FoxO1 signaling plays a pivotal role in the cardiac telomere biology responses to calorie restriction.

This study examined whether the forkhead transcription factors of O group 1 (FoxO1) might be involved in telomere biology during calorie restriction (CR). We used FoxO1-knockout heterozygous mice (FoxO1(+/-)) and wild-type mice (WT) as a control. Both WT and FoxO1(+/-) were subjected to ad libitum (AL) feeding or 30% CR compared to AL for 20 weeks from 15 weeks of age. The heart-to-body weight ratio, blood glucose, and serum lipid profiles were not different among all groups of mice at the end of the study. Telomere size was significantly lower in the FoxO1(+/-)-AL than the WT-AL, and telomere attrition was not observed in either WT-CR or FoxO1(+/-)-CR. Telomerase activity was elevated in the heart and liver of WT-CR, but not in those of FoxO1(+/-)-CR. The phosphorylation of Akt was inhibited and Sirt 1 was activated in heart tissues of WT-CR and FoxO1(+/-)-CR. However, the ratio of conjugated to cytosolic light chain 3 increased and the level of p62 decreased in WT-CR, but not in FoxO1(+/-)-CR. A marker of oxidative DNA damage, 8-OhdG, was significantly lower in WT-CR only. The level of MnSOD and eNOS increased, and the level of cleaved caspase-3 decreased in WT-CR, but not FoxO1(+/-)-CR. Echocardiography showed that the left ventricular end-diastolic and systolic dimensions were significantly lower in WT-CR or FoxO1(+/-)-CR than WT-AL or FoxO1(+/-)-AL, respectively. The present studies suggest that FoxO1 plays beneficial roles by inducing genes involved in telomerase activity, as well as anti-oxidant, autophagic, and anti-apoptotic genes under conditions of CR, and suggest that FoxO1 signaling may be an important mediator of metabolic equilibrium during CR.

Ras-related C3 botulinum toxin substrate 1 (RAC1) regulates glucose-stimulated insulin secretion via modulation of F-actin.

AIMS/HYPOTHESIS: The small G-protein ras-related C3 botulinum toxin substrate 1 (RAC1) plays various roles in mammalian cells, such as in the regulation of cytoskeletal organisation, cell adhesion, migration and morphological changes. The present study examines the effects of RAC1 ablation on pancreatic beta cell function. METHODS: Isolated islets from pancreatic beta cell-specific Rac1-knockout (betaRac1(-/-)) mice and RAC1 knockdown INS-1 insulinoma cells treated with small interfering RNA were used to investigate insulin secretion and cytoskeletal organisation in pancreatic beta cells. RESULTS: BetaRac1(-/-) mice showed decreased glucose-stimulated insulin secretion, while there were no apparent differences in islet morphology. Isolated islets from the mice had blunted insulin secretion in response to high glucose levels. In RAC1 knockdown INS-1 cells, insulin secretion was also decreased in response to high glucose levels, consistent with the phenotype of betaRac1(-/-) mice. Even under high glucose levels, RAC1 knockdown INS-1 cells remained intact with F-actin, which inhibits the recruitment of the insulin granules, resulting in an inhibition of insulin secretion. CONCLUSIONS/INTERPRETATION: In RAC1-deficient pancreatic beta cells, F-actin acts as a barrier for insulin granules and reduces glucose-stimulated insulin secretion.

GST polymorphisms, interaction with smoking and pesticide use, and risk for Parkinson's disease in a Japanese population.

