Age-Related Changes in Catecholaminergic Nerve Fibers of Rat Heart and Coronary Vessels

Background: Age-related changes of catecholaminergic nerve fibers supplying the myocardium and the coronary vessels were studied in adult and in old rats. Objective: The purpose of this study was to investigate whether there are quantitative changes in myocardial and/or coronary catecholaminergic nerve fibers and related neurotransmitters. Methods: Samples of myocardium and/or coronary vessels were studied by means of glyoxylic acid induced fluorescence, aldehyde-induced fluorescence, and neuropeptide Y immunoreactivity. All morphological results were submitted to quantitative analysis of images. Biochemical dosage of proteins and of norepinephrine was also performed, and morphological data were compared with biochemical ones. Finally, all data were subjected to statistical analysis. Results: Our findings are indicative of an age-related decrease of all types of fluorescent sympathetic nerve fibers in rat heart and coronary arteries. Moreover, our data show that aging induces a strong decrease of norepinephrine levels in tissue homogenates of rat heart and coronary vessels. The majority of the catecholaminergic nerve fibers that show strong age-related changes are not contiguous with contractile cells of myocardium and/or of vascular wall. In fact, these fibers are located in adventitial (or epicardial) and in endothelial (or endocardial) layers. Conclusion: The decrease of the catecholaminergic innervation of heart and coronary vessels of old rats can be in close relationships to the poor cardiac and/or coronary functions observed in old animals.

[1]  M. A. Qayyum,et al.  Use of glyoxylic acid in the demonstration of autonomic nerve profiles , 1985, Experientia.

[2]  A. Björklund,et al.  The glyoxylic acid fluorescence histochemical method: a detailed account of the methodology for the visualization of central catecholamine neurons , 1974, Histochemistry.

[3]  R. Croll,et al.  Regional distribution and extrinsic innervation of intrinsic cardiac neurons in the guinea pig. , 1999, The Journal of comparative neurology.

[4]  R. Zigmond.  Regulation of tyrosine hydroxylase by neuropeptides. , 1998, Advances in pharmacology.

[5]  C. Marfurt,et al.  Immunohistochemical localization of tyrosine hydroxylase in corneal nerves , 1993, The Journal of comparative neurology.

[6]  G. Burnstock,et al.  An increase in the expression of neuropeptidergic vasodilator, but not vasoconstrictor, cerebrovascular nerves in aging rats , 1988, Brain Research.

[7]  F. Amenta,et al.  Age-related changes in the noradrenergic innervation of the coronary arteries in old rats: a fluorescent histochemical study. , 1988, Journal of the autonomic nervous system.

[8]  F. Amenta,et al.  The noradrenergic innervation of the vasa nervorum in old rats: a fluorescence histochemical study. , 1987, Journal of the autonomic nervous system.

[9]  G. Burnstock,et al.  Perivascular noradrenergic and peptide-containing nerves show different patterns of changes during development and ageing in the guinea-pig. , 1986, Journal of the autonomic nervous system.

[10]  G. Burnstock,et al.  Development, Aging, and Plasticity of Perivascular Autonomic Nerves , 1986 .

[11]  F. Sundler,et al.  Neuropeptide Y-like immunoreactivity in perivascular nerve fibres of the guinea-pig , 1985, Regulatory Peptides.

[12]  R. Santer.  Fluorescence histochemical observations on the adrenergic innervation of the cardiovascular system in the aged rat , 1982, Brain Research Bulletin.

[13]  G. Burnstock,et al.  Development and ageing of perivascular adrenergic nerves in the rabbit. A quantitative fluorescence histochemical study using image analysis. , 1982, Journal of the autonomic nervous system.

[14]  A. Torp,et al.  Fluorescence of catechol amines and related compounds condensed with formaldehyde , 1962, Brain Research Bulletin.

[15]  A. Oke,et al.  Liquid chromatographic analysis of catecholamines routine assay for regional brain mapping. , 1976, Life sciences.

[16]  G. Burnstock.  Innervation of vascular smooth muscle: histochemistry and electron microscopy. , 1975, Clinical and experimental pharmacology & physiology.

[17]  P. B. Goldberg,et al.  Changes in cardiac membranes as a function of age with particular emphasis on reactivity to drugs. , 1975, Advances in experimental medicine and biology.

[18]  W. Burkard,et al.  Variation of the norepinephrine metabolism of the rat heart with age. , 1965, Gerontologia.

[19]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[20]  E. Piette,et al.  A Textbook of Histology , 1936, The Indian Medical Gazette.

[21]  Alexander A. Maximow,et al.  A Textbook of Histology , 1935, The Indian Medical Gazette.