Development of hyperfibrinogenemia in spontaneously hypertensive and hyperlipidemic rats: a potentially useful animal model as a complication of hypertension and hyperlipidemia.

According to current concepts, hypertension and hyperlipidemia cause vascular damage that leads to a hypercoagulative state. In this study, we investigated whether spontaneously hypertensive and hyperlipidemic rats (SHHR) can be a useful experimental model for complications in combined hypertension and hyperlipidemia, by comparing coagulative and fibrinolytic activities in SHHR with those in spontaneously hypertensive rats (SHR) and spontaneously hyperlipidemic rats (HLR). We measured coagulation and fibrinolysis markers in plasma and levels of fibrinogen and prothrombin mRNA in livers of eight-month-old male Wistar Kyoto rats (WKY), Sprague-Dawley rats (SD), SHR, HLR and SHHR. The plasma levels of fibrinogen in SHR, HLR and SHHR were significantly higher than those in WKY and SD, and were highest in SHHR. Higher plasma levels of antithrombin III and plasminogen were detected in increasing order in SHR, HLR and SHHR as compared to those in WKY and SD. Hepatic mRNA expressions of fibrinogen chains and prothrombin were enhanced in SHR, HLR and SHHR, resulting in increased plasma fibrinogen levels in SHHR. These results suggest that hypertension and hyperlipidemia can each cause hypercoagulation, with hyperlipidemia being a stronger factor than hypertension. Since a greater hypercoagulative state is a complication of combined hypertension and hyperlipidemia, the SHHR model is a good system for studying the early stage of atherosclerosis ensuing from hyperfibrinogenemia.     

Phenotypes of IRS-2 deficient mice produced by reproductive technology are stable.

We studied the impact of "IVF - ET" on the glucose tolerance test (GTT), insulin tolerance test (ITT) and adiponectin to investigate differences in the phenotypes of B6J- Irs2(-/-) mice. The B6J-Irs2(-/-) mice (KO-Nat group) were prepared by natural mating. Other mice were produced by IVF-ET used ICR strain recipients and surrogate mothers (KO-IVF group). Measurement of body weight, GTT, ITT and blood sampling were performed at the ages of 6, 14 and 24 weeks after birth. Body weights, impaired glucose tolerance, insulin resistance and plasma adiponectin concentrations did not differ for each gender between the KO-IVF and KO-Nat groups. Therefore, we concluded that phenotypes of Irs2(-/-) mice produced by reproductive technology are stable.     

SNP analyses of growth factor genes EGF, TGFbeta-1, and HGF reveal haplotypic association of EGF with autism

Autism is a pervasive neurodevelopmental disorder diagnosed in early childhood. Growth factors have been found to play a key role in the cellular differentiation and proliferation of the central and peripheral nervous systems. Epidermal growth factor (EGF) is detected in several regions of the developing and adult brain, where, it enhances the differentiation, maturation, and survival of a variety of neurons. Transforming growth factor-beta (TGFbeta) isoforms play an important role in neuronal survival, and the hepatocyte growth factor (HGF) has been shown to exhibit neurotrophic activity. We examined the association of EGF, TGFbeta1, and HGF genes with autism, in a trio association study, using DNA samples from families recruited to the Autism Genetic Resource Exchange; 252 trios with a male offspring scored for autism were selected for the study. Transmission disequilibrium test revealed significant haplotypic association of EGF with autism. No significant SNP or haplotypic associations were observed for TGFbeta1 or HGF. Given the role of EGF in brain and neuronal development, we suggest a possible role of EGF in the pathogenesis of autism.     

Hypotensive activity of TCV-116, a newly developed angiotensin II receptor antagonist, in spontaneously hypertensive rats.

TCV-116, a recently developed angiotensin II (Ang II) receptor antagonist, was administered orally (1 mg/kg per day) to 10-week-old spontaneously hypertensive rats (SHR) for 2 weeks. Blood pressure and plasma components of the renin-angiotensin-aldosterone system were determined in these rats. TCV-116 produced a marked reduction in blood pressure without altering heart rate. Whereas plasma renin concentration (PRC), angiotensin I (Ang I) and angiotensin II (Ang II) all were significantly increased, plasma aldosterone was decreased by approximately 70% compared with control animals. These results not only indicate therapeutic efficacy of this agent in the chronic treatment of human hypertension, but support also the concept that the renin-angiotensin system plays an important role in the control of blood pressure in this animal model of human essential hypertension.     

