Involvement of endothelin-1 in habitual exercise-induced increase in arterial compliance

AIM

Habitual aerobic exercise results in a significant increase in central arterial compliance. Endothelin-1 (ET-1) is a potent endothelium-derived vasoconstrictor peptide and could play a role in mediating the habitual aerobic exercise-induced increase in central arterial compliance. The aim of the present study was to examine whether ET-1 is involved in the mechanisms underlying the increase in central arterial compliance with aerobic exercise training.

METHODS

Seven apparently healthy middle-aged and older (60 +/- 3 years) adults underwent systemic endothelin-A/B (ET(A/B))-receptor blockade (500 mg of Tracleer) before and after 12 weeks of aerobic exercise training (70 +/- 1% of maximal heart rate, 44 +/- 2 min day(-1), 4.4 +/- 0.1 days week(-1)).

RESULTS

Basal carotid arterial compliance (via simultaneous B-mode ultrasound and arterial applanation tonometry on the common carotid artery) increased significantly after exercise training. Resting plasma ET-1 concentration decreased significantly after exercise training. Before exercise intervention, carotid arterial compliance increased significantly with the administration of the ET(A/B)-receptor blockade. After training, however, increases in carotid arterial compliance previously observed with the ET(A/B)-receptor blockade before training were abolished.

CONCLUSIONS

Regular aerobic exercise training enhances central arterial compliance in middle-aged and older humans. The increase in arterial compliance was associated with the corresponding reduction in plasma ET-1 concentration as well as the elimination of ET-1-mediated vascular tone. These results suggest that reductions in ET-1 may be an important mechanism underlying the beneficial effect of exercise training on central artery compliance.

Colorectal resection by a minilaparotomy approach vs. conventional operation for colon cancer. Results of a prospective randomized trial

BACKGROUND/AIMS

The aim of this study was to evaluate the outcome of patients undergoing colorectal resection for colon cancer using a minilaparotomy approach or conventional surgical procedure.

METHODOLOGY

In a prospective randomized trial, twenty consecutive patients undergoing colon resection by minilaparotomy and 26 patients undergoing conventional open colorectal resection were evaluated. Immunologic, metabolic and hemodynamic studies were performed in all patients. Cell surface markers were used to characterize Th1/2 balance, using flow cytometry. Indirect calorimetry to measure energy expenditure, and pulse dye densitometry for a hemodynamic study were performed in patients until 14 POD.

RESULTS

The lengths of laparotomy incisions were 7.5+/-1.5 cm and 20.5+/-2.5 cm in the minilaparotomy and conventional group, respectively. Mean operative time, morbidity and postoperative hospital stay of the two groups was not significantly different. However, mean operative blood loss, days to p.o. liquids and walking, and amount of analgesic usage were significantly less in the minilaparotomy group. The postoperative ratio of Th1/2 in CD4+T cells was decreased in both groups, but no significant difference was seen between the groups. Significant increase of resting energy expenditure and cardiac index was seen until day 3 in the conventional group, whereas those values increased until day 1 in the minilaparotomy group.

CONCLUSIONS

Compared with conventional colorectal resection for colon cancer, colorectal resection by minilaparotomy results in a more rapid return of bowel function, less pain and host response. However, the alternations of the host response for surgical stress between the two groups are similar in the early postoperative stage (days 1-2).

[Anaphylactic shock related to aprotinin induced by anti-aprotinin immunoglobulin G antibody alone; report of a case]

Anaphylactic shock related to aprotinin has been reported to be induced exclusively in the presence of IgE antibody. And the possibility of anaphylactic shock induced by anti-aprotinin IgG antibody alone was controversial. In this paper, we describe the first case of anaphylactic shock induced by aprotinin-specific IgG antibody alone. A 55-year-old man underwent surgical repair of the descending aorta with the use of aprotinin at 2 months after first aprotinin usage. Immediately after initiation of cardiopulmonary bypass with the continuous infusion of aprotinin, clinical symptoms of anaphylactic reaction were found. Postoperative drug lymphocyte stimulation test for aprotinin and aprotinin-specific IgE antibody were negative, but aprotinin-specific IgG antibody was 163 mg/l and positive.

Brain site-specific gene expression analysis in Alzheimer's disease patients

BACKGROUND

Alzheimer's disease (AD) is an age-related neurodegenerative disorder that is characterized by a progressive loss of higher cognitive functions. The brain of an individual with AD exhibits extracellular senile plaques (SPs) of aggregated amyloid-beta peptide (Abeta) and intracellular neurofibrillary tangles (NFTs). Given the critical role of neuronal transport of both proteins and organelles, it is not surprising that perturbation of microtubule-based transport may play a major role in the pathogenesis of AD.

MATERIALS AND METHODS

We used the cDNA subtraction methodology and in vitro neural cell culture analyses to study the meaning of the brain site-specific gene expression pattern in cerebral tissue obtained from AD patients and also from control subjects at autopsy.