Patients with idiopathic Parkinson's disease (PD) appear to have reduced capacity for detoxification of certain environmental compounds. The glutathione S-transferases (GSTs) are candidate genes for PD because they are involved in the metabolism of pesticides and cigarette smoke. We investigated the relationship of the seven GST polymorphisms (GSTM1 deletion, GSTT1 deletion, GSTP1 rs1695, GSTO1 rs4925, GSTO1 rs11191972, GSTO2 rs156697 and GSTO2 rs2297235) and PD risk with special reference to the interaction with pesticide use or cigarette smoking among 238 patients with PD cases and 370 controls in a Japanese population. None of the GST polymorphisms were associated with PD. GSTO1 rs4925 and GSTO2 rs2297235 were found to be in strong linkage disequilibrium (D' = 0.98). Cigarette smoking was significantly associated with decreased risk of PD. However, no interaction of smoking with any of the GST polymorphisms was observed. Self-reported pesticide use was not associated with increased risk of PD. There was no evidence of interaction between self-reported pesticide use and either GST polymorphism. Our results suggest that the tested GST polymorphisms did not play an important role in PD susceptibility in our Japanese population. Our study does not give evidence of interaction between the GST polymorphisms and smoking may although this study provided sufficient statistical power to detect modest interaction. As for interaction between GSTP polymorphisms and pesticide use, the power of this study to detect an interactive effect was low due to a small number of pesticide users. Future studies involving larger control and case populations and better pesticide exposure histories will undoubtedly lead to a more thorough understanding of the role of the GST polymorphisms in PD development.

[Mediastinal emphysema after a punch on the back; report of a case].

A 19-year-old man was punched on the back, and anterior chest pain appeared about 3 hours after injury. The patient was consulted a physician complaining of anterior chest pain. On chest X-ray, mediastinal emphysema was suspected, and transferred to our hospital. Chest computed tomography (CT) revealed mediastinal emphysema. On esophageal radiography and bronchofiberscopy, no abnormal findings were detected. Conservative therapy was conducted, and symptoms had gradually improved. On the 8th hospital day, mediastinal emphysema was improved on chest CT. The patient was discharged on the 10th hospital day. The most frequent cause of mediastinal emphysema after trauma is traffic or downfall accident, and no report on this condition after the punch on the back was found.

Genetic characterization of non-spoilage variant isolated from beer-spoilage Lactobacillus brevis ABBC45.

AIMS: To characterize the non-spoilage variant obtained from beer-spoilage Lactobacillus brevis ABBC45C and to identify a potential genetic marker capable of discriminating beer-spoilage L. brevis strains from non-spoilers. METHODS AND RESULTS: A non-spoilage variant was obtained from beer-spoilage L. brevis ABBC45C by repeatedly subculturing the strain at 37 degrees C. Genetic characterization of the variant revealed that 12,605 bp portion of one plasmid, designated pRH45II, was lost in the variant. The sequence analysis indicates the presence of 12 ORFs in the deleted region of pRH45II. The PCR and Southern hybridization study revealed that the homologues of ORF5 found in the deleted region were present in all of the beer-spoilage L. brevis strains examined in this study. In contrast, the homlogues appeared to be absent in non-spoilage L. brevis strains. CONCLUSIONS: The presence or absence of ORF5 homologues was found to be highly correlated with the beer-spoilage ability of L. brevis strains, indicating this ORF is potentially a useful genetic marker capable of differentiating beer-spoilage strains among L. brevis. SIGNIFICANCE AND IMPACT OF THE STUDY: A non-spoilage variant was successfully isolated from beer-spoilage L. brevis ABBC45C. This study could facilitate the understanding of mechanisms underlying beer-spoilage ability of L. brevis.

Genetic characterization and specific detection of beer-spoilage Lactobacillus sp. LA2 and related strains.