Conjugal transfer of hydrogen-oxidizing ability of Alcaligenes hydrogenophilus to Pseudomonas oxalaticus

Conjugal transfer of hydrogen-oxidizing ability (Hox) of the hydrogen bacterium Alcaligenes hydrogenophilus was examined. Intraspecific cross of plasmid pHG21-a that encodes hydrogenases that mediate hydrogen oxidation was most frequent at 25 C; the optimal temperature for growth was 30 C. The plasmid could be transferred from A. hydrogenophilus to Pseudomonas oxalaticus OX1 and OX4, and the resulting strains gained the capacity for autotrophic growth with H2 and CO2. Plasmid pHG21-a was maintained in P. oxalaticus OX1 and OX4 as stably as in A. hydrogenophilus.     

Fetal Lung Cells Transfer Improves Emphysematous Change in a Mouse Model of Neutrophil Elastase-Induced Lung Emphysema

Recently, several studies for lung regeneration have been reported. However, regenerating the lung tissue by the transfer of any cells directly to the lung has been hardly successful. The aim of this study was to evaluate the effect of fetal lung cells (FLCs) in a mouse model of lung emphysema. C57BL/6 mice were stimulated with neutrophil elastase (NE) intra-tracheally (i.t.) to generate lung emphysema. To collect fetal lung cells, C57BL/6-Tg (CAG-EGFP) mice were bred for 14 days. Before delivery, the bred mice were euthanized, and fetal lungs were harvested from the fetal mice and the cells were collected. The FLCs were transferred i.t. 24 h after the NE instillation. Four weeks after the NE instillation, mice were euthanized, and the samples were collected. The mean linear intercept (MLI) was significantly prolonged in the NE instillation group compared to the control group. However, in the FLCs transfer group stimulated with NE, the MLI became shorter than the NE-stimulated group without an FLCs transfer. This result shows that an FLCs transfer inhibited the progression of lung emphysema. Additionally, motility of the mice was also improved by the FLCs transfer. These results indicate that transfer of the FLCs, which were presumed to be progenitor cells for lung tissue, may improve the emphysematous change.     

Expression of transfected human Na+/H+ exchanger (NHE-1) in the basolateral membrane of opossum kidney cells

Some epithelial cells have Na⁺/H⁺ exchanger (NHE) activity in both apical and basolateral membranes. Amiloride-sensitive NHE-1 is generally identified in the basolateral membrane. The renal cell line, OK7a, targets amiloride-resistant NHE predominantly to the apical membrane. It is controversial whether the transfected NHE-1 is targeted preferentially to the basolateral membrane in OK7a cells, when human NHE-1 is chronically expressed under control of constitutively active promoters. We tried to identify the membranes in which the transfected human NHE-1 could be detected following acute expression in OK7a cells. We have always observed small Na⁺-dependent pH recovery in the basolateral membrane in OK7a cells. It is, however, controversial whether or not OK7a cells express NHE activity in the basolateral membrane. We also characterized Na⁺-dependent pH recovery in the basolateral membrane. It was not inhibited by [4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid] (DIDS), [4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid] (SITS), or contralateral amiloride. Li⁺ but not K⁺, chol⁺, or NMG⁺ could replace Na⁺. These results are consistent with the presence of the NHE in the basolateral membrane. NHE activities were predominant in the apical membrane and those in both membranes were resistant to amiloride analogs. After stable transfection with human NHE-1 in a vector utilizing the metallothionein promoter, overnight induction with Zn²⁺ increased the NHE activity and its sensitivity to amiloride only in the basolateral membrane in OK7a cells. We conclude that the transfected human NHE-1 is exclusively targeted to the basolateral membrane of OK7a cells during acute induction. J Cell Physiol 178:44–50, 1999. © 1999 Wiley-Liss, Inc.     

The hupC gene product is a component of the electron transport system for hydrogen oxidation in Pseudomonas hydrogenovora

The hydrogenase gene cluster containing nine genes (hupSLCDFGHIJ) was identified by sequencing of an 8.8-kb DNA region from Pseudomonas hydrogenovora. To investigate the function of the hupC gene product, we isolated a hupC-null mutant (HID3) of P. hydrogenovora by introducing an in-frame deletion into the hupC. The mutant, HID3, could not grow autotrophically but retained half the level of hydrogenase activity of the wild-type strain. Results of the oxygen consumption test and Western blot analysis revealed that the hupC gene product is a b-type cytochrome but not involved in the hydrogenase maturation process.