Document Detail


Thyrotropin-releasing hormone in the dorsal vagal complex stimulates pancreatic blood flow in rats.
MedLine Citation:
PMID:  16040141     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Central administration of thyrotropin-releasing hormone (TRH) enhanced pancreatic blood flow in animal models. TRH nerve fibers and receptors are localized in the dorsal vagal complex (DVC), and retrograde tracing techniques have shown that pancreatic vagal nerves arise from the DVC. However, nothing is known about the central sites of action for TRH to elicit the stimulation of pancreatic blood flow. Effect of microinjection of a TRH analog into the DVC on pancreatic blood flow was investigated in urethane-anesthetized rats. After measuring basal flow, a stable TRH analog (RX-77368) was microinjected into the DVC and pancreatic blood flow response was observed for 120 min by laser Doppler flowmetry. Vagotomy of the several portions, or pretreatment with atoropine methyl nitrate or N(G)-nitro-l-arginine-methyl ester was performed. Microinjection of RX-77368 (0.1-10 ng) into the left or right DVC dose-dependently increased pancreatic blood flow. The stimulation of pancreatic blood flow by RX-77368 microinjection was eliminated by the same side of cervical vagotomy as the microinjection site or subdiaphragmatic vagotomy, but not by the other side of cervical vagotomy. The TRH-induced stimulation of pancreatic blood flow was abolished by atropine or N(G)-nitro-l-arginine-methyl ester. These results suggest that TRH acts in the DVC to stimulate pancreatic blood flow through vagal-cholinergic and nitric oxide dependent pathways, indicating that neuropeptides may act in the specific brain nuclei to regulate pancreatic function.
Authors:
Masashi Yoneda; Manabu Goto; Kimihide Nakamura; Shiro Yokohama; Toru Kono; Masaya Tanamo; Tadahito Shimada; Hideyuki Hiraishi
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Regulatory peptides     Volume:  131     ISSN:  0167-0115     ISO Abbreviation:  Regul. Pept.     Publication Date:  2005 Nov 
Date Detail:
Created Date:  2005-09-27     Completed Date:  2005-11-23     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8100479     Medline TA:  Regul Pept     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  74-81     Citation Subset:  IM    
Affiliation:
Department of Gastroenterology, Dokkyo University School of Medicine, Kitakobayashi 880, Mibu, Tochigi 321-0293, Japan. yoneda@dokkyomed.ac.jp
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MeSH Terms
Descriptor/Qualifier:
Animals
Atropine / pharmacology
Blood Pressure / drug effects
Enzyme Inhibitors / pharmacology
Laser-Doppler Flowmetry
Male
Medulla Oblongata / anatomy & histology*
Microinjections
NG-Nitroarginine Methyl Ester / pharmacology
Pancreas / blood supply*
Parasympatholytics / pharmacology
Pyrrolidonecarboxylic Acid / analogs & derivatives,  pharmacology
Rats
Rats, Wistar
Regional Blood Flow* / drug effects
Thyrotropin-Releasing Hormone / administration & dosage,  analogs & derivatives,  metabolism*,  pharmacology
Vagotomy
Vagus Nerve / metabolism*
Chemical
Reg. No./Substance:
0/Enzyme Inhibitors; 0/Parasympatholytics; 24305-27-9/Thyrotropin-Releasing Hormone; 50903-99-6/NG-Nitroarginine Methyl Ester; 51-55-8/Atropine; 76820-40-1/L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide; 98-79-3/Pyrrolidonecarboxylic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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