Histofluorescence evaluation of sympathetic nerve fibers in hearts of developing rats exposed to ethanol during gestation.
Histofluorescence for catecholamines has been used to examine the ingrowth of the sympathetic innervation in the heart of control rats and rats exposed either pre- or perinatally to ethanol. In all groups, sympathetic innervation began in primary association with large blood vessels and, to a lesser extent, in the myocardial surface between 2 and 6 days of postnatal age. From day 9 onward, innervation progressed in density first in the atria and right ventricle. The deep muscle of the left ventricle was least innervated of all areas of the heart at all time periods examined. In pups exposed continuously to ethanol or withdrawn at birth, the innervation pattern and density were similar to controls, although slight qualitative differences may have occurred in the first two weeks of the postnatal period in the group exposed continuously to ethanol. The reported altered cardiac biochemical responses to sympathetic agents after pre- or perinatal exposure to ethanol did not appear to be associated with significant alterations in the growth of sympathetic nerve fibers into the heart. It is suggested that the alterations in the development of the cardiac sympathetic nervous system induced by ethanol probably occurs at the level of nerve terminals or adrenergic receptors.
D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D005453:Fluorescence; D005865:Gestational Age; D006321:Heart / Q000294:innervation*; D006651:Histocytochemistry; D009474:Neurons / Q000502:physiology*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013564:Sympathetic Nervous System / Q000378:metabolism*
D002395:Catecholamines; D000431:Ethanol