title: Disturbance of serotonergic neurotransmission in patients with postmyocardial infarction and depression.
abstract: The objective of this study was to assess the hypothesis that patients who develop depression after myocardial infarction (MI) have a lower level of brain serotonergic neurotransmission through measurement of plasma free fraction of L-tryptophan and intensity-dependence auditory-evoked potentials (IDAEPs). A cross-sectional study was carried out in 74 adults after MI. Thirty-four patients suffered from depression and 40 patients did not demonstrate depressive symptoms. We measured the free fraction, bound and total plasma L-tryptophan, and neutral amino acids as well as recording IDAEPs. Patients who developed depression after MI showed a significantly lower level in the free fraction of L-tryptophan and in the ratios of free fraction of L-tryptophan/total L-tryptophan and free fraction of L-tryptophan/neutral amino acids. It is noteworthy that the slope of the amplitude/stimulus intensity functions (ASF slope) of the N1/P2 component was significantly higher post-MI in depressed patients. Higher ASF slope of the N1/P2 component associated with a low free fraction of L-tryptophan in plasma reflect a low brain serotonergic neurotransmission. These findings suggest an important deterioration of brain serotonergic activity as a pathophysiological mechanism in post-MI patients for the development of clinical depression. Therefore, we propose these biochemical and electrophysiological procedures as noninvasive clinical indicators of brain serotonergic activity in these patients.
authors.affiliation: Laboratorio de Patología Molecular, Unidad de Investigación Biomolecular, Hospital de Cardiología, Centro Médico Nacional Siglo XXI (CMN-SXXI), Instituto Mexicano del Seguro Social (IMSS), Av. Cuauhtémoc 330, México, DF, México. gmanjarrezg@gmail.com
authors.forename: Gabriel
authors.initials: G
authors.lastname: Manjarrez-Gutiérrez
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Ramírez-Campillo
authors.forename: Gabriela
authors.initials: G
authors.lastname: Borrayo-Sánchez
authors.forename: Jorge
authors.initials: J
authors.lastname: Hernández-Rodríguez
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003863:Depression / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D009435:Synaptic Transmission; D014364:Tryptophan / Q000097:blood
chemical_list: D012701:Serotonin; D014364:Tryptophan