AIMS: Lactobacillus sp. LA2 (DSM15502) and related strains (LA2 group) possess strong beer-spoilage ability. The 16S rDNA sequence of LA2 strain is virtually indistinguishable from that of L. collinoides, generally considered to be nonbeer-spoilage bacteria. The aim of this study was to identify the genetic marker to distinguish between Lactobacillus sp. LA2 group and L. collinoides and to provide a rapid means of identifying beer-spoilage strains belonging to Lactobacillus sp. LA2 group. METHODS AND RESULTS: The 16-23S rDNA intergenic spacer (ITS) regions of Lactobacillus sp. LA2 and L. collinoides JCM1123T were sequenced to identify a genetic marker to distinguish between the two groups. As a result, 300 and 500 bp ITS regions of Lactobacillus sp. LA2 were found to be almost identical with those of L. collinoides JCM1123T. Sequence comparison analysis between Lactobacillus sp. LA2 and L. collinoides JCM1123T revealed that the two contiguously located nucleotides are absent in both ITS regions of Lactobacillus sp. LA2. Based on the sequence difference, we have designed specific PCR primers with a minor modification to the primer sequence that can differentiate between beer-spoilage Lactobacillus sp. LA2 group and nonbeer-spoilage L. collinoides. CONCLUSIONS: The PCR-based method has been developed to identify Lactobacillus sp. LA2 group, providing a rapid and sensitive means of determining the beer-spoilage ability of detected bacterial strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The substitution of one nucleotide, located at the third position to the 3'-end in the primer sequence, enhanced the specificity of the PCR method while retaining sufficient sensitivity. The nucleotide gap identified in this study appeared to serve as a useful genetic marker that can differentiate 12 beer-spoilage Lactobacillus sp. LA2 group strains from its close relatives that exhibit no beer-spoilage ability.

Antiinflammatory and antiarteriosclerotic actions of HMG-CoA reductase inhibitors in a rat model of chronic inhibition of nitric oxide synthesis.

Recent studies suggest that some of the beneficial effects of 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) may be due to their cholesterol-lowering independent effects on the blood vessels. Chronic inhibition of endothelial nitric oxide (NO) synthesis by oral administration of N(omega)-nitro-L-arginine methyl ester (L-NAME) to rats induces early vascular inflammation as well as subsequent arteriosclerosis. The aim of the study is to test whether treatment with statins attenuates such arteriosclerotic changes through their cholesterol-lowering independent effects. We investigated the effect of statins (pravastatin and cerivastatin) on the arteriosclerotic changes in the rat model. We found that treatment with statins did not affect serum lipid levels but markedly inhibited the L-NAME-induced vascular inflammation and arteriosclerosis. Treatment with statins augmented endothelial NO synthase activity in L-NAME-treated rats. We also found the L-NAME induced increase in Rho membrane translocation in hearts and its prevention by statins. Such vasculoprotective effects of statins were suppressed by the higher dose of L-NAME. In summary, in this study, we found that statins such as pravastatin and cerivastatin inhibited vascular inflammation and arteriosclerosis through their lipid-lowering independent actions in this model. Such antiarteriosclerotic effects may involve the increase in endothelial NO synthase activity and the inhibition of Rho activity.

New anti-monocyte chemoattractant protein-1 gene therapy attenuates atherosclerosis in apolipoprotein E-knockout mice.

BACKGROUND: Monocyte recruitment into the arterial wall and its activation may be the central event in atherogenesis. Monocyte chemoattractant protein-1 (MCP-1) is an important chemokine for monocyte recruitment, and its receptor (CCR2) may mediate such in vivo response. Although the importance of the MCP-1/CCR2 pathway in atherogenesis has been clarified, it remains unanswered whether postnatal blockade of the MCP-1 signals could be a unique site-specific gene therapy. METHODS AND RESULTS: We devised a new strategy for anti-MCP-1 gene therapy to treat atherosclerosis by transfecting an N-terminal deletion mutant of the human MCP-1 gene into a remote organ (skeletal muscle) in apolipoprotein E-knockout mice. This strategy effectively blocked MCP-1 activity and inhibited the formation of atherosclerotic lesions but had no effect on serum lipid concentrations. Furthermore, this strategy increased the lesional extracellular matrix content. CONCLUSIONS: We conclude that this anti-MCP-1 gene therapy may serve not only to reduce atherogenesis but also to stabilize vulnerable atheromatous plaques. This strategy may be a useful and feasible form of gene therapy against atherosclerosis in humans.

Regression by ACE inhibition of arteriosclerotic changes induced by chronic blockade of NO synthesis in rats.

