N-Methyl-D-aspartate-induced c-Fos expression is enhanced in the forebrain structures related to emotion in Fyn-deficient mice

Fyn tyrosine kinase is thought to be involved in the control of neuronal intracellular signal transduction elicited by neurotransmitter stimulation. Emotional disorders, such as fearfulness in Fyn-deficient mice, prompted us to investigate the neural mechanisms that lead to defective emotional expression by using functional neuroanatomical methods. In order to examine the reactivity of a specific neural network to excitatory neurotransmitter administration, we mapped the distribution of c-Fos-immunoreactive neurons after administering N-methyl-D-aspartate (NMDA) to control and mutant mice at the subthreshold dose for seizure induction. The induction of neuronal c-Fos-immunoreactivity by NMDA was enhanced in the Fyn-deficient mice, and there was a much greater increase in immunopositive neurons in certain well-defined areas, such as the amygdaloid medial nuclear subdivisions, hypothalamic paraventricular nucleus, and midbrain periaqueductal gray, of the mutant. NMDA-induced c-Fos expression was attenuated by pretreatment with D-(-)-2-amino-5-phosphonovaleric acid, a competitive NMDA antagonist, both in the control and the mutant mice. These findings suggest that the excitability of the projection system from the amygdala to the hypothalamus and midbrain, the main pathways of emotional expression, is enhanced in Fyn-deficient mice.

Spiral, herringbone, and triple-decker silver(I) complexes of benzopyrene derivatives assembled through eta(2)-coordination

Three novel silver(I) complexes with benzopyrene derivatives were synthesized and characterized in this paper. Treatment of AgClO(4)*H(2)O with 7-methylbenzo[a]pyrene (L(1)) afforded [Ag(2)(L(1))(toluene)(0.5)(ClO(4))(2)](n)() (1) which exhibits a 2-D sheet structure with double-stranded helical motifs. Reaction of AgCF(3)SO(3) with dibenzo[b,def ]chrysene (L(2)) gave rise to an unprecedented cocrystallization structure, ([Ag(2)(L(2))(CF(3)SO(3))(2)][Ag(2)(toluene)(2)(CF(3)SO(3))(2)])(n)() (2), formed by a 2-D neutral lamellar polymer and a 1-D neutral rodlike one. The ligand benzo[e]pyrene (L(3)) coordinated to silver(I) ions generating a closed triple-decker tetranuclear complex [Ag(4)(L(3))(4)(p-xylene)(ClO(4))(4)] (3) which can be regarded as a stacking polymer owing to existing intermolecular pi-pi stack interactions. The structural diversity of the silver(I) coordination polymers with polycyclic aromatic hydrocarbons is not only related to the stacking patterns of free polycyclic aromatic hydrocarbons in the crystalline state, but also the geometric shapes of the molecules for these free ligands. In addition, the coordination of solvents to metal ions plays a crucial role in the formation of the unprecedented coordination polymeric architectures. The ESR spectroscopic results, conductivity, and synthesis properties are also discussed.

Spiral, herringbone, and triple-decker silver(I) complexes of benzopyrene derivatives assembled through eta(2)-coordination

Three novel silver(I) complexes with benzopyrene derivatives were synthesized and characterized in this paper. Treatment of AgClO(4)*H(2)O with 7-methylbenzo[a]pyrene (L(1)) afforded [Ag(2)(L(1))(toluene)(0.5)(ClO(4))(2)](n)() (1) which exhibits a 2-D sheet structure with double-stranded helical motifs. Reaction of AgCF(3)SO(3) with dibenzo[b,def ]chrysene (L(2)) gave rise to an unprecedented cocrystallization structure, ([Ag(2)(L(2))(CF(3)SO(3))(2)][Ag(2)(toluene)(2)(CF(3)SO(3))(2)])(n)() (2), formed by a 2-D neutral lamellar polymer and a 1-D neutral rodlike one. The ligand benzo[e]pyrene (L(3)) coordinated to silver(I) ions generating a closed triple-decker tetranuclear complex [Ag(4)(L(3))(4)(p-xylene)(ClO(4))(4)] (3) which can be regarded as a stacking polymer owing to existing intermolecular pi-pi stack interactions. The structural diversity of the silver(I) coordination polymers with polycyclic aromatic hydrocarbons is not only related to the stacking patterns of free polycyclic aromatic hydrocarbons in the crystalline state, but also the geometric shapes of the molecules for these free ligands. In addition, the coordination of solvents to metal ions plays a crucial role in the formation of the unprecedented coordination polymeric architectures. The ESR spectroscopic results, conductivity, and synthesis properties are also discussed.

