Fujiko Sanae

Long term effects of phlebotomy on biochemical and histological parameters of chronic hepatitis C

OBJECTIVE:There is considerable evidence that iron is a risk factor for liver injury in chronic hepatitis C. Known as iron reduction therapy, phlebotomy reduces serum ALT activity. This effect might continue with maintenance phlebotomy and result in slower progression of liver fibrosis.METHODS:We examined the biochemical parameters and liver histology of patients with chronic hepatitis C treated by maintenance phlebotomy. For biochemical evaluation, 25 patients were treated by initial phlebotomy to reduce serum ferritin levels to 10 ng/ml or less and then observed for 5 yr with maintenance phlebotomy to maintain the iron-deficient state. For histological evaluation, liver biopsies were performed before and after the study period in 13 of the patients. Thirteen patients who were virological nonresponders to interferon alone and had undergone second liver biopsies after more than 3 yr served as histological controls.RESULTS:Serum aminotransferase levels were decreased significantly by initial phlebotomy and remained at the same levels during the study period (p < 0.05). The grading scores were improved significantly in the study group (p < 0.05) and unchanged in the controls. The staging scores remained unchanged in the study group but were increased in the controls (p < 0.005). Disease progression was significantly different between the two groups (p < 0.05).CONCLUSIONS:These results suggest that phlebotomy with maintenance lowers serum aminotransferase levels, improves liver inflammation, and suppresses the progression of liver fibrosis in chronic hepatitis C.

AVAQ 594-597 deletion of the TfR2 gene in a Japanese family with hemochromatosis

The majority of Caucasian patients with hemochromatosis are homozygous for C282Y mutation of the HFE gene. In contrast to its high prevalence in Caucasians, hemochromatosis is a rare disorder in Japan. This may be due to the low prevalence of the C282Y mutation of the HFE gene in Japanese. Recent reports suggest that the mutations of transferrin receptor 2 (TfR2) gene may be involved in non-HFE hemochromatosis. Therefore, we investigated the TfR2 gene of 6 sporadic and 5 familiar cases of Japanese hemochromatosis. Three siblings in one family were found to be homozygous for an AVAQ 594-597 deletion. All three had severe iron deposits in the hepatocytes and bile ducts, but none was affected by diabetes mellitus. This mutation was not detected in 100 control individuals. Further study was undertaken to investigate whether the large deletion of the TfR2 gene is the mutation responsible for some of the Japanese hemochromatosis cases.

Effects of catechins on vascular tone in rat thoracic aorta with endothelium.

The effects of eight catechin derivatives on vascular tone in rat thoracic aorta were examined. Catechin derivatives (10 microM) potentiated the contractile response to phenylephrine in endothelium-intact arteries. The potentiations produced by EGCg and EGC were almost absent in endothelium-denuded arteries and abolished by N(G)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis. The catechin derivatives also inhibited endothelium-dependent relaxation in response to acetylcholine. The order of catechin derivatives ranked in terms of both increasing vascular reactivity and impairing endothelium-dependent relaxation was similar; (-)-gallocatechin (GC) >or= (-)-epigallocatechin (EGC) >or= (-)-gallocatechin gallate (GCg) >or= (-)-epigallocatechin gallate (EGCg) >or= (-)-catechin (C) >or= (-)-epicatechin (EC) >or= (-)-catechin gallate (Cg) >or= (-)-epicatechin gallate (ECg). In addition, EGC inhibited the endothelium-independent relaxation evoked by both sodium nitroprusside and NOC-7, a spontanous NO releaser, but EGCg inhibited only that by NOC-7. These findings indicate that catechin derivatives produce a potentiation of the contractile response and an inhibition of the vasorelaxant response, probably through inactivation of endothelium-derived nitric oxide (NO), and that the hydroxyl on C-5 of the B ring together with the stereoscopic structure between the C-3 group and the B ring of flavanols was of importance in mediating the above effects and that the substitution of a gallate group of C-3 attenuated the effects, probably due to a decreased response to solube guanylate cyclase in vascular smooth muscle cells.

