Affiliation:
1. Department of Pediatrics, University of Rochester, School of Medicine and Dentistry, New York 14642.
Abstract
Adjustment of myocardial mass to work load is a fundamental characteristic of the heart. We studied the effect of verapamil, a calcium channel blocker, on growth and function of chick embryonic ventricle. We treated stage 18 chick embryos with verapamil delivered to the extraembryonic vascular bed by a miniosmotic pump and compared them with saline-treated control and untreated embryos. At stages 24, 27, and 29, we measured ventricular pressure and dP/dt by a servo-null system, dorsal aortic stroke volume and dV/dt by pulsed-Doppler, and ventricular and embryo wet weights. Mean myocyte profile area was measured by digital planimetry technique, and cell growth response by DNA and protein assay. Verapamil treatment decreased ventricular pressure in experimental (P less than 0.05) compared with saline control and normal embryos; at stage 27, 1.59 +/- 0.21 vs. 2.17 +/- 0.05 and 2.35 +/- 0.08 (SE) mmHg, respectively. Mean dorsal aortic blood flow decreased in experimental (P less than 0.05) vs. control and normal embryos; at stage 27, 0.98 +/- 0.07 vs. 1.54 +/- 0.10 and 1.56 +/- 0.07 mm3/s, respectively. Stroke volume remained the same in all experimental, normal, and control embryos except at stage 29. Ventricular weight decreased in experimental (P less than 0.05) vs. control and normal embryos; at stage 27, 1.09 +/- 0.07 vs. 1.51 +/- 0.08 and 1.54 +/- 0.11 mg, respectively. Embryo weights, myocyte size, and cytoplasmic fractional volume were similar in all groups. Morphology of ventricles was normal. DNA was lower in experimental (P less than 0.05) compared with control and normal embryos.(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher
American Physiological Society
Subject
Physiology (medical),Cardiology and Cardiovascular Medicine,Physiology
Cited by
21 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献