title: Endogenous content and release of [(3)H]-GABA and [(3)H]-glutamate in the spinal cord of chronically undernourished rat.
abstract: The aim of this study was to determine the effect of chronic undernutrition on the content and release of γ-amino butyric acid (GABA) and glutamate (GLU) transmitters in the rat spinal cord. The release of [(3)H]-GABA and [(3)H]-GLU was determined by radioactive liquid scintillation techniques, and the concentrations of GABA and GLU in spinal cord preparations from control and undernourished young rats (50-60 days old) were measured by reverse-phase HPLC. The GABA and GLU contents in the lumbar spinal dorsal horn (L6 segment) were significantly lower in undernourished rats relative to control rats (22.2 ± 3.7 and 10.7 ± 1.9 %, respectively; P < 0.05). Spinal cord blocks from undernourished animals also showed lower rates of [(3)H]-GABA and [(3)H]-GLU release than controls (27.6 ± 3.5 and 12.8 ± 2.5 %, respectively; P < 0.01). We propose that the decreases in GLU content and release are consistent with a reduced activation of either afferent fibers, spinal glutaminergic neurons, or both. Furthermore, we propose that the decreased content and release of GABA in undernourished animals are related to a depression in pre- and post-synaptic inhibition. In addition, we hypothesize that the reductions in GABA content and release serve as compensatory mechanisms to counterbalance decreases in sensory transmission and GLU content in the spinal cord of the chronically undernourished rat.
authors.affiliation: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y Estudios Avanzados del IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, AP. 14-740, Mexico, DF 07000, Mexico.
authors.forename: Salvador
authors.initials: S
authors.lastname: Quiróz-González
authors.forename: Rodrigo Erick
authors.initials: RE
authors.lastname: Escartín-Pérez
authors.forename: Francisco
authors.initials: F
authors.lastname: Paz-Bermudez
authors.forename: Bertha
authors.initials: B
authors.lastname: Segura-Alegría
authors.forename: Celia
authors.initials: C
authors.lastname: Reyes-Legorreta
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Guadarrama-Olmos
authors.forename: Benjamin
authors.initials: B
authors.lastname: Florán-Garduño
authors.forename: Ismael
authors.initials: I
authors.lastname: Jiménez-Estrada
mesh_terms: D000818:Animals; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002118:Calcium / Q000502:physiology; D003627:Data Interpretation, Statistical; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D044342:Malnutrition / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D013268:Stimulation, Chemical; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018377:Neurotransmitter Agents; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D011188:Potassium; D002118:Calcium