thyroxine. The pituitary responsiveness to corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) for ACTH release markedly increased in hypothyroid rats as compared with euthyroid rats. In vivo release of CRH and AVP in median eminence significantly increased in hypothyroid rats as compared with euthyroid rats. There were no significant differences in hypothalamic concentrations of CRH and AVP. These results indicate that hypothyroidism causes adrenal dysfunction directly and results in hypersecretion of ACTH mediated by increases in synthesis of CRH and AVP in the hypothalamus.

Effect of different types of stressors on peptide messenger ribonucleic acids in the hypothalamic paraventricular nucleus

1993 ◽  
Vol 128 (6) ◽  
pp. 485-492 ◽  
Author(s):  
Sandra Ceccatelli ◽  
Catello Orazzo
Keyword(s):  
Paraventricular Nucleus ◽  
Immobilization Stress ◽  
Thyrotropin Releasing Hormone ◽  
Hypothalamic Paraventricular Nucleus ◽  
Male Rats ◽  
Mrna Levels ◽  
Corticotropin Releasing Hormone ◽  
Ribonucleic Acids ◽  
Releasing Hormone ◽  
Different Types

Using in situ hybridization we have studied the effects of different types of stressors, such as ether, immobilization, cold and swimming, on the expression of several peptide messenger ribonucleic acids (mRNAs) in the hypothalamic paraventricular nucleus of adult male rats. Paraventricular nucleus sections were hybridized using synthetic oligonucleotide probes complementary to mRNA for corticotropin-releasing hormone, neurotensin, enkephalin and thyrotropin-releasing hormone. A clear upregulation of neurotensin mRNA was seen after ether and, to a lesser extent, after immobilization stress, whereas after the two other stressors neurotensin mRNA was undetectable, as in control rats. An increase in enkephalin mRNA was observed in a selective region of the dorsal part of the medioparvocellular subdivision of the paraventricular nucleus only after ether and immobilization stress. No significant changes were seen in corticotropin-releasing hormone and thyrotropin-releasing hormone mRNA levels in any of the experimental paradigms. The present results show selective changes for various peptide mRNAs in the paraventricular nucleus after various types of stress. Significant effects could be demonstrated only on neurotensin and enkephalin mRNA after ether and immobilization stress. This suggests that adaptive changes in the rate of synthesis, processing and transport of the peptide may develop over a longer period of time.

In vivo action of a new octadecaneuropeptide antagonist on neuropeptide Y and corticotropin-releasing hormone mRNA levels in rat

2005 ◽  
Vol 141 (2) ◽  
pp. 156-160 ◽  
Author(s):  
V. Compère ◽  
S. Li ◽  
J. Leprince ◽  
M.C. Tonon ◽  
H. Vaudry ◽  
...  
Keyword(s):  
Neuropeptide Y ◽  
Mrna Levels ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone

A stress-induced anxious state in male rats: Corticotropin-releasing hormone induces persistent changes in associative learning and startle reactivity

2005 ◽  
Vol 57 (8) ◽  
pp. 865-872 ◽  
Author(s):  
Richard J. Servatius ◽  
Kevin D. Beck ◽  
Roberta L. Moldow ◽  
Gabriel Salameh ◽  
Tara P. Tumminello ◽  
...  
Keyword(s):  
Associative Learning ◽  
Male Rats ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Anxious State

In vivo Release of Dopamine, Luteinizing Hormone-Releasing Hormone and Thyrotropin-Releasing Hormone in Male Rats Bearing a Prolactin-Secreting Tumor

1987 ◽  
Vol 46 (2) ◽  
pp. 110-116 ◽  
Author(s):  
James L. Voogt ◽  
Wim J. de Greef ◽  
Theo J. Visser ◽  
Jurien de Koning ◽  
Jan T.M. Vreeburg ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Thyrotropin Releasing Hormone ◽  
Male Rats ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
In Vivo Release

scholarly journals Effects of corticotropin-releasing hormone on locus coeruleus neurons in vivo: a microdialysis study using a novel bilateral approach

2001 ◽  
pp. 359-363 ◽  
Author(s):  
S Asbach ◽  
C Schulz ◽  
H Lehnert
Keyword(s):  
Locus Coeruleus ◽  
Fused Silica ◽  
Corticotropin Releasing Hormone ◽  
Release Of Noradrenaline ◽  
Releasing Hormone ◽  
Significant Prolongation ◽  
Bilateral Approach ◽  
Microdialysis Study ◽  
Na Release

OBJECTIVE: Stress-induced release of noradrenaline (NA) from locus coeruleus (LC) neurons is mainly regulated by corticotropin-releasing hormone (CRH). Tyrosine is a precursor of NA and plays an intriguing role in the regulation of NA release. DESIGN: We studied the effects of injecting CRH into the LC using a novel bilateral approach which relies on the mainly ipsilateral projections of LC neurons allowing stimulation of one hemisphere while using the other as control. To analyze the modification of the CRH effect, tyrosine was given intraperitoneally. A combination of CRH and its antagonist d-Phe was administered for validation of the specificity of CRH effects. METHODS: Wistar rats were used in all experiments. Injections were made through fused silica capillaries implanted into both LCs and microdialysis samples were collected bilaterally from the prefrontal cortex (PFM) every 20 min for 1 h before and 3 h after injections. The effects of LC stimulation were investigated by determining 3-methoxy-4-hydroxyphenylglycol (MHPG) in the dialysates. RESULTS: Following CRH injection into one LC and contralateral infusion of artificial cerebrospinal fluid (aCSF), MHPG levels, which are indicative of NA release, increased only in the ipsilateral PFM. These effects were blocked by d-Phe. Simultaneous administration of tyrosine i.p. led to a significant prolongation of MHPG release. CONCLUSIONS: These data provide the first physiological evidence of unilateral LC projections with the bilateral stimulation design proving to be a very valuable tool for the study of LC firing rate, to decrease number of animals and time expenditure. Prolongation of MHPG release after tyrosine supplementation is most likely due to increased NA synthesis.

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