Tarasiuk A, Sasson L, Sofer S
Soroka Medical Center, Department of Physiology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel.
J Basic Clin Physiol Pharmacol. 2000;11(2):127-42. doi: 10.1515/jbcpp.2000.11.2.127.
Scorpion sting may cause myocardial dysfunction in human victims, probably by increased O2 demand and decreased O2 supply. In dog, scorpion venom (SV) causes no myocardial dysfunction. Myocardium is probably protected by "autotransfusion" of blood from the spleen to the circulation, increasing coronary blood flow (CBF) and O2 delivery. We hypothesized that ligation of spleen vessels prior to injection of SV in dogs would prevent the autotransfusion of blood, thereby causing myocardial ischemia due to decreased CBF, simulating the hemodynamic pattern of human envenomation. We studied cardiac output (CO), CBF, left ventricular (LV) O2 delivery and contractility in 11 dogs injected with 0.07 mg/kg of SV (Leiurus quinquestriatus). Ligation of spleen vessels was performed on 6 of the 11 dogs prior to SV injection. 15 min after SV injection CO had increased by 186% in control dogs, while ligation of spleen vessels completely prevented CO elevation (p<0.001). In both groups, however, LV dp/dt increased by 400% and dp/dt/p by 170% (p<0.001). CBF increased by 350% and 550% in the spleen and control groups (p<0.001) respectively. This was associated with elevation of diastolic blood pressure and a decrease in coronary vascular resistance. LV O2 delivery increased (p<0.05) in both groups. At 60 minutes there was a decrease in CO, stroke work, and LV end systolic pressure in both groups, while LV contractility remained above baseline. Scorpion venom injection in dogs causes an initial increase in CO by auto-transfusion of blood from the spleen. Prevention of the autotransfusion does not preclude increases in CBF, O2 delivery and LV contractility.
蝎子蜇伤可能会导致人类受害者出现心肌功能障碍，这可能是由于氧气需求增加和供应减少所致。在狗身上，蝎毒（SV）不会导致心肌功能障碍。心肌可能受到从脾脏到循环系统的血液“自身输血”的保护，从而增加冠状动脉血流量（CBF）和氧气输送。我们推测，在给狗注射SV之前结扎脾血管会阻止血液的自身输血，从而由于CBF减少导致心肌缺血，模拟人类中毒的血流动力学模式。我们研究了11只注射了0.07 mg/kg SV（以色列金蝎）的狗的心输出量（CO）、CBF、左心室（LV）氧气输送和收缩性。在11只狗中的6只身上，在注射SV之前进行了脾血管结扎。注射SV后15分钟，对照狗的CO增加了186%，而结扎脾血管则完全阻止了CO的升高（p<0.001）。然而，在两组中，LV dp/dt均增加了400%，dp/dt/p增加了170%（p<0.001）。脾组和对照组的CBF分别增加了350%和550%（p<0.001）。这与舒张压升高和冠状动脉血管阻力降低有关。两组的LV氧气输送均增加（p<0.05）。60分钟时，两组的CO、每搏功和LV收缩末期压力均下降，而LV收缩性仍高于基线水平。给狗注射蝎毒会通过脾脏自身输血使CO最初增加。阻止自身输血并不排除CBF、氧气输送和LV收缩性的增加。
