Wistar strain rats as the model for IgE antibody experiments

The amount of plasma IgE antibody formed and its change over time were investigated by enzyme-linked immunosorbent assay (ELISA) in male and female Sprague-Dawley (SD), Donryu, and Wistar strain rats. IgE antibody formation was initiated by injecting a mixture of 2,4-dinitrophenylated ascaris extract (DNP-As) as antigen and killed Bordetella pertussis as adjuvant into the paws of the animals. The amount of IgE antibody formed was low on day 10 in both male and female SD (40-80 ng/ml) and Donryu (20-40 ng/ml) strain rats, and an increase in the amount was observed on day 20. The peak value of IgE antibody was observed day 10 in Wistar strain rats and was 130 and 200 ng/ml in the male and female rats, respectively. These results suggest that Wistar strain rats produce the most IgE antibody when DNP-As is used as antigen and they can serve as a model for allergic diseases.     

The effects of kampo-formulation and the constituting crude drugs, prescribed for the treatment of peptic ulcer on H,K-ATPase activity

We studied the effects of 17 kinds of Kampo-formulations prescribed for the treatment of peptic ulcer on H,K-ATPase activity. The activity was strongly inhibited by San-o-shashin-to ([symbol: see text], IC50 = 82 micrograms/ml), Bukuryo-in ([symbol: see text], IC50 = 110 micrograms/ml), Shakuyaku-kanzo-to ([symbol: see text], IC50 = 170 micrograms/ml), Hange-koboku-to ([symbol: see text], IC50 = 290 micrograms/ml), Dai-saiko-to ([symbol: see text], IC50 = 340 micrograms/ml), Irei-san ([symbol: see text], IC50 = 380 micrograms/ml) than other Kampo-formulations. Among the 17 kinds of crude drugs contained in these Kampo-formulation, Rhei Rhizoma, Coptidis Rhizoma, Glycyrrhiza Radix, Cinnamomi Cortex, and Poria have notable inhibitory effects (IC50 = 19-57 micrograms/ml). H,K-ATPase activity was inhibited by sennoside A (Rhei Rhizoma), sennoside B (Rhei Rhizoma), ergosterol (Poria), coptisine (Coptidis Rhizoma), glycyrrhizin (Glycyrrhiza Radix), glycyrrhetic acid (Glycyrrhiza Radix), gallic acid (Cinnamomi Cortex) in the 21 components of these crude drugs (IC50 = 1.6-7.9 x 10(-4) M). The inhibition of San-o-shashin-to and Bukuryo-in is considered to be mainly attributed to Rhei Rhizoma and Poria, respectively. The anti-gastric ulcer effects of San-o-shashin-to and Bukuryo-in may be ascribed to the inhibition of H,K-ATPase activity.     

Central serotonergic mechanisms on head twitch response induced by benzodiazepine receptor agonists

Intraperitoneal injection of benzodiazepine receptor agonists (estazolam, zopiclone, triazolam: 0.03-0.24 mmol/kg) induces the head twitch response (HTR). The present study was undertaken to examine the possible participation of the serotonergic system in the mechanism of head twitches induced by benzodiazepine receptor agonists (BZ-RAs). The HTR induced by BZ-RAs was suppressed by pretreatment with ketanserine (1 mg/kg, i.p.), a selective 5-HT(2) receptor antagonist. Pretreatment with fluoxetine (10 mg/kg, i.p.), a 5-HT reuptake inhibitor, and 8-hydroxy-2-(di-n-propylamino)tetralin, a 5-HT(1A) receptor agonist, also suppressed the HTR induced by BZ-RAs. These results suggest that the HTR induced by BZ-RAs may be the result of an activation of postsynaptic 5-HT(2) receptors, probably due to direct action.     

Diverse biological activities of moxa extract and smoke

Diverse biological activities of moxa extracts and smoke (gas phase) were investigated. Moxa was extracted with hot water (Fr. I), or ethanol (Fr. II), or extracted with hot water after ethanol wash (Fr. III) and then lyophilized to obtain the dried powders. Moxa smoke (containing a lot of gaseous components obtained by burning Moxa) (Fr. IV) was collected into phosphate-buffered saline and quantified spectrophotometrically. These extracts and Moxa smoke showed comparable cytotoxic activity against human oral tumor cell lines (HSC-2, HSG). Human gingival fibroblasts (HGF) were more resistant to any Moxa fractions. Neither of the extracts showed anti-HIV activity. Pretreatment of mice with Fr. I significantly reduced the lethal effect of E. coli infection. All extracts produced radicals under alkaline condition, with a maximum intensity at pH 10.5, and enhanced the radical intensity of sodium ascorbate. It was unexpected that these extracts show significant O2- scavenging activities. These data suggest the medicinal efficacy of Moxa extracts and smoke.     

Antinociceptive effects of intracerebroventricularly administered P2 purinoceptor agonists in the rat

We examined the effects of adenosine 5'-triphosphate (ATP) and its analogues administered intracerebroventricularly on nociceptive thresholds in rats. Intracerebroventricular (i.c.v.) administration of ATP (10 and 100 nmol/rat), alpha,beta-methylene-ATP (1-30 nmol/rat) and 2', 3'-O-(4-benzoylbenzoyl)-ATP (1-30 nmol/rat) dose-dependently elevated the mechanical nociceptive threshold in the paw pressure test. These antinociceptive effects were rapid and short-lasting, peaking at 5 min and disappearing by 20 min after the administration. However, i.c.v. administration of beta,gamma-methylene-ATP (1-30 nmol/rat) and UTP (10 and 100 nmol/rat) had no significant effects on the mechanical nociceptive threshold. In other tests, i.c.v. administration of alpha,beta-methylene-ATP (10 and 30 nmol/rat) prolonged the thermal nociceptive latency in the hot plate test, but only a higher dose (30 nmol/rat) of alpha,beta-methylene-ATP prolonged the latency in the tail flick test. alpha,beta-Methylene-ATP produced no motor deficit in the inclined plane test. These results suggest that P2X purinoceptors play an inhibitory role in nociception at the supraspinal level.     

