Vacca G, Battaglia A, Chiorboli E, Grossini E, Papillo B
Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia di Novara, Università di Torino, Italy.
Cardioscience. 1995 Jun;6(2):121-30.
Previous studies in anesthetized animals showed that distension of the stomach or the descending colon primarily caused decreases in mean coronary blood flow. Whether these responses occurred during systole or diastole was not investigated. The present work was planned to study the primary effects of the distension of the two viscera on phasic coronary blood flow in the anesthetized pig. In ten animals, the stomach and the descending colon were distended at constant volume by injecting warm Ringer solution into intravisceral balloons (0.8 and 0.25 l respectively) while preventing changes in heart rate and arterial blood pressure. Distensions of the stomach or the descending colon caused a decrease in mean coronary blood flow in each pig. However, the decrease elicited by gastric distension occurred only during diastole, while the decrease caused by descending colon distension involved both systolic and diastolic coronary blood flows. The same effects on phasic coronary blood flow were observed during experiments in which the decreases in mean coronary blood flow elicited by distension of the stomach or the descending colon were further augmented by adding the distension of the second viscerum. The results indicate that the coronary vasoconstriction caused by gastric distension mainly involves the vessels which supply the subendocardial layers of the myocardium, while that caused by descending colon distension also involves the vessels which supply the subepicardial layers. The vasoconstrictor effect on the subendocardial coronary circulation is enhanced by the combined distension of the two viscera.
以往在麻醉动物身上进行的研究表明，胃或降结肠扩张主要导致冠状动脉平均血流量减少。但未研究这些反应是发生在收缩期还是舒张期。本研究旨在探讨这两种内脏扩张对麻醉猪冠状动脉血流相位的主要影响。对10只动物，通过向内脏内气囊（分别为0.8升和0.25升）注入温林格液，在恒定容积下扩张胃和降结肠，同时防止心率和动脉血压发生变化。胃或降结肠扩张均使每只猪的冠状动脉平均血流量减少。然而，胃扩张引起的血流量减少仅发生在舒张期，而降结肠扩张引起的血流量减少则涉及收缩期和舒张期的冠状动脉血流。在实验中，当胃或降结肠扩张引起的冠状动脉平均血流量减少通过增加另一个内脏的扩张而进一步加重时，观察到对冠状动脉血流相位有相同的影响。结果表明，胃扩张引起的冠状动脉血管收缩主要涉及供应心肌心内膜下层的血管，而降结肠扩张引起的血管收缩还涉及供应心外膜下层的血管。两种内脏联合扩张可增强对心内膜下冠状动脉循环的血管收缩作用。