Neonatally administered diethylstilbestrol retards the development of the blood-testis barrier in the rat

Newborn rats were treated with 10 microg of diethylstilbestrol (DES) on alternate days from the 2nd to the 12th postnatal day, and the testes were sequentially examined up to 105 days of age by light, electron, and confocal laser microscopy. In control rats, spermatozoa and step 19 spermatids were observed in stage VIII seminiferous tubules at 56 days of age. Spermatogenic cells in DES-treated rats differentiated normally from birth until 21 days of age, after which differentiation continued only to the pachytene-spermatocyte stage. From this age onward, spermatogenic cells older than pachytene spermatocytes were not found until 56 days of age. After this point, the cells resumed differentiation and finally became spermatozoa by 91 days of age; that is, 35 days later than control rats. Electron and confocal laser microscopy showed that in the normal rat, the formation of the ectoplasmic specialization between adjoining Sertoli cells was observed as early as 20 days of age. In contrast, the specialization was not formed until 56 days of age in DES-treated rats. Furthermore, the delay in functional maturation of this structure as the blood-testis barrier was confirmed by intercellular tracer experiments. It is clear that neonatal administration of DES delayed the establishment of the blood-testis barrier for 4 weeks. Consequently, during this period, pachytene spermatocytes were exfoliated from the seminiferous epithelium without completion of meiosis.

Relationship between triglyceride concentrations and LDL size evaluated by malondialdehyde-modified LDL

BACKGROUND

Hypertriglyceridemia is associated with decreased HDL-cholesterol (HDL-C) and increased small dense LDL. In addition, small dense LDL is known to be susceptible to oxidation.

METHODS

We measured LDL particle size, using gradient gel electrophoresis, and malondialdehyde-modified LDL (MDA-LDL), using an ELISA, and investigated the association between triglyceride (TG) concentrations, LDL size, and MDA-LDL.

RESULTS

TG concentrations correlated negatively with the predominant LDL size (r = -0.650) and HDL-C concentration (r = -0.556). The relationship between TG concentration and LDL size, evaluated by measuring MDA-LDL, distinguished subgroups derived from four subfractions of TG concentrations and four distribution ranges of LDL size. These experiments indicated that there is a threshold for oxidation susceptibility at an LDL size of 25.5 nm and a TG concentration of 1500 mg/L. To investigate the relationship between LDL size, MDA-LDL concentration, and other lipids (TGs, HDL-C, apolipoprotein B, and total cholesterol), we evaluated them in control subjects and patients with diabetes mellitus or hypertriglyceridemia. When the size range for normal LDL was postulated to be 25.5 < or = phi (LDL diameter) < 26.5 nm, the MDA-LDL concentration was significantly higher in the subgroups of patients with LDL in the size range 24.5 < or = phi < 25.5 nm compared with patients with normal LDL. This result also suggests that the threshold is at a LDL size of 25.5 nm.

CONCLUSION

The threshold for oxidation susceptibility coincided with the point of LDL size separation between the LDL subclass patterns A and B as an atherosclerotic risk.

