Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Podzuweit, T. et al.

Catecholamine/cyclic AMP/Ca2+ induces arrhythmias in the healthy pig heart.

Agents known to increase cAMP levels in the myocardium were infused subepicardially (focal infusion, 10 microliters/min) in healthy pigs (open chest). Noradrenaline (NA) (10(-5) M), adrenaline (10(-5) M), and isoproterenol (10(-6) M) (in 0.9% NaCl) induced arrhythmias infrequently, but in the presence of Ca2+ (2.5 X 10(-3) M CaCl2) they consistently induced arrhythmias--most commonly ventricular tachycardia--within 60 sec that were readily reversible on termination of infusion. N6,O2'-dibutyryl-cAMP (dbcAMP) and N6-monobutyryl-cAMP (mbcAMP) (5 X 10(-2) M each) produced arrhythmias lasting up to 1 hr with rather slow (up to 20 min) onset. Arrhythmias were induced by 8-Br-cAMP (5 X 10(-2) M) in the presence of inhibitor of cyclic nucleotide phosphodiesterase (3 X 10(-4) M Ro 7-2956) within 30 min. The NA/Ca2+ arrhythmias were abolished by isoptin, D 600, MnCl2 (each 10(-4) M) and beta adrenoceptor blockade (10(-5) M pindolol, 10(-4) propranolol; 10(-4) M D-propranolol was ineffective) but were not suppressed by tetrodotoxin (up to 10(-5) M). Arrhythmias induced by dbcAMP or mbcAMP were abolished by isoptin (10(-4) M) and MnCl2 (5 X 10(-4) M) but not propranolol (10(-4) M). The NA/Ca2+ arrhythmias were also abolished by carbamylcholine (10(-6) M). Acetylcholine (10(-4) M) was less effective. Arrhythmias were not precipitated by 0.9% NaCl, 2.5 X 10(-3) M CaCl2/0.9% NaCl, 5 X 10(-2) M N6-monobutyryl-2'-deoxy-cAMP (deoxy-mbcAMP) or 10(-1) M sodium butyrate. Analysis of myocardial tissue obtained from the NA/Ca2+ infusion site showed that cAMP was increased when ventricular tachycardia ensued. We conclude that the catecholamine/cAMP/Ca2+ system may play an important role in the genesis of arrhythimas, possibly by inducing automaticity in ventricular fibers through slow Ca2+ channels[1]

References

Catecholamine/cyclic AMP/Ca2+ induces arrhythmias in the healthy pig heart. Podzuweit, T., Louw, G.C., Shanley, B.C. Advances in myocardiology. (1980) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.