Journal article
In Vitro Acetylcholine Biosynthesis in Normal and Failing Guinea Pig Hearts
Circulation research, Vol.36(4), pp.547-552
04/1975
DOI: 10.1161/01.RES.36.4.547
PMID: 163710
Abstract
Choline acetyltransferase activity, which is rate limiting in acetylcholine biosynthesis, was measured in the four heart chambers of guinea pigs subjected to (1) sham surgery, (2) constriction of the ascending aorta, (3) constriction of the descending thoracic aorta, and (4) constriction of the pulmonary artery. After 30 days when hypertrophy and heart failure were fully established, choline acetyltransferase was quantified in vitro by a radiochemical assay. In the sham-operated group, enzyme activity expressed in terms of unit weight of cardiac tissue was greatest in the right atrium and the right ventricle and lower in the left atrium and the left ventricle (3.62 ± 0.30, 2.96 ± 0.52, 1.64 ± 0.15, and 1.67 ± 0.22 nmoles/min g respectively). Enzyme activity was reduced (P < 0.05) in the right atria and the right ventricles of guinea pigs with constriction of the pulmonary artery (1.68 ± 0.37 and 1.31 ± 0.29 nmoles/min g, respectively). Enzyme activity also tended to be reduced in the left atria and the left ventricles of guinea pigs with constriction of the aorta. These changes represented a relative dilution of enzyme activity per unit weight but not an absolute depletion, since, choline acetyltransferase activity per ventricle was not reduced. The absence of significant changes in the total amount of the neuronal enzyme, choline acetyltransferase, per ventricle contrasted with the observed increases in the myocardial enzyme, carnitine acetyltransferase. These results confirm the presence of significant parasympathetic innervation of the ventricles as well as the atria but do not demonstrate alterations in parasympathetic neurotransmitter biosynthesis in hypertrophied and failing myocardium. The absence of absolute reductions in choline acetyltransferase activity in hypertrophied and failing ventricle contrasts strikingly with the previously reported reductions in tyrosine hydroxylase, which is rate limiting in sympathetic neurotransmitter biosynthesis.
Details
- Title: Subtitle
- In Vitro Acetylcholine Biosynthesis in Normal and Failing Guinea Pig Hearts
- Creators
- Robert Roskoski - Department of Biochemistry and the Cardiovascular Division, Department of Internal Medicine, University of Iowa College of Medicine, and the Veterans Administration Hospital, Iowa City, Iowa 52242Phillip SchmidHoward MayerFrancois Abboud
- Resource Type
- Journal article
- Publication Details
- Circulation research, Vol.36(4), pp.547-552
- DOI
- 10.1161/01.RES.36.4.547
- PMID
- 163710
- NLM abbreviation
- Circ Res
- ISSN
- 0009-7330
- eISSN
- 1524-4571
- Publisher
- American Heart Association, Inc
- Language
- English
- Date published
- 04/1975
- Academic Unit
- Molecular Physiology and Biophysics; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984025572602771
Metrics
20 Record Views