Involvement of noradrenaline transporters in S-nitrosocysteine-stimulated noradrenaline release from rat brain slices: existence of functional Na(+)-independent transporter activity

Noradrenaline (NA) can be released by both exocytosis and by the membrane transporter responsible for transmitter uptake. Previously, we reported that S-nitrosocysteine (SNC), an S-nitrosothiol, stimulated [3H]NA release from the rat hippocampus. In this study, we investigated the involvement of the NA transport system in SNC-stimulated NA release from rat brain (cerebral cortex and hippocampus) slices. [3H]NA release by SNC in normal Na(+) (148 mM)-containing buffer from both slices was slightly, but significantly, inhibited by 1 microM desipramine, an NA transporter inhibitor. [3H]NA release in low Na(+) (under 14 mM)-containing buffer was inhibited by over 50% by desipramine. [3H]NA release by tyramine from both slices in normal and low Na(+) buffer was almost completely inhibited by desipramine. [3H]NA uptake into cerebral cortical slices was observed in low Na(+) buffer at 20-30% of normal Na(+) buffer levels. [3H]NA uptake in both normal and low Na(+) buffers was inhibited by desipramine and by SNC. Although [3H]NA uptake in normal Na(+) buffer was almost completely inhibited by 500 microM ouabain, the uptake in low Na(+) buffer was resistant to ouabain. These findings suggest the existence of a functional Na(+)-independent NA transport system and that SNC stimulates NA release at least partially via this system in brain slices.

The LAX1 and FRIZZY PANICLE 2 genes determine the inflorescence architecture of rice by controlling rachis-branch and spikelet development

We have analyzed two mutants that exhibit altered panicle architecture in rice (Oryza sativa L.). In lax1-2, which is a new and stronger allele of the previously reported lax mutant, initiation and/or maintenance of rachis-branches, lateral spikelets, and terminal spikelets was severely prevented. In situ hybridization analysis using OSH1, a rice knotted1 (kn1) ortholog, confirmed the absence of lateral meristems in lax1-2 panicles. These defects indicate that the LAX1 gene is required for the initiation/maintenance of axillary meristems in the rice panicle. In addition to its role in forming lateral meristems, the wild-type LAX1 gene acts as a floral meristem identity gene which specifies the terminal spikelet meristem. A comparison of the defects in lax1-1 and lax1-2 plants suggested that the sensitivities to reduced LAX1 activity were not uniform among different types of meristems. In the fzp2 mutant panicle, the basic branching pattern of the panicle was indistinguishable from that of the wild type; however, specification of both terminal and lateral spikelet meristems was blocked, and sequential rounds of branching occurred at the point where the spikelet meristems are initiated in the wild-type panicle. This resulted in the generation of a panicle composed of excessive ramification of rachis-branches. The lax1-1 fzp2 double mutants exhibited a novel, basically additive, phenotype, which suggests that LAX1 and FZP2 function in genetically independent pathways.

[EDAS (encephalo-duro-arterio-synangiosis) for occlusive/stenotic cerebrovascular disease]

The efficacy of encephalo-duro-arterio-synangiosis (EDAS) using superficial temporal artery was evaluated for the treatment of the occlusive/stenotic cerebrovascular disease. Nine patients with the occlusive/stenotic cerebrovascular disease underwent EDAS in our hospital. The mean follow-up period was 6.6 months. Postoperative angiography showed no collateral formation via EDAS in any of the nine patients. We analyzed the following points: 1) operative procedure, 2) follow up period after surgery, 3) preoperative cerebral blood flow, and 4) age of the patients. Results showed that EDAS as a treatment of occlusive/stenotic cerebrovascular disease was not effective. This study failed to reinforce the suggestion that indirect extracranial/intracranial bypass surgery is effective as the treatment of occlusive/stenotic cerebrovascular disease.

