Influence of low dietary histamine on the seizure development of chemical kindling induced by pentylenetetrazol in rats
Abstract
Aim: To determine the role of dietary low histamine on the seizure development of
pentylenetetrazol (PTZ)-induced kindling in rats. Methods: After 14 d of feeding
on a low histamine diet (LH, containing 0.145 μmol/g of histamine), the rats were
chemically kindled by repeated intraperitoneal injection of a subconvulsant dose
of PTZ (35 mg/kg) once every 48 h, and seizure activity of kindling was recorded
for 30 min. Histamine in brain samples was analyzed using a high performance
liquid chromatography system with a fluorescence spectrofluorometer. Results: The LH diet induced an increase in seizure response (seizure susceptibility) to the
first trial of PTZ, and resulted in facilitation of subsequent PTZ kindling process
(seizure development). The histamine levels in the cortex, hippocampus, and
hypothalamus of LH-treated rats decreased significantly and these changes correlated
well with seizure behavior (r = 0.875, 0.651, and 0.796, respectively). In addition,
chronic kindled seizures resulted in a significant increase of the histamine content
in the cortex and hypothalamus in the LH-fed groups. Conclusion: These findings
indicate that the histamine in daily food could influence the brain histaminergic
function, and play an important role in regulating seizure susceptibility.
Keywords:
pentylenetetrazol (PTZ)-induced kindling in rats. Methods: After 14 d of feeding
on a low histamine diet (LH, containing 0.145 μmol/g of histamine), the rats were
chemically kindled by repeated intraperitoneal injection of a subconvulsant dose
of PTZ (35 mg/kg) once every 48 h, and seizure activity of kindling was recorded
for 30 min. Histamine in brain samples was analyzed using a high performance
liquid chromatography system with a fluorescence spectrofluorometer. Results: The LH diet induced an increase in seizure response (seizure susceptibility) to the
first trial of PTZ, and resulted in facilitation of subsequent PTZ kindling process
(seizure development). The histamine levels in the cortex, hippocampus, and
hypothalamus of LH-treated rats decreased significantly and these changes correlated
well with seizure behavior (r = 0.875, 0.651, and 0.796, respectively). In addition,
chronic kindled seizures resulted in a significant increase of the histamine content
in the cortex and hypothalamus in the LH-fed groups. Conclusion: These findings
indicate that the histamine in daily food could influence the brain histaminergic
function, and play an important role in regulating seizure susceptibility.