Suppression effects of carbonate on the interaction between stainless steel and phosphate groups of phosphate compounds in high-performance liquid chromatography and electrospray ionization mass spectrometry.

We examined the suppression methodology of the interaction between phosphate compounds, such as nucleotides, and the stainless steel surfaces of high-performance liquid chromatography and electrospray ionization mass spectrometry (HPLC/ESI-MS) equipment in an effort to prevent the tailing of peaks seen in HPLC chromatograms of phosphate compounds. Addition of carbonate (CO(3)(2-)) to mobile phase was highly effective in suppressing the interaction of phosphate compounds derived from a complexation between phosphate groups and metal ions that exist on a stainless steel surface in a mechanism similar to Fe(III)- and Cr(III)-immobilized metal affinity chromatography (IMAC). Addition of ammonium hydrogen carbonate to mobile phase achieved a simple and reliable HPLC/ESI-MS analysis of mono-, di-, and triphosphate compounds (six nucleotides) without peak tailing due to the interaction between stainless steel surfaces and phosphate groups.

Linkage map of Syrian hamster with restriction landmark genomic scanning.

We have constructed the linkage map with precise genetic analysis of the Syrian hamster, Mesocricetus auratus, according to the restriction landmark genomic scanning (RLGS) spot mapping method. Although only 3.2-6.

Biliary excretion of glycyrrhizin in rats: kinetic basis for multiplicity in bile canalicular transport of organic anions.

Purpose: To examine the presence of multiplicity for the biliary excretion of xenobiotic conjugates, we studied the disposition of glycyrrhizin (GR), which has glucuronide within its molecular structure and has the ability to inhibit the biliary excretion of liquiritigenin (LG) glucuronides.

Methods: GR was administered intravenously as a bolus to Sprague-Dawley (SD) rats which received an i.v.

A genetic linkage map of the Syrian hamster and localization of cardiomyopathy locus on chromosome 9qa2.1-b1 using RLGS spot-mapping.

The Syrian cardiomyopathic hamster (BIO14.6) has an inherited form of progressive myocardial necrosis and congestive heart failure. Although widely studied as an animal model for human hypertrophic cardiomyopathy, further genetic analysis has been limited by a scarcity of DNA markers.

A new mutant rat with hyperbilirubinuria (hyb).

We have discovered mutant rats with hyperbilirubinuria at the laboratories of Eisai Co., Ltd., Gifu, Japan, and established a new inbred mutant strain, which was designated Eisai Hyperbilirubinuria Rat (EHBR/Eis).

A new mutant rat with turning behavior (Tur).

A new rat mutant with abnormal behavior has been found in a closed colony of Slc: SD. The affected rats turned around after their own tails beginning 4-5 weeks after birth, in response to extroceptive stimuli, such as sound or vibration. The behavior was more pronounced in younger animals.

Biliary and renal excretions of cefpiramide in Eisai hyperbilirubinemic rats.

Eisai hyperbilirubinemic mutant rats (EHBRs) with conjugated hyperbilirubinemia were recently derived from Sprague-Dawley rats (SDRs). The pharmacokinetic characteristics of the beta-lactam antibiotic cefpiramide (CPM), which is mainly excreted into bile, were investigated in 10- and 20-week-old EHBRs and were compared with those in 20-week-old healthy SDRs. The pharmacokinetic parameters of CPM after an intravenous administration of 20 mg/kg of body weight were estimated for each rat by noncompartmental methods.

Multiple systems for the biliary excretion of organic anions in rats: liquiritigenin conjugates as model compounds.

Liquiritigenin (LG), 2, 3-dihydro-7-hydroxy-2-(4-hydroxyphenyl)-(S)-4H-1-benzopyran-4-1, is metabolized to five kinds of conjugates (glucuronides and sulfates) that are excreted predominantly into the bile (Shimamura et al., 1993). Using LG as a model compound, we studied the multiplicity for the biliary excretion of conjugates in vivo.

Alterations in the pharmacokinetics and protein binding of enprofylline in Eisai hyperbilirubinemic rats.

Mutant rats possessing conjugated hyperbilirubinemia have recently been established from Sprague-Dawley rats (SDRs) and are called Eisai hyperbilirubinemic rats (EHBRs). The effects of hyperbilirubinemia on the disposition, renal handling, and protein binding behavior of enprofylline, which is mainly excreted into the urine by an active tubular secretion mechanism, were investigated in 9- and 19-week-old EHBRs and compared with their age-matched normal SDRs. Enprofylline was administered intravenously at a dose of 2.

Influence of age on the disposition and renal handling of enprofylline in rats.

The effects of ageing on the pharmacokinetics, renal handling and protein binding of enprofylline were investigated in 6-, 13- and 18-month-old male Fischer 344 rats. Concentrations of enprofylline in plasma and urine were determined by HPLC, and pharmacokinetic parameters were estimated by model-independent methods. No significant differences in the volume of distribution, systemic clearance of enprofylline or urinary recovery of unchanged enprofylline (> 85%) were observed among any of the groups of rats.

[Establishment of hyperbilirubinuria rat mutant--a new animal model for jaundice].

A new animal model for jaundice, a hyperbilirubinemic rat mutant (EHBR, Eizai hyperbilirubinuria rat), was established from Sprague-Dawley rats. Hyperbilirubinemia was inherited as an autosomal recessive trait. The gene manifesting jaundice was named "hyb".

Kinetic analysis of hepatobiliary transport of organic anions in Eisai hyperbilirubinemic mutant rats.