Heterogeneity of DNA methylation status analyzed by bisulfite-PCR-SSCP and correlation with clinico-pathological characteristics in colorectal cancer

Aberrant DNA methylation has been identified as an important mechanism for inactivation of tumor suppressor genes and mismatch repair genes during carcinogenesis. We used bisulfite treatment and the PCR-single strand conformation polymorphism (SSCP) (BiPS) technique to analyze methylation status of the promoter regions of the hMLH1, p16, and HIC1 genes in several cancer cell lines and colorectal cancer tissues. The methylation of the hMLH1, p16 and HIC1 genes was observed in 2, 8, and 13 of 13 cancer cell lines, respectively. The SSCP for p16 and HIC1 in each of the methylation-positive cell lines were similar, indicating relative homogeneity of methylation status and complete methylation in the cell lines. Methylation was observed in 8, 5, and 21 of 25 colorectal cancer tissues for the hMLH1, p16, and HIC1 genes, respectively. The methylated bands revealed by BiPS analysis of the hMLH1 gene were homogeneous, whereas those of the p16 and HIC1 genes were different in each case. The methylation of the promoter region of the HIC1 gene in colorectal cancer was observed most frequently and could serve as a sensitive marker for colorectal cancer. Methylation status of the hMLH1 and p16 gene promoters was correlated with microsatellite instability status, tumor location, and differentiation but not with K-ras mutation or allelic loss of p53.

[Genetic polymorphism and cancer]

The clinical pathological significance of genetic polymorphism in cancer is reviewed from the following standpoint. 1) Genetic diagnosis of cancer, especially for loss of heterozygosity 2) Interference with laboratory data: For example, the polymorphisms in secretor and Lewis genes make effect on the serum levels of CA19-9. 3) Cancer susceptibility: Molecular epidemiological studies revealed some genetic polymorphisms were related with cancer susceptibility and were useful for biomarkers of cancer risk. 4) Drug sensitivity: The differences in drug toxicity are sometimes attributed to genetic variability in some enzymes responsible for drug metabolism. When the polymorphisms related with drug degradation were examined, the exact drug would have been selected for each individual. Genetic polymorphisms are strongly related with clinical practice of cancer. After the information about genetic polymorphisms is accumulated, tailor-made medicine(therapy/prevention/diagnosis) will be applicable to medical care of individuals.

Effects of S-nitroso-cysteine on proteins that regulate exocytosis in PC12 cells: inhibitory effects on translocation of synaptophysin and ADP-ribosylation of GTP-binding proteins

S-Nitroso-cysteine (SNC) inhibits Ca2+-induced noradrenaline (NA) release from PC12 cells. Since SNC stimulated Ca2+ mobilization from intracellular Ca2+ pools and SNC-induced inhibition of NA release was not washed-out, SNC may modify exocytosis-related proteins that overcome Ca2+ mobilization. In the present study, we investigated the effects of SNC on exocytosis-related proteins in PC12 cells. Ionomycin stimulated NA release and increased the immunoreactivity of synaptophysin in the cytosol fraction. A 25-kDa synaptosome-associated protein (SNAP-25), which localizes to plasma membranes and vesicles, increased in the cytosol fraction after stimulation. The increases in these proteins by ionomycin were inhibited in PC12 cells treated with 0.6 mM SNC. Synaptobrevin and synapsin-1 in the cytosol fraction, and syntaxin and 43 kDa growth-associated protein in the membrane fraction were not affected by ionomycin or SNC. Incubation of each protein with SNC did not affect antibody immunoreactivity. [32P]ADP-ribosylation of GTP-binding proteins (Gi/Go) by pertussis toxin, but not Gs by cholera toxin, was inhibited in SNC-treated PC12 cells and by co-addition of SNC to the assay mixture. These findings suggest that 1) SNC inhibits translocation of vesicles containing synaptophysin and SNAP-25, and 2) SNC reacts with cysteine residues in Gi/Go, causing inhibition of ADP-ribosylation by pertussis toxin.

