The Effects of Pharmacological Manipulations That Influence Vagal Control of the Heart on Heart Period, Heart Period Variability and Respiration in Rats

摘要: Changes in heart period (HP), heart-period variance (HPV), and the respiratory component of HPV freely moving rats were examined following pharmacological manipulations known to influence vagal control heart. Spectral analysis was used quantify associated with respiration which is proposed be sensitive influences on The described by a statistic, V, sum spectral densities spectrum across band frequencies normal respiration. Vagal tone reflexively enhanced phenylephrine or peripherally blocked atropine. Phenylephrine produced biphasic changes HP increases lasting from 0.5 2 hrs. Atropine resulted significant decreases HP, V. These immediate sustained throughout experiment, although there signiflcant linear their initial post-injection values. In saline condition, increased linearly time. Results discussed terms non-vagal It suggested that, while all three variables are altered heart, V seems influenced less than HPV.