RESULTS

We observed that cytoskeleton-associated proteins were down-regulated in AD subjects. We also noted an altered expression of the microtubule-associated protein 1B (MAP1B), the heat-shock protein (HSP)-90 (a key chaperone molecule), the tripartite motif-containing proteins (TRIM)-32/37 (an anti apoptotic enzyme with ubiquitin-protein ligase activity) and the Reticulon-3 (a modulator of the amyloid-precursor-protein (APP) cleavage) in AD brains. Additional molecular- and cell-biological studies revealed that small interfering RNA (siRNA)-mediated down-regulation of MAP1B expression leads to neuronal cell death in vitro.

CONCLUSION

Altered expression of MAP1B, HSP90, TRIM32/37 and Reticulon-3 provides new clues by which the ubiquitin-proteasome-, the protein-chaperon- and the APP-processing systems are disturbed in AD, thus, leading to neuritic amyloid plaques and neurofibrillary tangles.

Postoperative host responses in elderly patients after gastrointestinal surgery

BACKGROUND/AIMS

The age-associated dysregulation of hemodynamic, metabolic and immune responses contributes to the high incidence of complications after major abdominal surgery.

METHODOLOGY

Ninety-five patients who underwent gastric resection (n=51) and colorectal resection (n=44) were divided according to age into Groups A (n=45, less than 70 years old), B (n=30, 70-79 years) and C (n=20, over 80 years). Flow cytometric analysis of CD4+ lymphocytes for interferon (IFN)-gamma and interleukin (IL)-4 production determined the Th1/2 balance. Energy expenditure was measured by indirect calorimetry, and hemodynamics were studied using pulse dye densitometry.

RESULTS

Surgical procedures, operating time, blood loss and morbidity did not significantly differ among the three groups. The cardiac index (CI) in group A and B increased significantly over preoperative levels until POD 3, but there were no significant perioperative changes in the CI levels of group C. Resting energy expenditure levels changed similarly to those of CI. The postoperative Th1/2 ratio decreased from young to elderly to very elderly patients, although no differences were significant before surgery. The postoperative percentage of CD4+IFN-gamma +T cells (Th1) in group C decreased significantly despite of no significant changes in that of group A and B. In contrast, the ratio of CD4+IL-4+T cells (Th2) in the all groups significantly increased after surgery.

CONCLUSIONS

Host responses in elderly patients after major abdominal surgery were more hyperdynamic and hypermetabolic than those of young patients. Postoperative dysregulation of the Th1/2 balance was also associated with aging. However, host responses appear to significantly differ between elderly and very elderly patients.

Contribution of systemic arterial compliance and systemic vascular resistance to effective arterial elastance changes during exercise in humans

BACKGROUND

Effective arterial elastance (Ea), an index of arterial load, increases with elevations in left ventricular elastance to maximize the efficiency of left ventricular stroke work during exercise. Systemic arterial compliance (C) and vascular resistance (R) are the primary components contributing to Ea, and R plays a greater role in determining Ea at rest. We hypothesized that the contribution of C to Ea increases during exercise to maintain an optimal balance between arterial load and ventricular elastance, and that the increase in Ea is due primarily to a reduction in C.

AIM

The aim of this study was to investigate the contributions of C and R to Ea during exercise.

METHODS

Ea (0.9 x systolic blood pressure/stroke volume), C (stroke volume/pulse pressure), R (mean blood pressure/cardiac output), and cardiac cycle length (T) were measured at rest and during exercise of 40%, 60% and 80% maximal oxygen uptake (O(2max)) using Doppler echocardiography in 45 healthy men.

RESULTS

Ea did not differ between rest and 40%O(2max), but it was greater at 60% and 80%O(2max). C markedly decreased during exercise in an exercise intensity-dependent manner. The changes in R/T during exercise were small, whereas it decreased at 40%O(2max) and gradually increased at 60% and 80%O(2max).

CONCLUSIONS

The present results suggest that the contribution of systemic arterial compliance to effective arterial elastance increases during exercise. Therefore, we propose that the increase in arterial load during exercise is mainly driven by a reduction in systemic arterial compliance.

Costs and benefits of laparoscopic cholecystectomy: abdominal wall lifting vs. pneumoperitoneum procedure

BACKGROUND/AIMS

Gasless laparoscopic surgery using the abdominal wall lifting (AWL) method was first developed in Japan and has been used in various surgical fields. The AWL method allows the use of conventional reusable surgical instruments. The purpose of this study was to compare the cost-effectiveness of laparoscopic cholecystectomy (LSC) using the AWL method in relation to that using pneumoperitoneum (P) method.

METHODOLOGY

Retrospective analysis of 431 LSC procedures between 1991 and 2004 was performed. The two surgical groups consisted of consecutively operated patients with a diagnosis of cholecystolithiasis or gallbladder polyps. One group consisted of 224 LSC procedures performed using the P method from 1992 to 1998 and the other group comprised 207 LSC performed using the AWL method from 1998 to 2004. All instruments used in the P method were disposable, whereas trocars, scissors, dissectors, graspers and L-hook electrodes (excluding clips) used in the AWL method were reusable. Hospital expenses, length of hospital admission and complication rates were analyzed.

