BACKGROUND: We set out to detect whether morphine is present in tissue taken from a patient with intractable temporal lobe epilepsy and to characterize the presence and nature of mu opiate receptor subtypes in this tissue. CASE REPORT: In temporal lobe tissue, resected during anteromedial temporal lobectomy for intractable focal epilepsy, morphine was identified by quantitative radioimmunoassay (RIA) coupled to electrochemical detection via high-pressure liquid chromatography (HPLC). In addition, RNA isolated from the medial and lateral temporal lobe specimens was analyzed by conventional and real time reverse transcriptase-polymerase chain reaction (RT-PCR) for the expression of different human receptor gene transcripts. RIA revealed the presence of morphine at 3.4 nanograms per gram of tissue wet weight. Using RT-PCR and a primer specifically set for the mu3 (550 base pair fragment) and mu4 (880 base pair fragment) MOR splice variants, a mu4 splice variant was identified in both brain sections. CONCLUSIONS: This human brain tissue study of a subject with temporal lobe epilepsy documents the presence of endogenous morphine and of a mu4 splice variant. These findings may have implications for our understanding of the mechanism of temporal lobe epilepsy.
BACKGROUND: We set out to detect whether morphine is present in tissue taken from a patient with intractable temporal lobe epilepsy and to characterize the presence and nature of mu opiate receptor subtypes in this tissue. CASE REPORT: In temporal lobe tissue, resected during anteromedial temporal lobectomy for intractable focal epilepsy, morphine was identified by quantitative radioimmunoassay (RIA) coupled to electrochemical detection via high-pressure liquid chromatography (HPLC). In addition, RNA isolated from the medial and lateral temporal lobe specimens was analyzed by conventional and real time reverse transcriptase-polymerase chain reaction (RT-PCR) for the expression of different human receptor gene transcripts. RIA revealed the presence of morphine at 3.4 nanograms per gram of tissue wet weight. Using RT-PCR and a primer specifically set for the mu3 (550 base pair fragment) and mu4 (880 base pair fragment) MOR splice variants, a mu4 splice variant was identified in both brain sections. CONCLUSIONS: This human brain tissue study of a subject with temporal lobe epilepsy documents the presence of endogenous morphine and of a mu4 splice variant. These findings may have implications for our understanding of the mechanism of temporal lobe epilepsy.
Authors: George B Stefano; Kirk J Mantione; Lismary Capellan; Federico M Casares; Sean Challenger; Rohina Ramin; Joshua M Samuel; Christopher Snyder; Richard M Kream Journal: J Bioenerg Biomembr Date: 2015-09-09 Impact factor: 2.945