We previously reported that chronic inhibition of nitric oxide (NO) synthesis with N(omega)-nitro-L-arginine methyl ester (L-NAME) induces vascular inflammation at week 1 and produces subsequent arteriosclerosis at week 4 and that cotreatment with an angiotensin-converting enzyme (ACE) inhibitor prevents such changes. In the present study, we tested the hypothesis that treatment with an ACE inhibitor after development of vascular inflammation could inhibit arteriosclerosis in rats. Wistar-Kyoto rats were randomized to four groups: the control group received no drugs, the 4wL-NAME group received L-NAME (100 mg x kg(-1) x day(-1)) for 4 wk, the 1wL + 3wNT group received L-NAME for 1 wk and no treatment for the subsequent 3 wk, and the 1wL + 3wACEI group received L-NAME for 1 wk and the ACE inhibitor imidapril (20 mg x kg(-1) x day(-1)) for the subsequent 3 wk. After 4 wk, we observed significant arteriosclerosis of the coronary artery (medial thickening and fibrosis) and increased cardiac ACE activity in the 1wL + 3wNT group as well as in the 4wL-NAME group, but not in the 1wL + 3wACEI group. In a separate study, we examined apoptosis formation and found that posttreatment with imidapril (20 mg x kg(-1) x day(-1)) or an ANG II AT1-receptor antagonist, CS-866 (5 mg x kg(-1) x day(-1)), induced apoptosis (TdT-mediated nick end-labeling) in monocytes and myofibroblasts appearing in the inflammatory lesions associated with a clear degradation in the heart (DNA electrophoresis). In conclusion, treatment with the ACE inhibitor after 1 wk of L-NAME administration inhibited arteriosclerosis by inducing apoptosis in the cells with inflammatory lesions in this study, suggesting that increased ANG II activity inhibited apoptosis of the cells with inflammatory lesions and thus contributed to the development of arteriosclerosis.

Role of monocyte chemoattractant protein-1 in cardiovascular remodeling induced by chronic blockade of nitric oxide synthesis.

BACKGROUND: Chronic inhibition of endothelial nitric oxide (NO) synthesis by the administration of N:(omega)-nitro-L-arginine methyl ester (L-NAME) to rats induces early vascular inflammatory changes (monocyte infiltration into coronary vessels and monocyte chemoattractant protein-1 [MCP-1] expression) as well as subsequent arteriosclerosis (medial thickening and perivascular fibrosis) and cardiac fibrosis. However, the role of MCP-1 in this process is not known. METHODS AND RESULTS: We investigated the effect of a specific monoclonal anti-MCP-1 neutralizing antibody in rats treated with L-NAME to determine the role of monocytes in the regulation of cardiovascular remodeling. We found increased expression of MCP-1 mRNA in vascular endothelial cells and monocytes in inflammatory lesions. Cotreatment with an anti-MCP-1 antibody, but not with control IgG, prevented the L-NAME-induced early inflammation and reduced late coronary vascular medial thickening. In contrast, the anti-MCP-1 antibody did not decrease the development of perivascular fibrosis, the expression of transforming growth factor (TGF)-beta(1) mRNA, or systolic pressure overload induced by L-NAME administration. CONCLUSIONS: These results suggest that MCP-1 is necessary for the development of medial thickening as well as monocyte recruitment. In contrast, the pathogenesis of fibrosis may involve other factors, such as TGF-beta(1).

Anti-monocyte chemoattractant protein-1 gene therapy inhibits vascular remodeling in rats: blockade of MCP-1 activity after intramuscular transfer of a mutant gene inhibits vascular remodeling induced by chronic blockade of NO synthesis.