Hypertriglyceridemia characterized by low-density lipoprotein phenotype and lipoprotein lipase gene mutation

A high serum triglyceride (TG) concentration is associated with an increased serum concentration of small, dense low-density lipoprotein (LDL). To further characterize the hypertriglyceridemic condition, we examined sera from 240 subjects for small, dense LDL using non-denaturing polyacrylamide gradient gel electrophoresis. We focused on determining the frequency of the pattern B, which is characterized by a higher proportion of small, dense LDL, among hypertriglyceridemic individuals. The subjects were divided into four groups: a control group (TG < or = 1.65 mmol/l, high-density lipoprotein cholesterol (HDL-C) > or =1.17 mmol/l; n = 71), a high TG group (TG > 1.65 mmol/l, HDL-C > or = 1.17 mmol/l; n = 36), a group with high TG and low HDL-C (TG > 1.65 mmol/l, HDL-C < or = 0.91 mmol/l; n = 106), and a low HDL-C group (TG < or = 1.65 mmol/l, HDL-C < or = 0.91 mmol/l; n = 27). We found that pattern B occurs at a high frequency mainly in individuals with high TG and low HDL-C levels. We also observed an increased percentage of LDL within the 20.0 nm to 25.5 nm particle diameter range in this group. Analysis of the lipoprotein lipase gene in this group showed that some mutations seem to be associated with small, dense LDL, resulting in LDL pattern B.

Bridged silver(I) complexes of the polycyclic aromatic compounds tetraphenylethylene and 1,1,4,4-tetraphenyl-1,3-butadiene

For the purpose of investigating the coordination behavior of the sterically congested alkenes and exploring the possibility of cofacial complexation in the polycyclic aromatic system for formation of extended polymeric networks, tetraphenylethylene (tphe) and 1,1,4,4-tetraphenyl-1,3-butadiene (tphb) have been studied with regard to their complexation with a silver(I) ion. The crystal structures of [Ag(tphe)(ClO4)(p-xylene)], [Ag2(tphe)(ClO4)2], [Ag4(tphe)(CF3SO3)4], [Ag2(tphb)(ClO4)2], and [Ag2(tphb)(CF3SO3)2], together with the metal-free ligands tphe and tphb, have been determined by single-crystal X-ray diffraction. The pi-electron-rich cleft in organic components is found to offer a potential site for complexation, which can be utilized to generate an interesting array of organometallic compounds with one- and two-dimensional frameworks.

2-D interwoven and 3-D 5-fold interpenetrating silver(I) complexes of 1-(isocyanidomethyl)-1H-benzotriazole and 1,3-bis(dicyanomethylidene)indan

This paper presents novel and distinctive organosilver polymers with intriguing structure motifs, constructed from iodoacetonitrile (L1), 1-(isocyanidomethyl)-1H-benzotriazole (L2), 1,3-bis(dicyanomethylidene)indan (L3), and silver(I) salts, respectively. Treatment of L1 with AgClO4 generated [Ag(L1)(ClO4)]n (1), whose X-ray determination revealed a 2-D wavy sheet structure with square grids. Reaction of L2 with AgPF6 gave rise to a novel 2-D wavy interwoven network, ([Ag(L2)(PO2F2)0.5])n (2). The complex [Ag2(L3)2]n (3) obtained by reaction of AgClO4 with L3 can be regarded as unprecedented 3-D 5-fold interpenetrating nets with columnar aromatic stacks and indicates semiconductive behavior. The IR, ESR spectroscopic results, conductivities, and structural features of the complexes are discussed, respectively. The present findings may provide insight into the coordination versatility of silver(I) and polynitrile ligands and an inspiration for the self-assembly of novel supramolecular networks with multifunctional ligands. Crystal data: 1, C2H2AgINClO4, orthorhombic, Pca2(1) (No. 29), a = 14.503(1) A, b = 5.104(2) A, c = 10.2019(9) A, Z = 4; 2, C8H6AgN4PF4O, orthorhombic, Pnna (No. 52), a = 12.2705(3) A, b = 21.150(1) A, c = 10.040(1) A, Z = 8; 3, C30H10Ag2N8, triclinic, P1 (No. 2), a = 14.920(2) A, b = 11.896(2) A, c = 7.400(4) A, alpha = 86.55(2) degrees, beta = 80.87(2) degrees, gamma = 74.47(1) degrees, Z = 2.