A comparative study of the fluoroquinolone antibacterial agents on the action potential duration in guinea pig ventricular myocardia

We examined the effects of ten fluoroquinolone antibacterial agents, levofloxacin, sitafloxacin, trovafloxacin, ciprofloxacin, gemifloxacin, tosufloxacin, gatifloxacin, grepafloxacin, moxifloxacin and sparfloxacin, on action potentials recorded from guinea pig ventricular myocardia. Sparfloxacin prolonged action potential duration (APD) by about 8% at 10 microM and 41% at 100 microM. Gatifloxacin, grepafloxacin and moxifloxacin also prolonged APD at 100 microM by about 13%, 24% and 25%, respectively. In contrast, levofloxacin, sitafloxacin, trovafloxacin, ciprofloxacin, gemifloxacin and tosufloxacin had little or no APD-prolonging effect at concentrations as high as 100 microM. These findings suggest that there are differences in potency to prolong QT interval among the fluoroquinolones.     

Effect of poly-L-arginine on the nasal absorption of FITC-dextran of different molecular weights and recombinant human granulocyte colony-stimulating factor (rhG-CSF) in rats

The effect of poly-L-arginine (poly-L-Arg) on the in vivo nasal absorption of FITC-dextrans with a mean molecular weight ranging from 4.3 to 167 kDa and recombinant human granulocyte colony-stimulating factor (rhG-CSF) in rats were studied. When FITC-dextrans were co-administered intranasally with 1.0 w/v% poly-L-Args of different molecular weight (MW, ca. 45.5 and 92 kDa, poly-L-Arg (50) and poly-L-Arg (100)), the bioavailability (F(infinity)) increased markedly compared with that after administration of FITC-dextran alone. However, the F(infinity) decreased exponentially with the increasing molecular weight of FITC-dextrans. There was no significant difference between the enhanced nasal absorption of FITC-dextrans achieved by the co-administration of poly-L-Arg (50) and poly-L-Arg (100). Moreover, the relationship between the F(infinity) and the molecular weight of FITC-dextrans indicated that the molecular weight of protein drugs, which exhibited efficient absorption with poly-L-Arg, was about 20 kDa, when the lower limit of bioavailability for developing a potent transnasal delivery system was assumed to be about 10%. Indeed, the nasal absorption of rhG-CSF, which has a molecular weight of 18.8 kDa, was also increased after co-administration of 1.0 w/v% poly-L-Arg (50) and the F(infinity) was about 11%. It seems likely that poly-L-Arg can be used to provide adequate nasal absorption of various protein drugs which have a molecular weight of about 20 kDa, thereby allowing the successful development of a variety of transnasal drug delivery systems.     

Effect of hyperprolactinemia induced by pituitary grafts or castration on porphyrin content of the mouse Harderian gland

The histology and porphyrin concentrations of Harderian glands and plasma prolactin levels were examined in B6C3F1 mice castrated or isografted with pituitaries in combination with the administration of bromocriptine (2-bromo-á-ergocryptine), a potent suppressor of prolactin. Four pituitaries were transplanted underneath the bilateral kidney capsules of each mouse. Furthermore, we investigated Harderian porphyrins and plasma testosterone levels in mice that were castrated or treated with neuroleptic butyrophenone (timiperone), a potent accelerator of prolactin, and treated concurrently with bromocriptine. Light microscopically, pituitary grafts increased the concretion of porphyrin pigments within the Harderian gland lumina. Pituitary grafts or castration increased both Harderian porphyrin concentrations and plasma prolactin levels compared with the intact control mice. In pituitary-grafted or castrated mice, bromocriptine distinctly prevented the rise in both porphyrins and prolactin levels. Administration of butyrophenone did not result in any marked change in testosterone levels, although Harderian gland porphyrins were significantly increased. The present results indicate that in mice prolactin stimulates the porphyrin production of the Harderian gland and has an important role in the regulation of Harderian gland porphyrins.     

Potentiation of ibudilast inhibition of platelet aggregation in the presence of endothelial cells

Although communications between platelets and endothelial cells or other blood cells are important in in vivo thrombus formation, laboratory platelet function tests are usually performed in isolation from these surrounding cells. In this study, we evaluated the effect of an antiplatelet drug, ibudilast (3-isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine), on platelet aggregation in the presence and absence of human umbilical vein endothelial cells (HUVECs) and with the use of platelet-rich plasma (PRP) or whole blood as platelet samples. Stimulation-dependent platelet aggregation was weakened in the presence of HUVECs, which was especially prominent when the thrombin receptor-activating peptide SFLL (compared with ADP and epinephrine) was used as an aggregating agent. Ibudilast hardly affected SFLL-induced platelet aggregation (in PRP), while this antiplatelet agent was found to clearly inhibit this SFLL-induced response in a concentration-dependent manner, in the presence of HUVECs. Ibudilast tended to inhibit ADP- or epinephrine-induced platelet aggregation in the presence of HUVECs, but the effects were not statistically significant. Enhanced inhibition by ibudilast of SFLL-induced platelet aggregation (in the presence of HUVECs) was reproduced with the use of whole blood samples when a screen filtration pressure method was employed. It is suggested that the platelet aggregation studies in the presence of endothelial cells and/or other blood cells provide us with valuable information on platelet reactivity in vivo and improvement of antiplatelet therapy.