Monocyte chemoattractant protein-1 (MCP-1) may play an essential part in the formation of arteriosclerosis by recruiting monocytes into the arterial wall. Thus, we devised a new strategy for anti-MCP-1 gene therapy against arteriosclerosis by transfecting an amino-terminal deletion mutant (missing the amino-terminal amino acids 2 to 8) of the human MCP-1 gene into a remote organ (skeletal muscles). Intramuscular transduction with the mutant MCP-1 gene blocked monocyte recruitment induced by a subcutaneous injection of recombinant MCP-1. In a rat model in which the chronic inhibition of endothelial nitric oxide synthesis induces early vascular inflammation as well as subsequent coronary vascular remodeling, this strategy suppressed monocyte recruitment into the coronary vessels and the development of vascular medial thickening, but did not reduce perivascular fibrosis. Thus, MCP-1 is necessary for the development of medial thickening but not for fibrosis in this model. This new strategy may be a useful and feasible gene therapy against arteriosclerosis.

Increased activity of nuclear factor-kappaB participates in cardiovascular remodeling induced by chronic inhibition of nitric oxide synthesis in rats.

BACKGROUND: Chronic inhibition of endothelial nitric oxide (NO) synthesis by the administration of N(omega)-nitro-L-arginine methyl ester (L-NAME) to rats induces early vascular inflammatory changes [monocyte infiltration into coronary vessels, nuclear factor-kappaB (NF-kappaB) activation, and monocyte chemoattractant protein-1 expression] as well as subsequent arteriosclerosis (medial thickening and perivascular fibrosis) and cardiac fibrosis. However, no direct evidence for the importance of NF-kappaB in this process is known. METHODS AND RESULTS: We examined the effect of a cis element decoy strategy to address the functional importance of NF-kappaB in the pathogenesis of cardiovascular remodeling. We found here that in vivo transfection of cis element decoy oligodeoxynucleotides against NF-kappaB to hearts prevented the L-NAME-induced early inflammation and subsequent coronary vascular medial thickening. In contrast, NF-kappaB decoy oligodeoxynucleotide transfection did not decrease the development of fibrosis, the expression of transforming growth factor-beta(1) mRNA, or systolic pressure overload induced by L-NAME administration. CONCLUSIONS: The NF-kappaB system participates importantly in the development of early vascular inflammation and subsequent medial thickening but not in fibrogenesis in this model. The present study may provide a new aspect of how endothelium-derived NO contributes to anti-inflammatory and/or antiarteriosclerotic properties of the vascular endothelium in vivo.

Pravastatin attenuates cardiovascular inflammatory and proliferative changes in a rat model of chronic inhibition of nitric oxide synthesis by its cholesterol-lowering independent actions.

Recent studies suggest that some of the beneficial effects of 3-hydroxyl-3-methylglutaryl (HMG)-CoA reductase inhibitors such as pravastatin may be through their cholesterol-lowering independent effects on the blood vessels. We have recently reported that chronic inhibition of nitric oxide (NO) synthesis with N(omega)nitro-L-arginine methyl ester (L-NAME) increases systolic blood pressure and induces coronary vascular inflammatory changes in rats. We designed this study to investigate whether treatment with pravastatin attenuates such proarteriosclerotic changes through their cholesterol-lowering independent effects. Several groups of Wistar-Kyoto rats were studied: the control group, L group received L-NAME in their drinking water (100 mg/kg per day) and L+Px group received L-NAME plus pravastatin (50, 100 or 250 mg/kg per day). We observed marked increases in monocyte infiltration into the coronary arteries, proliferative cell nuclear antigen-positive cells, and monocyte chemoattractant protein-1 (MCP-1) expression in the heart on day 3 after L-NAME administration began. Treatment with pravastatin did not affect serum cholesterol levels or systolic blood pressure but did reduce the L-NAME induced inflammatory and proliferative changes. Pravastatin also attenuated the MCP-1 gene expression induced by L-NAME. In summary, pravastatin inhibited the inflammatory and proliferative changes in the coronary vessels through their cholesterol-independent effects in this model, which may provide an insight into the mechanisms of anti-inflammatory or anti-arteriosclerotic actions of pravastatin.

Role of transforming growth factor-beta1 in cardiovascular inflammatory changes induced by chronic inhibition of nitric oxide synthesis.