Primary pulmonary hypertension with central sleep apnea: sudden death after bilevel positive airway pressure therapy

An obese 23-year-old man with sleep-disordered breathing and primary pulmonary hypertension (PPH) had been administered oral beraprost sodium, anticoagulant warfarin, and home oxygen therapy, at another hospital as treatment for the PPH, but he had not experienced any symptomatic improvement. The patient had a body mass index of 32.4kg/m2, and complained of fatigue, shortness of breath on exertion, excessive daytime sleepiness, and snoring. Arterial blood gas analysis showed a PaO2 and a PaCO2 of 70.9 and 31.2mmHg, respectively. A polysomnographic study revealed central sleep apnea with an apnea-hypopnea index (AHI) of 29.7episodes/h. The patient showed improvement of daytime sleepiness after starting nocturnal nasal bilevel positive airway pressure (BiPAP) therapy for the central sleep apnea, but his pulmonary hypertension, measured in the daytime, worsened. The patient died suddenly while walking to the bathroom in the morning 1 month after initiation of BiPAP therapy. It is necessary to consider the possibility of sudden death when nasal BiPAP therapy is given to a PPH patient with central sleep apnea.

[Sleep apnea syndrome (SAS) and ischemic heart disease (IHD)]

Several epidemiological studies have suggested that sleep-disordered breathing is a risk factor for cardiovascular disease, particularly hypertension, stroke and IHD. The relative risk for IHD among obstructive SAS(OSAS) patients is 1.2 to 6.9 higher compared with the general population. The prevalence of SAS with an apnea-hypopnea index(AHI) of 10 and over was 35 to 40% in IHD, while 23.8% of SAS patients had IHD. These evidence suggests that IHD is an important prognostic factor in SAS patients. Characteristic pathophysiological conditions such as sleep apnea-induced hypoxemia and sympathetic activation may play an important role in the genesis of nocturnal angina pectoris. Most patients with OSAS are obese, and the complication of non-insulin dependent diabetes mellitus is quite a few. Insulin resistance is also attracting great attention as a cause of the cardiovascular complication of SAS.

[A case of hemophagocytosis syndrome with excessive Fe and ferritin concentration in serum and with a good prognosis]

Investigation in the present case began with a high serum Fe concentration. The routine method for determining serum Fe concentration in our hospital is direct photoscopic assay. When we assayed serum Fe concentration by a deproteinization method, it showed a higher value. We also measured serum ferritin concentration, and suspected that high ferritin interfered with serum Fe concentration. We checked the dose-dependent effect of ferritin on serum Fe determination. The present case, a 64-year-old female, showed a reduction of Plt count, and an elevation of LDH, CRP and so on, meeting most of the criteria for hemophagocytosis syndrome. Bone marrow smears revealed phagocytosis of blood cells. The present case had been followed for rheumatoid arthritis and medicated with oral iron pills. In her liver and spleen, high amounts of Fe had accumulated, and excessive Fe was being released into the blood by any trigger, such as infection, stress, cytokine activation, and/or HPS.

Sleep apnea syndrome in patients with pulmonary thromboembolism

Seven patients (one man and six women) with a diagnosis of pulmonary thromboembolism (PTE) were examined by polysomnography in order to clarify the relationship between sleep-related breathing disorders and PTE. In the chronic stage of PTE, sleep apnea syndrome (SAS) was recognized in two patients (a man and a woman) among the subjects. Four of the five patients without SAS showed nocturnal hypoxemia. The female predominance was different from ordinary SAS without the disease background of PTE even though PTE is accompanied by hypoxemia and pulmonary hypertension like SAS. A pathophysiological relationship between PTE and SAS was not found in this study.

