ABSTRACT
Acute psychological stressors induce damage in organs as heart. Catecholamines are responsible for acute stress effects. Adrenaline, through 1-adrenergic receptors; stimulates EOF release to the blood. Because plasma catecholamine concentration is high during the stress and afterwards, organs are exposed to combined effects of both catecholamines and EGF. Intermale fighting [IF stress model] does not raise plasma creatine kinase [CK] activity ,while increases plasma transaminase and lactate dehydrogenase [LDH] activities, So the heart is protected. EGF may protect the heart against the harmful effects of epinephrine. The present research studied EGF administration on adrenaline induced effects in the rabbit heart [invitro] of 8 groups of male white New Zealand rabbits. Heart tissues were excised and incubated. revealed a significant decrease in heart rate, contractility and coronary flow rate in Epidermal growth factor gp. A non significant change in heart rate and coronary flow rate and heart contractility after infusion of alpha blocker and adrenaline.While a significant decrease in heart rate, heart contractility and coronary flow rate in either adrenaline with beta Blocker group and or EGF with adrenaline and a blocker group. EGF with adrenaline and beta Blocker group produced a significant increase in heart rate, heart contractility and coronary flow rate. In spite of EGF positive effects on heart properties, it interfered with the adrenaline positive effects through Beta receptors