We previously reported that chronic inhibition of nitric oxide (NO) synthesis with N(omega)-nitro-L-arginine methyl ester (L-NAME) induces inflammatory changes (monocyte infiltration, myofibroblast formation, and monocyte chemoattractant protein-1 [MCP-1] and transforming growth factor-beta1 [TGF-beta1] expression) in the rat heart and vessel. There is debate regarding whether TGF-beta1 exhibits proinflammatory or anti-inflammatory activities. We used the rat model to investigate the role of TGF-beta in the pathogenesis of such inflammatory changes. We show here that infiltrating monocytes and myofibroblasts in the inflammatory lesions produced TGF-beta1 on the third day of L-NAME administration. Cotreatment with a monoclonal antibody against TGF-beta1, but not with control IgG, prevented the L-NAME-induced cardiac inflammation. The antibody also significantly inhibited the gene expression of MCP-1, P-selectin, and intercellular adhesion molecule-1. In summary, the antibody against TGF-beta1 prevented inflammatory changes in rat heart and vessel induced by chronic inhibition of NO synthesis, suggesting that increased production of TGF-beta1 is involved in the inflammatory changes in this model.

Important role of local angiotensin II activity mediated via type 1 receptor in the pathogenesis of cardiovascular inflammatory changes induced by chronic blockade of nitric oxide synthesis in rats.

BACKGROUND: The chronic inhibition of NO synthesis by N(omega)-nitro-L-arginine methyl ester (L-NAME) upregulates the cardiovascular tissue angiotensin II (Ang II)-generating system and induces cardiovascular inflammatory changes in rats. METHODS AND RESULTS: We used a rat model to investigate the role of local Ang II activity in the pathogenesis of such inflammatory changes. Marked increases in monocyte infiltration into coronary vessels and myocardial interstitial areas, monocyte chemoattractant protein-1 (MCP-1) expression, and nuclear factor-kappaB (NF-kappaB, an important redox-sensitive transcriptional factor that induces MCP-1) activity were observed on day 3 of L-NAME administration. Along with these changes, vascular superoxide anion production was also increased. Treatment with an Ang II type 1 receptor antagonist or with a thiol-containing antioxidant, N-acetylcysteine, prevented all of these changes. CONCLUSIONS: Increased Ang II activity mediated via the type 1 receptor may thus be important in the pathogenesis of early cardiovascular inflammatory changes in this model. Endothelium-derived NO may decrease MCP-1 production and oxidative stress-sensitive signals by suppressing localized activity of Ang II.

Chronic inhibition of nitric oxide synthesis in rats increases aortic superoxide anion production via the action of angiotensin II.

OBJECTIVE: Chronic inhibition of nitric oxide (NO) synthesis by Nomega-nitro-L-arginine methyl ester (L-NAME) increases vascular tissue angiotensin II activity and oxidative stress in animals by incompletely understood mechanisms. In a rat model, we investigated the role of local angiotensin II activity in the pathogenesis of increased oxidative stress. DESIGN: We studied the aortas of control rats and others receiving L-NAME or L-NAME plus an angiotensin II type 1 receptor antagonist (CS-866). RESULTS: Administration of L-NAME for 7 days significantly increased superoxide anion (O2-) and both immunoreactivity and electrophoretically demonstrable activity of redox-sensitive transcription factors (NF-kappaB and AP-1). Treatment with the angiotensin II type 1 receptor antagonist prevented all of the above changes. The observed effects of the type 1 receptor antagonist was independent of the L-NAME-induced arterial hypertension. CONCLUSIONS: These findings suggest that chronic inhibition of NO synthesis may increase vascular oxidative stress and oxidative stress-sensitive signals via the action of angiotensin II mediated via type 1 receptors.

Three-dimensional arrangement of muscle bundles in the outer layers of rodentia vasa deferentia.

