The effect of passive opium smoking on cardiovascular indices of rabbits with normal and ischemic hearts

Abstract

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.

Keywords: Opium smoking; cardiac ischemia; cardiac troponin I; histopathology..

Fig. (1)

Basal and 4^th h of mean arterial pressure (MAP) in different animal groups. Values are means ± SD. n= 6-8; CTL, control; SO, short opium; LO, long opium; ISO, isoproterenol. * P < 0.05 compared with relative basal level.

Fig. (2)

Changes in Max dp/dt from basal levels during 4 h of experiment in different animal groups. Values are means ± SD. n= 6-8; CTL, control; SO, short opium; LO, long opium; ISO, isoproterenol.

Fig. (3)

Basal and 4th h plasma cardiac Troponin I levels in animal groups. Values are means ± SD. n= 6-8; CTL, control; SO, short opium; LO, long opium; ISO, isoproterenol. * P < 0.05 and ** P < 0.01 compared with relative basal level.

Fig. (4)

Pre and 4 hours post ischemic induction ECG trace of 1 animal from the LO+ISO group that shows ST segment elevation in VI and aVR leads and ST segment depression in V2→V6 leads 4h after ischemia induction.

Fig. (5)

H & E stained sections of heart tissue. (A) CTL group heart section showing normal appearance of myocardial fibers. (B) Degeneration of myocardial fibers and leucocyte infiltration in a heart of ISO group. (C) Congestion of cardiac tissue in a heart of SO group. (D) Hypereosinophilic bundles and leucocyte infiltration in a heart of SO +ISO group. (E) Congestion and hemorrhage of cardiac tissue in a heart of LO group. (F) Hypereosinophilic bundles, leucocyte infiltration, congestion and hemorrhage of cardiac tissue in a heart of LO +ISO group. White arrow: congestion and hemorrhage, triangle: leucocyte infiltration, black arrow with empty tail: Hypereosinophilic bundles, black arrow with dotted tail: Necrosis. The magnification of A and C is × 400 and others are × 100.