Geer P G, Wang B C, Flora-Ginter G, Leadley R J, Goetz K L
Division of Experimental Medicine, St. Luke's Hospital, Kansas City, Missouri 64111.
Proc Soc Exp Biol Med. 1988 Mar;187(3):327-34. doi: 10.3181/00379727-187-42672.
An increase in atrial pressure has been shown to cause an increase in the concentration of atrial peptides (atriopeptin) in plasma. We therefore hypothesized that a reduction in atrial pressure would decrease the concentration of atriopeptin in plasma. In formulating this hypothesis we assumed that changes in the concentration of other circulating hormones or changes in cardiac nerve activity during hemorrhage would not affect the secretion of atriopeptin. To test the hypothesis, we bled sham-operated conscious dogs at a rate of 0.8 ml.kg-1.min-1 to decrease right and left atrial pressures. Hemorrhage was continued until a total of 30 ml of blood per kilogram body weight had been removed. Identical experiments were performed on conscious cardiac-denervated dogs. The concentration of plasma atriopeptin was decreased in each group of dogs after 10 ml of blood per kilogram of body weight had been removed, but the decrease achieved statistical significance only in the cardiac-denervated dogs. Further hemorrhage, however, produced no further decreases in circulating atriopeptin in either group even though atrial pressures continued to decline as more blood was removed. A comparison of the atriopeptin response to hemorrhage revealed no significant difference between the sham-operated and cardiac-denervated dogs, thus providing no evidence for a specific effect of cardiac nerves on atriopeptin secretion during hemorrhage. Our results demonstrate that the relationship between atrial pressure and plasma atriopeptin that has been observed repeatedly during atrial stretch is not evident during relatively slow, prolonged hemorrhage. There is, however, a small decline in circulating atriopeptin during the initial stage of hemorrhage that could be of biological significance.
业已表明，心房压力升高会导致血浆中心房肽（心钠素）浓度升高。因此，我们推测心房压力降低会使血浆中心房肽浓度降低。在提出这一假说时，我们假定出血期间其他循环激素浓度的变化或心脏神经活动的变化不会影响心钠素的分泌。为验证这一假说，我们以0.8毫升·千克⁻¹·分钟⁻¹的速率对假手术清醒犬进行放血，以降低左右心房压力。放血持续进行，直至每千克体重共放血30毫升。对清醒的心脏去神经犬进行了相同的实验。每组犬在每千克体重放血10毫升后，血浆心钠素浓度均有所降低，但仅在心脏去神经犬中，这种降低具有统计学意义。然而，进一步放血并未使两组犬的循环心钠素进一步降低，尽管随着更多血液被放出，心房压力持续下降。比较心钠素对出血的反应发现，假手术犬和心脏去神经犬之间无显著差异，因此没有证据表明心脏神经在出血期间对心钠素分泌有特定影响。我们的结果表明，在心房牵张期间反复观察到的心房压力与血浆心钠素之间的关系，在相对缓慢、持续时间较长的出血过程中并不明显。然而，在出血的初始阶段，循环心钠素会有小幅下降，这可能具有生物学意义。
