The Effect of Passive Opium Smoking on Cardiovascular Indices of Rabbits with Normal and Ischemic Hearts

Some Asian people believe that opium can protect the cardiovascular system. To assess this belief, we investigated the effect of passive opium smoking (POS) on cardiovascular indices in rabbits with ischemic and non-ischemic hearts. Rabbits (n = 43) were divided into control (CTL), short term opium (SO) and long term opium (LO) groups. SO and LO groups were exposed to opium smoking for 3 days and 4 weeks, respectively. ECG, blood pressure (BP), left ventricular pressure and cardiac troponin I levels were recorded. Isoproterenol (ISO) was injected to induce cardiac ischemia and after 4 h the above variables were measured along with cardiac histopathology assessment. All groups showed significant increments in troponin I level (P < 0.05) except the CTL group. This trend was more obvious in ISO-treated groups. Mean arterial pressure (MAP) significantly decreased in all groups (p< 0.05) except the LO group. Opium exposure attenuated ISO-induced myodegeneration but augmented tissue congestion and hemorrhage. In conclusion, higher troponin I serum level and ECG changes were found in passive opium smoking groups. This evidence is against the belief that opium can protect the cardiovascular system.