Regulation of glutamate level in rat brain through activation of glutamate dehydrogenase by Corydalis ternata

When treated with protopine and alkalized extracts of the tuber of Corydalis ternata for one year, significant decrease in glutamate level and increase in glutamate dehydrogenase (GDH) activity was observed in rat brains. The expression of GDH between the two groups remained unchanged as determined by Western and Northern blot analysis, suggesting a post-translational regulation of GDH activity in alkalized extracts treated rat brains. The stimulatory effects of alkalized extracts and protopine on the GDH activity was further examined in vitro with two types of human GDH isozymes, hGDH1 (house-keeping GDH) and hGDH2 (nerve-specific GDH). Alkalized extracts and protopine activated the human GDH isozymes up to 4.8-fold. hGDH2 (nervespecific GDH) was more sensitively affected by 1 mM ADP than hGDH1 (house-keeping GDH) on the activation by alkalized extracts. Studies with cassette mutagenesis at ADP-binding site showed that hGDH2 was more sensitively regulated by ADP than hGDH1 on the activation by Corydalis ternata. Our results suggest that prolonged exposure to Corydalis ternata may be one of the ways to regulate glutamate concentration in brain through the activation of GDH.

Characteristics of Shigella sonnei Isolated in Kyungsangbuk-do in 1998: Biochemical Characteristics, Biotyping, Antibiotic Resistance Pattern, and Plasmid Profile / 한국역학회지

Thirty nine strains and 109 strains of Shigella sonnei were isolated from the outbreaks of Youngchun and Kyungju, respectively, while 15 strains were isolated from sporadic cases of eight regions in Kyungbuk province from September to November in 1998. We investigated the relationship among the S. sonnei strains by using biochemical characteristics, biotyping, antibiotic resistance pattern, and plasmid profile. Among the isolates, seven strains of S. sonnei isolated in Youngchun showed gelatin hydrolyase positive but the others showed gelatin hydrolyase negative. One hundred and fifty two strains were a type, while eleven among thirty nine strains isolated in Youngchun were g type. Antibiotics resistance patterns of S. sonnei strains isolated in Youngchun and Kyungju were significantly different. Thirty nine strains of S. sonnei isolated in Youngchun were resistant to SM, TE, and TMP/SMX, while eighty six of S. sonnei among one hundred and nine strains isolated in Kyungju were resistant to AM, CB, K, SM, TE, and TMP/SMX. Antibiotics resistance patterns of residual twenty three isolates were similar to those of eighty six strains. The Plasmid profiles of strains of S. sonnei isolated from the Kyungju were different from those of S. sonnei strains isolated in Youngchun. The Plasmid profiles of S. sonnei strains isolated from Youngchun were identical to those of a S. sonnei strains randomly selected from the outbreak in Daegu in 1998. The Plasmid profiles of S. sonnei strains isolated from Kyungju were identical to those of two strains of S. sonnei randomly selected from the outbreaks of Kanglung and Wonju in 1998. From the above results, it is considered that the strains of S. sonnei isolated from Kyungju and Youngchun region are not identical clone.