Document Detail

Age-dependent overflow of endogenous norepinephrine from paraventricular hypothalamic nucleus of hypertensive rats.
MedLine Citation:
PMID:  8342657     Owner:  NLM     Status:  MEDLINE    
The relationship between age and central noradrenergic neuronal activity of the paraventricular hypothalamic nucleus (PVH) was examined in 7- to 10-, 12- to 14-, and 30- to 36-wk-old Sprague-Dawley (SD), Wistar-Kyoto (WKY), and spontaneously hypertensive rats (SHR). As an index of noradrenergic activity, endogenous norepinephrine (NE) overflow was assessed utilizing a miniaturized push-pull cannula assembly in unanesthetized freely moving rats. NE overlow under basal, 56 mM K+ stimulation, and in response to pressor/depressor drugs, were examined in all three strains at all ages. Significant increases in basal and K(+)-stimulated overflow of endogenous NE from the PVH were observed in all ages of SHR compared with normotensive controls with the greatest percent increase occurring during the development of hypertension in SHR. In addition, a reciprocal relationship exists with respect to blood pressure and overflow of NE from the PVH such that increases/decreases in blood pressure elicit decreases/increases in NE overflow in all strains at all ages examined. However, developing hypertensive SHR exhibited attenuated decreases in overflow of NE from the PVH compared with age-matched controls and established hypertensive SHR. These results suggest that noradrenergic pathways of the PVH contribute to the development and maintenance of arterial pressure hemostasis and that enhanced central noradrenergic neuronal activity is greatest during the development of hypertension in SHR.
J M Qualy; T C Westfall
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  265     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1993 Jul 
Date Detail:
Created Date:  1993-08-27     Completed Date:  1993-08-27     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H39-46     Citation Subset:  IM    
Department of Pharmacological and Physiological Science, St. Louis University Medical School, Missouri 63104.
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MeSH Terms
Aging / physiology*
Blood Pressure / physiology
Hypertension / chemically induced,  metabolism*,  physiopathology
Norepinephrine / metabolism*
Paraventricular Hypothalamic Nucleus / metabolism*
Potassium / pharmacology
Rats, Inbred SHR
Rats, Inbred WKY
Rats, Sprague-Dawley
Grant Support
Reg. No./Substance:
15078-28-1/Nitroprusside; 51-41-2/Norepinephrine; 59-42-7/Phenylephrine; 7440-09-7/Potassium

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

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