Structural studies of silver(I) coordination polymers with aryl iodide derived ligands

This paper reports novel silver polymers, built with iodine--silver interactions, with interesting structural motifs. Four silver(I) coordination polymers of the aryl iodide derived ligands, triiodobenzoic acid (HL1), tris(4-iodophenyl)amine (L2), and 5,7-diiodo-8-hydroxyquinoline (HL3), have been synthesized and characterized by X-ray crystallography. Treatment of Ag(CH3COO) with HL1 yielded [Ag(L1)] (1), whose structural analysis revealed 2D layers of ladders connected through weak Ag...I interaction. Reactions of AgClO4 and L2 in benzene and nitrobenzene afforded, respectively, two different products, [Ag(L2)(H2O)]ClO4.C6H6(2) and [Ag(L2)(ClO4)](3). While the structure of 2 could be described as a 2D layer of square and octagons perpendicular to [100], complex 3 is formed by 2D layers of the same topology of 2 (8(2).4), alternating as ABAB. In contrast, complex 4, [Ag2(H2L3)(CF3SO3)3], obtained by reaction of Ag(CF3SO3) and HL3, was found to consist of a 2D layer based on columnar arrays AgH2L3-Ag(triflate). The solid-state FT-IR and 109Ag NMR spectra of theses complexes are discussed on the basis of their crystal structures.

A critical role for a Rho-associated kinase, p160ROCK, in determining axon outgrowth in mammalian CNS neurons

We tested the contribution of the small GTPase Rho and its downstream target p160ROCK during the early stages of axon formation in cultured cerebellar granule neurons. p160ROCK inhibition, presumably by reducing the stability of the cortical actin network, triggered immediate outgrowth of membrane ruffles and filopodia, followed by the generation of initial growth cone-ike membrane domains from which axonal processes arose. Furthermore, a potentiation in both the size and the motility of growth cones was evident, though the overall axon elongation rate remained stable. Conversely, overexpression of dominant active forms of Rho or ROCK was suggested to prevent initiation of axon outgrowth. Taken together, our data indicate a novel role for the Rho/ROCK pathway as a gate critical for the initiation of axon outgrowth and the control of growth cone dynamics.

Pharmacological properties of Y-27632, a specific inhibitor of rho-associated kinases

Y-27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide++ + dihydrochloride] is widely used as a specific inhibitor of the Rho-associated coiled-coil forming protein serine/threonine kinase (ROCK) family of protein kinases. This study examined the inhibition mechanism and profile of actions of Y-27632 and a related compound, Y-30141 [(+)-(R)-trans- 4-(1-aminoethyl)-N-(1H-pyrrolo[2, 3-b]pyridin-4-yl)cyclohexan-ecarboxamide dihydrochloride]. Y-27632 and Y-30141 inhibited the kinase activity of both ROCK-I and ROCK-II in vitro, and this inhibition was reversed by ATP in a competitive manner. This suggests that these compounds inhibit the kinases by binding to the catalytic site. Their affinities for ROCK kinases as determined by K(i) values were at least 20 to 30 times higher than those for two other Rho effector kinases, citron kinase and protein kinase PKN. [(3)H]Y-30141 was taken up by cells in a temperature- and time-dependent and saturable manner, and this uptake was competed with unlabeled Y-27632. No concentrated accumulation was found, suggesting that the uptake is a carrier-mediated facilitated diffusion. Y-27632 abolished stress fibers in Swiss 3T3 cells at 10 microM, but the G(1)-S phase transition of the cell cycle and cytokinesis were little affected at this concentration. Y-30141 was 10 times more potent than Y-27632 in inhibiting the kinase activity and stress fiber formation, and it caused significant delay in the G(1)-S transition and inhibition of cytokinesis at 10 microM.

