Document Detail


In vivo fluorescence microscopy of blood flow in mouse pancreatic islets: adrenergic effects in lean and obese-hyperglycemic mice.
MedLine Citation:
PMID:  3900643     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The microcirculation in the islets of Langerhans was examined by fluorescence microscopy in living mice injected with fluorescent dextran. The islet capillary network was denser and more tortuously arranged in obese-hyperglycemic (ob/ob) mice than in lean controls. Injection of norepinephrine (0.5-4.0 micrograms/kg body wt) immediately led to a pronounced inhibition of islet blood flow in ob/ob mice. In experiments with lean mice less striking effects were seen. With as high a dose as 20 micrograms norepinephrine/kg body wt only a slight retardation and very brief stop of the flow occurred. The inhibition in ob/ob mice was blocked by phentolamine, indicating that the norepinephrine-induced inhibition was mediated by alpha-adrenoceptors. The alpha-2-adrenoceptor agonist, clonidine, had no effect on islet blood flow, suggesting that the effect of norepinephrine was due to alpha-1-adrenoceptor stimulation. It is concluded that in the living animal norepinephrine inhibits insulin secretion from the pancreas by a twofold mechanism involving inhibition of exocytosis (alpha-2-receptors on the beta-cells) as well as retardation of blood flow (alpha-1-receptors on blood vessels).
Authors:
P Rooth; K Grankvist; I B Täljedal
Related Documents :
1553373 - Dissociation between the blood flow response of transplanted pancreatic islets and that...
14527913 - Intra-arterial infusion chemotherapy with angiotensin-ii for locally advanced and nonre...
8917183 - Cerebral hypoperfusion in orthostatic hypotension with globally denervated myocardium.
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Microvascular research     Volume:  30     ISSN:  0026-2862     ISO Abbreviation:  Microvasc. Res.     Publication Date:  1985 Sep 
Date Detail:
Created Date:  1985-11-14     Completed Date:  1985-11-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0165035     Medline TA:  Microvasc Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  176-84     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Clonidine / pharmacology*
Female
Islets of Langerhans / anatomy & histology,  blood supply*,  drug effects
Mice
Mice, Obese
Microscopy, Fluorescence
Norepinephrine / pharmacology*
Phentolamine / pharmacology*
Regional Blood Flow / drug effects
Chemical
Reg. No./Substance:
4205-90-7/Clonidine; 50-60-2/Phentolamine; 51-41-2/Norepinephrine

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


Previous Document:  Isolation of genes from Candida albicans by complementation in Saccharomyces cerevisiae.
Next Document:  Characterization of pathogenic constituents of Cryptococcus neoformans strains.