The hepatobiliary transport of nonmetabolizable organic anions [cefodizime, dibromosulfophthalein, and indocyanine green (ICG)] was kinetically analyzed in Eisai hyperbilirubinemic rats (EHBR; Sprague-Dawley-derived mutant rats with conjugated hyperbilirubinemia). In EHBR, the biliary excretion of these anions was remarkably impaired, whereas the alteration in initial plasma disappearance was minimal. The kinetic analysis of the disposition of these ligands revealed 1) that the transport rate via bile canalicular membrane was severely impaired in EHBR for cefodizime and dibromosulfophthalein and 2) that the intracellular transport rate of ICG was decreased in EHBR, which contributed more than the decrease in the canalicular membrane transport to the net reduction of the excretion rate of ICG in EHBR.

Developmental aspects of a unique glutathione S-transferase subunit Yx in the liver cytosol from rats with hereditary hyperbilirubinuria. Comparison with rat fetal liver transferase subunit Yfetus.

The unique glutathione S-transferase (GST) subunit Yx, which is undetectable in normal adult rat liver cytosol, was shown to occur in the liver cytosol of rats with hereditary hyperbilirubinuria (EHB). The Yx subunit is a member of the Alpha-class GST subunits, and is immunologically closely related to the Yc subunit. The Yx subunit has an apparent M(r) of 26,400, different from those of Ya (M(r) 25,800), Yb1 and Yb2 (both M(r) 27,200) and Yc (M(r) 28,400).

A new rat mutant with chronic conjugated hyperbilirubinemia and renal glomerular lesions.

A new mutant strain of inbred Sprague Dawley rats with autosomal recessive hyperbilirubinuria, were studied by biochemical, histologic, and ultrastructural methods. The plasma bilirubin concentration in the homozygote was significantly higher than that of the heterozygote, and about 80% of the bilirubin was conjugated. Plasma BSP and ICG clearance were both severely delayed in the homozygote.

Biliary excretion of bile acid conjugates in a hyperbilirubinemic mutant Sprague-Dawley rat.

The hepatic transport of bile acid conjugates was studied in the Eisai hyperbilirubinuria rat, a Sprague-Dawley mutant rat with conjugated hyperbilirubinemia. Serum bile acid levels were increased, bile acid-independent bile flow was decreased and biliary glutathione concentrations were markedly decreased in the Eisai hyperbilirubinuria rat. Biliary excretion of sulfobromophthalein was markedly impaired and almost no glutathione conjugate was excreted in the bile of the Eisai hyperbilirubinuria rat.

Changes in serum and hepatic levels of immunoreactive prolyl hydroxylase in two models of hepatic fibrosis in rats.

Changes in serum and hepatic levels of immunoreactive prolyl hydroxylase (IRPH) as well as cellular localization of the enzyme were studied in 2 models of hepatic fibrosis, which was induced in male rats either by subcutaneous administration of CCl4 (Group A) or by intraperitoneal injection of porcine serum (Group B). Hepatic fibrosis appeared at the 8th week in Group A and at the 12th week in Group B, and liver cirrhosis developed at the 16th week in both models. Although tissue contents of hydroxyproline (HP) and IRPH increased in both models, only HP levels correlated with the degree of fibrosis.

Organic anion transport study in mutant rats with autosomal recessive conjugated hyperbilirubinemia.

The EHBR is a mutant rat strain with congenital conjugated hyperbilirubinemia bred from a Sprague-Dawley rat. Transport of conjugated bilirubin, indocyanine green, and tetrabromosulfophtalein from liver to bile is severely impaired in these rats. Serum bilirubin amounts to 6.

Inhibitory effect of acyclic retinoid (polyprenoic acid) on the secretion of alpha-fetoprotein in CCl4-treated rats.

A study was conducted to examine the inhibitory effect of acyclic retinoid (polyprenoic acid) on the secretion of alpha-fetoprotein (AFP) in rats with chronic liver damage induced by CCl4. Oral administration of the compound brought about a significant reduction of serum AFP levels at the time when liver cirrhosis was formed. Acyclic retinoid also decreased the activities of serum aminotransferases and ornithine carbamyl transferase, while it increased serum albumin levels, demonstrating the reduction of hepatic parenchymal damage.

Inhibitory effect of acyclic retinoid (polyprenoic acid) on hepatic fibrosis in CCl4-treated rats.

A study was conducted to examine the inhibitory effect of acyclic retinoid (polyprenoic acid) on the development of hepatic fibrosis induced by CCl4 in rats. Oral administration of the compound brought about a significant reduction in both serum and tissue levels of immunoreactive prolyl hydroxylase, a key enzyme of collagen formation. The result indicated that the rate of collagen synthesis in the liver was decreased which was consistent with histological findings.

Strain differences of rat liver carboxylesterase activities related to the phenotype difference of esterase-3 (egasyn).

It was demonstrated that the inbred strain EHBR had the C phenotype of esterase-3 judging from the absence of liver microsomal beta-glucuronidase and the pattern of esterase activities of liver homogenates after analytical isoelectric focusing. In addition, in the strain EHBR, liver microsomal hydrolase activities of acetanilide and isocarboxazid which are hydrolyzed well by esterase-3 were lower than in outbred Sprague-Dawley rat and inbred LEW rat having the D phenotype of esterase-3. These results suggest that the phenotype difference of esterase-3 is possible to cause the strain differences of liver microsomal carboxylesterase activities.

Morphological differentiation of human neuroblastoma cell lines by a new synthetic polyprenoic acid (E5166).

The prognosis of patients with advanced neuroblastoma remains poor despite recent progress in chemo/radiotherapy. Therapeutic trials on the induction of differentiation of neuroblastoma by chemical and biological agents have been attempted to improve patients' prognosis. Recently a new synthetic polyprenoic acid, E5166, having retinoic acid properties, has been described.