Three-dimensional arrangement of the smooth muscle bundles of the outer layer of the vas deferens musculature in mammals (guinea-pigs, rats and mice) was examined under the scanning electron microscope (SEM) after removal of fibrous connective tissue elements. Muscle fibers of all examined animals formed bundles. In the guinea-pig, similar sized bundles extended longitudinally along the tubular vas deferens and branched to anastomose with branches of neighboring bundles to create a net which was regular in form. In the rat, longitudinal muscle bundles constituted an outer layer in the form of a net, which was roughly enmeshed with variously-sized, transverse or oblique bundles in anastomosis with underlying longitudinal bundles. In the mouse, longitudinal bundles of irregular thickness branched into many small bundles and anastomosed not only with neighboring bundles to create an irregular net. In both the rat and the mouse there were bundles extending over many other bundles to anastomose with them at a far point. Junctional structures were well developed between neighboring fibers. Myofibrils were represented as thin streaks on muscle fiber surfaces. Varicosed nerve fibers existed between muscle fibers and in narrow cytoplasmic grooves in all the examined animal species. The findings are discussed in correlation with electrophysiological data.

Pathogenic role of oxidative stress in vascular angiotensin-converting enzyme activation in long-term blockade of nitric oxide synthesis in rats.

Inhibition of nitric oxide (NO) synthesis with N(omega)-nitro-L-arginine methyl ester (L-NAME) activates vascular angiotensin-converting enzyme (ACE) and causes oxidative stress. We investigated the role of oxidative stress in the pathogenesis of ACE activation in rats. Studies involved aortas of rats receiving no treatment, L-NAME, L-NAME plus L-arginine, or L-NAME plus an antioxidant drug (N-acetylcysteine, allopurinol, or ebselen) for 7 days. L-NAME significantly increased oxidative stress (O(2)(-)) and ACE activity. The increased O(2)(-) production was normalized by removal of endothelium. Immunohistochemistry showed the increased ACE activity in the endothelial layer. Treatment with antioxidant drugs did not affect the L-NAME-induced increase in systolic arterial pressure but did prevent increases in vascular O(2)(-) production and ACE activity. These results implicate oxidative stress in the pathogenesis of vascular ACE activation in rats with long-term inhibition of NO synthesis. The observed effects of antioxidant drugs on ACE activation do not appear to involve the hypertension induced by L-NAME.

Extensive gene duplication in the early evolution of animals before the parazoan-eumetazoan split demonstrated by G proteins and protein tyrosine kinases from sponge and hydra.

To know whether genes involved in cell-cell communication typical of multicellular animals dramatically increased in concert with the Cambrian explosion, the rapid evolutionary burst in the major groups of animals, and whether these genes exist in the sponge lacking cell cohesiveness and coordination typical of eumetazoans, we have carried out cloning of the G-protein alpha subunit (Galpha) and the protein tyrosine kinase (PTK) cDNAs from Ephydatia fluviatilis (freshwater sponge) and Hydra magnipapillata strain 105 (hydra). We obtained 13 Galpha and 20 PTK cDNAs. Generally animal gene families diverged first by gene duplication (subtype duplication) that gave rise to diverse subtypes with different primary functions, followed by further gene duplication in the same subtype (isoform duplication) that gave rise to isoform genes with virtually identical function. Phylogenetic trees of Galpha and PTK families including cDNAs from sponge and hydra revealed that most of the present-day subtypes had been established in the very early evolution of animals before the parazoan-eumetazoan split, the earliest branching among the extant animal phyla, by extensive subtype duplication: for PTK and Galpha families, 23 and 9 subtype duplications were observed in the early stage before the parazoan-eumetazoan split, respectively, and after that split, only 2 and 1 subtype duplications were found, respectively. After the separation from arthropods, vertebrates underwent frequent isoform duplications before the fish-tetrapod split. Furthermore, rapid amino acid changes appear to have occurred in concert with the extensive subtype duplication and isoform duplication. Thus the pattern of gene diversification during animal evolution might be characterized by bursts of gene duplication interrupted by considerably long periods of silence, instead of proceeding gradually, and there might be no direct link between the Cambrian explosion and the extensive gene duplication that generated diverse functions (subtypes) of these families.