Mutational analysis of the MRP2 gene and long-term follow-up of Dubin-Johnson syndrome in Japan.

BackgroundRecent studies have indicated that dysfunction or loss of the multidrug resistance protein 2 (MRP2) is the molecular basis of Dubin-Johnson syndrome (DJS). To clarify the genetic basis of the disease and the long-term stability of serum bilirubin levels, we conducted a mutational analysis of the MRP2 gene and followed up serum bilirubin levels in Japanese DJS patients 30 years after they were originally diagnosed, based on traditional criteria.MethodsPatients were interviewed by telephone, and blood tests, including a genetic analysis of MRP2, were performed on the patients and family members who gave informed consent.ResultsOver the 30 years, hyperbilirubinemia remained unchanged in four of the five patients studied, while it worsened in 1 patient whose DJS was complicated by chronic hepatitis C. From an MRP2 gene mutational analysis, six mutations, including the novel mutation 1177C>T, were found. Three patients of a consanguineous family were homozygotes for three mutations (298C>T, 1967+2T>C, and 2439+2T>C). Two patients were compound heterozygotes (1177C>T/2302C>T and 1967+2T>C/2026G>C). A familial study showed no difference in serum bilirubin levels between mutant/wild heterozygotes and wild/wild homozygotes.ConclusionsThe hyperbilirubinemia of four Japanese patients with DJS, one of whom had a novel mutation, 1177C>T, of the MRP2 gene, had not worsened with aging.

Cyclic nucleotide phosphodiesterase isoenzymes in guinea-pig tracheal muscle and bronchorelaxation by alkylxanthines

In this study the phosphodiesterase (PDE) isoenzymes in guinea-pig trachealis smooth muscle were separated by DEAE-Sepharose anion exchange chromatography, identified, and characterized. Furthermore the effect of theophylline and 1-n-butyl-3-n-propylxanthine (BPX) on the isolated PDE isoenzymes and on their tracheal relaxant effect were investigated and compared with the nonxanthine PDE inhibitors amrinone and Ro 20-1724. We identified five distinct isoenzymes in guinea-pig tracheal muscle; calcium/calmodulin-stimulated cyclic AMP PDE (PDE I), cyclic GMP-stimulated cyclic AMP PDE (PDE II), cyclic GMP-inhibited and amrinone-sensitive cyclic AMP PDE (PDE III), cyclic AMP-specific and Ro 20-1724-sensitive PDE (PDE IV), and cyclic GMP-specific PDE (PDE V). BPX strongly inhibited the PDE IV isoenzyme with high selectivity, while the inhibitory effect of theophylline was weak. The PDE IV inhibitors BPX and Ro 20-1724 synergistically increased the relaxant effect of the beta 2-adrenoceptor agonist salbutamol in carbachol-contracted trachea much more strongly than theophylline. In contrast, amrinone, a PDE III inhibitor, hardly influenced the relaxant effect of salbutamol, suggesting that the PDE IV isoenzyme is functionally associated with beta 2-adrenoceptors in guinea-pig trachea and that inhibition of this enzyme potentiates the ability of salbutamol to increase the intracellular cyclic AMP content. These results indicate that the PDE IV isoenzyme plays a significant role in alkylxanthine-mediated relaxation of guinea-pig trachea.

Selective Bronchodilators from 1‐(5′‐Oxohexyl)xanthines

Abstract— A series of twenty one 1‐(5′‐oxohexyl)xanthines substituted with alkyl chains at the N 3 and N 7 positions of the xanthine nucleus were prepared and their relaxant activity in guinea‐pig isolated tracheal muscle and positive chronotropic activity in isolated right atrium of guinea‐pig were compared. The tracheal relaxant activities were markedly increased with alkyl chain length at the N 3 position, but decreased by the N 7 alkylation. The positive chronotropic activities in the right atrium were increased by introduction of an n‐propyl group at the N 3 position but decreased by substitution of longer alkyl chains, and the action on the heart was diminished by N 7 substitution. The activities of compounds on cAMP‐phosphodiesterase (PDE) and binding of [3H]8‐cyclopentyl‐1,3‐dipropylxanthine were measured in the homogenate of tracheal muscle and the membrane preparation of cerebral cortex, respectively. No relationship among tracheal muscle relaxant activity, cAMP‐PDE inhibitory activity and adenosine antagonism of these xanthines was observed, and other action mechanisms should be considered for their relaxant activities. This study indicated that N 3 alkylation is important for the selectivity for tracheal muscle, while the introduction of long alkyl chains such as n‐butyl and n‐pentyl groups at the N 3 and N 7 positions diminished the potency for the right atrium in guinea‐pigs. 3‐n‐Pentyl‐ and 7‐methy]‐3‐n‐pentyl‐1‐(5′‐oxohexyl)xanthines showed much higher bronchoselectivity than oxpentifylline and theophylline.

