The timing of sympathetic innervation affects growth of myocardium
in oculo.
Love, Timothy C., and Diane C. Tucker.
Departments of Psychology and Physiology, Neurobiology Research
Center, University of Alabama at Birmingham, Birmingham, AL 35294
APStracts 2:0032H, 1995.
The effects of sympathetic innervation on myocardial growth during the
proliferative and hypertrophic phases of cardiac growth were examined
using embryonic day 12 whole hearts or ventricles cultured in the
anterior eye chamber of adult rats for 8 weeks. Sympathetic
innervation of whole heart and ventricular grafts was prevented by
removing the superior cervical ganglion 1 week prior to grafting, or
was limited to the cellular proliferation phase of growth by superior
cervical ganglionectomy after grafts had been in oculo for 4 weeks.
Grafts in sympathetically innervated eye chambers were significantly
larger than grafts in eye chambers denervated at 4 weeks and grafts
in eye chambers sympathectomized 1 week prior to grafting.
Innervation of grafts was delayed until 5-6 weeks in oculo by crushing
the internal carotid nerve. Delayed innervation produced grafts that
were as large as those in innervated eye chambers. Together, these
experiments suggest that the effects of sympathetic innervation on
myocardial growth in oculo are most apparent during the second 4 weeks
in oculo (i.e, during the cellular enlargement phase of growth).
Received 2 September 1993; accepted in final form 12 January
1995.
APS Manuscript Number H0789-3.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 February 1995.