Influence of SKF81297 on Catecholamine Release from the Perfused Rat Adrenal Medulla

The aim of the present study was to investigate the effects of 6-chloro-7,8-dihydroxy-1-phenyl-2,3, 4,5-tetrahydro-1H-3-benzazepine (SKF81297), a selective agonist of dopaminergic D1 receptor, on the secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused rat adrenal gland, and also to elucidate the mechanism involved. SKF81297 (10~100microM) perfused into an adrenal vein for 60 min produced dose- and time-dependent inhibition of CA secretory responses evoked by ACh (5.32 mM), high K+ (56 mM), DMPP (100microM) and McN-A-343 (100microM). Also, in adrenal glands loaded with SKF81297 (30microM), the CA secretory responses evoked by Bay-K-8644 (10microM), an activator of L-type Ca2+ channels and cyclopiazonic acid (10microM), an inhibitor of cytoplasmic Ca2+-ATPase were also inhibited. However, in the presence of the dopamine D1 receptor antagonist, (R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-benzazepine-7-ol (SCH23390, 3microM), which is a selective antagonist of dopaminergic D1 receptor, the inhibitory responses of SKF81297 (30microM) on the CA secretion evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644, and cyclopiazonic acid were significantly reduced. Collectively, these experimental results suggest that SKF81297 inhibits the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) and membrane depolarization. This inhibitory of SKF81297 seems to be mediated by stimulation of dopaminergic D1 receptors located on the rat adrenomedullary chromaffin cells, which are relevant to extra- and intracellular calcium mobilization. Therefore, it is thought that the presence of the dopaminergic D1 receptors may be involved in regulation of CA release in the rat adrenal medulla.

Myeloperoxidase (MPO) Isozymes of Normal Neutrophils from Normal Persons and Reactive Neutrophils from Patients with Neutrophilia; Using 10% Native PAGE and Activity Stain for MPO / 대한혈액학회지

BACKGROUND: MPO is an antimicrobial enzyme in the primary granule of neutrophil. MPO exhibits MPO-I, MPO-II, MPO-III using chromatography in human peripheral leukocytes. we investigated MPO isozymes from human leukocytes of peripheral blood. METHODS: Neutrophils were prepared from 5-8mL of peripheral blood in the group of normal persons (normal group) and the group of patients with neutrophilia (patient group). Their cells were adjusted to 2.4X10(7) cells and sonified. We got finally the crude MPO from which native PAGE was performed and treated with diaminobenzine and H2O2. RESULTS: Normal neutrophil MPO had MPO-1 and MPO-2. The expression rates of MPO-1 and that of MPO-2 were respectively 100%, 67.5% in the normal group and 56.6%, 30.2% in the patient group (P=0.000, P=0.000). The expression rate of combined MPO-1 and MPO-2 and that of MPO-1 without MPO-2 were respectively 67.6%, 32.4% in the normal group and 28.3%, 28.3% in the patient group (P=0.000, P=0.000). The expression of MPO-2 without MPO-1 and that of no MPO isozymes were respectively 0.0%, 0.0% in the normal group and 1.9%, 41.5% in the patient group (P=0.000, P=0.000). CONCLUSION: Normal neutrophil MPO expresses MPO-1 and MPO-2 usig native PAGE. The main MPO isozyme is MPO-1. Expressions of MPO isozymes are variable in the patient group.

Effect of Leaf-Extract from Camellia sinensis and Seed-Extract from Casia tora on Viability of Mutans Streptococci isolated from the interface between orthodontic brackets and tooth surfaces / 대한치과교정학회지

Mutans streptococci is the major causative factor in dental caries. Especially, orthodontic patients with fixed appliance are a risk group for dental caries. Because fixed appliances attached on teeth may change the environment of dental plaque, the enamel decalcification or dental caries around the bracket and band is a major side effect of orthodontic treatment. The aim of this study was to search plant extracts that have antimicrobial effect on mutans streptococci. Seed-extract of Casia tora were prepared with ethanol and CHMC-2032, the leaf-extracts from Camellia sinensis extract, was obtained extract, 2 type strains and 20 clinical isolates of mutans streptococci isolated from the interface between orthodontic brackets and tooth surfaces in the orthodontic patients were used in this study. The minimal inhibitory concentration of CHMC-2032 was 5 mg/ml on the S. mutans KCTC 3065, S. sobrinus KCTC 3088, and 8 clinical isolates of S. sobrinus. However, there was no antibacterial effect of seed-extract of C. tora on mutans streptococci. These data suggest that green tea may be more effective than the tea prepared from C. tora in the prevention of enamel decalcification or dental caries around brackets.