Learning deficiency and alterations in acetylcholine receptors and protein kinase C in the brain of senescence-accelerated mouse (SAM)-P10

The senescence-accelerated mouse (SAM) is known to be a murine model for accelerated aging. A novel inbred SAMP10 has shown age-related brain atrophy and learning deficiency. In the present study, we investigated the changes in learning ability and in ligand binding with muscarinic acetylcholine (mACh) receptors, alpha adrenoceptors and protein kinase C in SAMP10. In Morris's water maze task, in a control strain of SAMR1 at 9 months, the escape latency and path length decreased with increasing trial days, in contrast, escape latency and path length did not decrease in SAMP10. These results indicate that SAMP10 exhibits learning deficiency. The ligand binding activity of mACh receptors decreased in the hippocampus of SAMP10 and the protein kinase C level in the hippocampus of SAMP10 was lower than that of SAMR1. On the other hand, there was no significant difference between SAMR1 and SAMP10 regarding ligand binding activity of alpha(1) and alpha(2) adrenoceptors. Thus, a reduction of mACh receptors and protein kinase C in the brain seems to underlie dysfunction of learning and memory in SAMP10.

Involvement of Hg2+-sensitive sulfhydryl groups in regulating noradrenaline release induced by S-nitrosocysteine in rat brain slices

Nitric oxide has been shown to regulate neurotransmitter release. Previously, we reported that S-nitrosothiols such as S-nitrosocysteine (SNC) stimulate noradrenaline (NA) release in rat hippocampus in vivo and in vitro. To examine the role of sulfhydryl groups in SNC-induced NA release, the effects of metal ions such as Hg2+ and N-ethylmaleimide (NEM, a sulfhydryl alkylating agent) on [3H]NA release from labeled rat brain slices (hippocampus and cerebral cortex) were studied and compared with the effects of SNC. The addition of 200 microM HgCl2, but not Pb2+, Zn2+, or Cd2+, stimulated [3H]NA release from both types of slices in the presence of extracellular CaCl2. p-Chloromercuribenzoic acid (p-CMBA) also stimulated [3H]NA release. NEM stimulated [3H]NA release from both types of slices in the presence and absence of extracellular CaCl2. The effect of 200 microM NEM was enhanced, but the effect of 200 microM SNC was inhibited by co-addition of 200 microM p-CMBA in the absence of extracellular CaCl2. The concentration-response curve of SNC shifted to the right after co-addition of 200 microM p-CMBA or 100 microM HgCl2, although the effect of 200 microM NEM was additive to the effect of SNC. These findings demonstrate that SNC acts as a sulfhydryl agent on proteins that regulate NA release, and that SNC may share the same sulfhydryl groups with Hg compounds. The effect of T-588 ¿(R)-(-)-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy]eth anol hydrochloride¿, a novel cognitive enhancer and a stimulator of NA release, was compared with the effects of sulfhydryl reagents.

Evaluation of a nonstarch polysaccharidase feed enzyme in dairy cow diets

The objective of this study was to evaluate a commercial feed enzyme product (Natugrain 33-L; BASF Corporation, Ludwigshafen, Germany) used mainly in poultry diets for use in ruminant diets. The product contained mainly beta-glucanase, xylanase, and endocellulase activities. The study was conducted as a double 3 x 3 Latin square design with six lactating dairy cows (84 +/- 12 DIM) to measure intake, chewing activities, total tract digestion, and milk production. An additional three cows fitted with ruminal cannulae were used to measure dietary effects on ruminal fermentation and in sacco digestion characteristics. Cows received a diet consisting of 45% forage containing 0, 1.22, or 3.67 L of enzyme product/tonne of total mixed ration (DM basis). Using a low or high concentration of enzyme supplementation increased feed intake, but total tract digestibility only increased with the low concentration of enzyme. As a result, intake of digestible nutrients was increased to a greater extent for cows fed the low concentration than for cows fed the high concentration. Because the cows used in this experiment were in positive energy balance, increased intake of digestible energy due to enzyme supplementation did not increase milk yield or milk component yield. Further research is necessary to determine the mechanism by which adding a fibrolytic enzyme mixture enhanced intake, but only increased feed digestion when used at a low level.