Document Detail


Dentate granule cells as a central cardioregulatory site in the rat.
MedLine Citation:
PMID:  7820590     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Dentate granule cells can be selectively destroyed by intrahippocampal injections of colchicine. This study evaluates the consequences of granule cell destruction on blood pressure regulation in the normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rat (SHR). Bilateral destruction of dentate granule cells at 6 weeks of age produced a significant increase in blood pressure in the WKY that lasted for approximately 3 weeks, and a biphasic effect (increase then decrease) in the SHR that resulted in a significant hypotensive period that persisted for 6 weeks. Granule cell destruction at 11 weeks produced a maximal hypertension in the SHR that preceded age-matched controls by 4 weeks, but produced only a small transient increase in WKY blood pressure. Dentate granule cells are the exclusive source of prodynorphin-derived peptides in the hippocampal formation and their synthesis is regulated by glucocorticoids. Evidence suggests glucocorticoids may be involved in the regulation of blood pressure and hypertension. We determined that chronic high levels of corticosterone significantly reduced hippocampal dynorphin B levels in normotensive Sprague-Dawley rats. In addition, we confirmed that naive SHRs also contain significantly lower levels of hippocampal dynorphin B. These results suggest (i) that dentate granule cells represent a discrete neural site that may exert a tonic inhibitory influence on blood pressure, (ii) that dentate granule cells are not required for the full expression of hypertension in the SHR, and (iii) that chronic high levels of corticosterone can reduce dynorphin B levels in the dentate granule cells of normotensive rats.
Authors:
T H Privette; J Q Wang; A J Ingenito; D M Terrian
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Brain research     Volume:  656     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  1994 Sep 
Date Detail:
Created Date:  1995-02-14     Completed Date:  1995-02-14     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  295-301     Citation Subset:  IM    
Affiliation:
Department of Anatomy and Cell Biology, East Carolina University School of Medicine, Greenville, NC 27858-4354.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Aging / physiology
Animals
Blood Pressure* / drug effects
Colchicine / toxicity
Corticosterone / pharmacology
Dynorphins / metabolism
Endorphins / metabolism
Hippocampus / cytology,  drug effects,  physiology*
Hypertension / physiopathology*
Male
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Rats, Sprague-Dawley
Chemical
Reg. No./Substance:
0/Endorphins; 50-22-6/Corticosterone; 64-86-8/Colchicine; 74913-18-1/Dynorphins; 83335-41-5/rimorphin

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


Previous Document:  Potassium currents in epilepsy: effects of the epileptogenic agent pentylenetetrazol on a cloned pot...
Next Document:  Serotonergic inhibition of extracellular glutamate in the suprachiasmatic nuclear region assessed us...