A comparison of adrenergic receptors of rat ascites hepatoma AH130 cells with those of normal rat hepatocytes

The pharmacological specificity of adrenergic receptors in the plasma membrane of rat ascites hepatoma AH130 cells was compared with that in normal rat hepatocytes. The number of [125I]iodocyanopindolol-binding sites was much greater in AH130 cells than in the hepatocytes. We characterized the alpha-adrenergic receptor subtypes using the alpha 1-selective ligand [3H]prazosin and the alpha 2-selective ligand [3H]clonidine. AH130 cells had fewer prazosin-binding sites than the hepatocytes and about 8 times as many clonidine-binding sites of high affinity. The results showed that the adrenergic receptors in AH130 cells have pharmacological properties that are very different from those of the receptors in normal rat hepatocytes.

Hypoglycaemic effects of Shokatsu-Cha (Xiao-Ke-Ca) in streptozotocin-induced diabetes mellitus

Shokatsu‐cha is a novel formula for diabetic mellitus based on the traditional Chinese medicine and composed of Dioscoreae rhizoma, Adenophorae radix, Rehmanniae radix, Anemarrhenae rhizoma, Platycodi radix, Salviae miltiorrhizae radix, Epimedii folium and Lycii fructus. The hypoglycaemic effect of Shokatsu‐cha was evaluated in streptozotocin (STZ)‐induced diabetic mice and rats. When orally administered once a day for 10 days to the mice intraperitoneally injected with STZ, the Shokatsu‐cha extract suppressed the increase of the blood glucose level during administration. In the in situ intestine circulation method, the Shokatsu‐cha extract and its ethanol‐eluted fraction inhibited the glucose absorption in STZ‐induced diabetic rats. The ethanol‐eluted fraction also inhibited the increase of blood glucose level in an oral glucose tolerance test using diabetic mice. This study indicates that a part of the hypoglycaemic effect of Shokatsu‐cha is based on its inhibitory action on intestinal glucose absorption in diabetes.

Reverse relationship between malignancy and cyclic AMP-dependent protein kinase activity in Yoshida rat ascites hepatomas

Rat ascites hepatoma (AH) cells (10(6) cells/head) inoculated intraperitoneally into rats had host-killing ability (malignancy) in the order AH66F > AH44 > AH13 > AH7974 > AH109A > AH66 > AH130. The life span of the rats after inoculation closely correlated with the activity of cyclic AMP-dependent protein kinase (protein kinase A) in the tumor cells but not the activity of Ca2+/phospholipid-dependent protein kinase (protein kinase C). N-[2-[N-[3-(4-chlorophenyl)-1-methyl-2-propenyl]amino]ethyl]-5- isoquinoline-sulfonamide (H-87), a potent, selective inhibitor of protein kinase A, inhibited in vitro growth of these hepatoma cells with a similar potency and, intraperitoneally injected, prolonged the lives of rats bearing less malignant AH66 cells (with high protein kinase A activity) but did not affect the life span of rats bearing highly malignant AH66F cells (with low protein kinase A activity). On the other hand N-(2-methylpiperazyl)-5-isoquinolinesulfonamide (H-7), an inhibitor of protein kinase C, inhibited AH66F cells more than AH66 cells, but did not influence the life span of rats bearing either hepatoma. From these results it is deduced that protein kinase A may be important in the regulation of malignancy and in vivo proliferation of AH cells.