Effect of epidermal growth factor on adrenaline induced effects in isolated rabbit heart

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