OBJECTIVETo investigate the effects and the mechanisms of the first-generation histamine H(1)-antagonist diphenhydramine and the second-generation histamine H(1)- antagonist fexofenadine on seizure development of pentylenetetrazole (PTZ)-induced kindling in rats.

METHODSThe first-or second-generation histamine H(1)-antagonists and/or histidine were ip injected in rats every 48 h, followed by a subconvulsive dose of PTZ (35 mg/kg). Then the behavioral changes were observed for 30 min after every injection of PTZ. The histamine content of brain was measured spectrofluorometrically.

RESULTCompared with the control group, diphenhydramine (5 mg/kg) significantly augmented the severity of seizure development of PTZ-induced kindling, whereas fexofenadine (5 mg/kg) had no marked influence. The effects of diphenhydramine were antagonized by histidine, the precursor of histamine.

CONCLUSIONSeizure development of PTZ-induced kindling is promoted by the first-but not the second generation histamine H(1)-antagonists via the blockade of brain histamine H(1)-receptor.

Animals ; Histamine ; physiology ; Histamine H1 Antagonists ; pharmacology ; Histamine H1 Antagonists, Non-Sedating ; pharmacology ; Histidine ; pharmacology ; Kindling, Neurologic ; drug effects ; Male ; Pentylenetetrazole ; Rats ; Rats, Sprague-Dawley ; Seizures ; chemically induced

OBJECTIVETo investigate the effect of alahistidine on brain histamine content and seizure development.

METHODSThe kindling seizure was induced by ip injection with subconvulsant dose of pentylenetetrazole every 48 h. Monoamines and their metabolites were measured using a HPLC system and fluorometric assay.

RESULTChronic low histamine feeding markedly decreased histamine content in cortex and hypothalamus, and promoted seizure development induced by pentylenetetrazole. However, alahistidine feed reversed the decreased histamine content and slowed seizure development caused by low histamine feed. Both low histamine and alahistidine feed had no effect on norepinephrine, dopamine and its metabolites.

CONCLUSIONAlahistidine may affect histaminergic system and seizure development.

Animals ; Brain Chemistry ; drug effects ; Carnosine ; analogs & derivatives ; pharmacology ; Histamine ; analysis ; Male ; Pentylenetetrazole ; Rats ; Rats, Sprague-Dawley ; Receptors, Histamine H1 ; physiology ; Seizures ; chemically induced

We verified the educational outcomes and effects of the practice of Problem-based learning (PBL) on the theme of Kampo medicine and the continuous academic support. From 2013 to 2021, we conducted Kampo PBL for second-year medical students, and compared the results of Kampo exams in the fourth year between Kampo PBL participants and non-participants. Moreover, the learning obtained through subsequent academic activities was extracted from their free-form text. Kampo PBL was performed for a total of 26 groups. Participants who underwent Kampo PBL (n = 72) scored significantly higher than those who did not (n = 734) (p<0.05). In addition, academic support resulted in 5 academic presentations in an academic conference and 3 articles published in academic journals. The lessons learned included “concretization of understanding of Kampo medicine,” “valuable experience in academic activities,” and “promoting motivation and its impact on the future.” Kampo PBL improved knowledge about Kampo medicine, and academic activities cultivated the research mind.