RESULTS

Mean hospital cost per case for LSC using the AWL method (dollars 6743) was 7% less expensive than that using the P method (dolars 7215). Costs of operative equipment contributed to the difference (mean dollars 912 per case) in total cost. Conversion to open cholecystectomy occurred in 6 cases (2.9%) using the AWL method and 7 cases (3.1%) using the P method. There were no significant differences in length of hospital admission or complication rates between the two groups.

CONCLUSIONS

LSC using AWL method was less expensive than that using P method. This is mainly due to the use of reusable instruments in the AWL method. If LSC is performed using the AWL method instead of using disposable equipment, considerable savings can be achieved without compromising patient safety.

Mice with neuron-specific accumulation of mitochondrial DNA mutations show mood disorder-like phenotypes

There is no established genetic model of bipolar disorder or major depression, which hampers research of these mood disorders. Although mood disorders are multifactorial diseases, they are sometimes manifested by one of pleiotropic effects of a single major gene defect. We focused on chronic progressive external ophthalmoplegia (CPEO), patients with which sometimes have comorbid mood disorders. Chronic progressive external ophthalmoplegia is a mitochondrial disease, which is accompanied by accumulation of mitochondrial DNA (mtDNA) deletions caused by mutations in nuclear-encoded genes such as POLG (mtDNA polymerase). We generated transgenic mice, in which mutant POLG was expressed in a neuron-specific manner. The mice showed forebrain-specific defects of mtDNA and had altered monoaminergic functions in the brain. The mutant mice exhibited characteristic behavioral phenotypes, a distorted day-night rhythm and a robust periodic activity pattern associated with estrous cycle. These abnormal behaviors resembling mood disorder were worsened by tricyclic antidepressant treatment and improved by lithium, a mood stabilizer. We also observed antidepressant-induced mania-like behavior and long-lasting irregularity of activity in some mutant animals. Our data suggest that accumulation of mtDNA defects in brain caused mood disorder-like mental symptoms with similar treatment responses to bipolar disorder. These findings are compatible with mitochondrial dysfunction hypothesis of bipolar disorder.

Postoperative metabolic and circulatory responses in patients that express SIRS after major digestive surgery

BACKGROUND/AIMS

Systemic inflammatory response syndrome (SIRS) includes a number of pathologic states because of its loose definition. This study assessed differences in metabolic and circulatory host responses in various patients with SIRS perioperatively.

METHODOLOGY

Fifty-four patients who underwent abdominal surgeries [gastric resection (n=20), colorectal resection (n=24), hepatic resection (n=8)] were divided into two groups: Group A; SIRS (+) on 1 postoperative day (POD), (n=29), B; SIRS (-) on 1 POD, (n=25). The other eight non-operated patients with SIRS caused by infection were enrolled in Group C, as common SIRS. Indirect calorimetry, body impedance measurement to assess water compartments and pulse dye-densitometry for hemodynamic examination were performed in subjects until 14 POD.

RESULTS

The ratio of energy expenditure to basal energy expenditure (%REE) was significantly increased postoperatively, and there were significant differences on %REE from 3 POD to 14 POD between groups A and B. However, %REE in group C was 162+/-23%, which was significantly increased compared with that at 1 POD of groups A (130 +/- 17%) and B (125+/-18%). Cardiac output in group A showed a significant increase until 3 POD compared with that in group B but was significantly lower than that in group C.

CONCLUSIONS

Subjects with common SIRS caused by infection were significantly more hypermetabolic than subjects with postoperative SIRS. Adequate energy intake and circulatory management should be cautiously determined according to the severity of SIRS.

Malignant fibrous histiocytoma of the spleen: report of a case and literature review

There is a marked paucity of reports on malignant fibrous histiocytoma (MFH) of the spleen in the literature, and there are no previous reports of its color Doppler sonographic (US) and contrast-enhanced US findings. We report on an 82-year-old male with splenic MFH (inflammatory subtype), with an emphasis on color Doppler and contrast-enhanced US findings.

The penis: a new target and source of estrogen in male reproduction

In the past decade, interest and knowledge in the role of estrogen in male reproduction and fertility has gained significant momentum. More recently, the cellular distribution and activity of estrogen receptors (alpha and beta)(ER) and aromatase (estrogen synthesis) has been reported in the penis, making the penis the latest "frontier" in the study of estrogen in male reproduction. ER and aromatase are broadly and abundantly expressed in various penile compartments and cell types (erectile tissues, urethral epithelia, vascular and neuronal cells), suggesting the complexity and significance of the estrogen-ER system in penile events. Unraveling this complexity is important and will require utilization of the various resources that are now at our disposal including, animal models and human lacking or deficient in ER and aromatase and the use of advanced and sensitive techniques. Some of the obvious areas that require our attention include: 1) a comprehensive mapping of ER-alpha and -beta cellular expression in the different penile compartments and subpopulations of cells, 2) delineation of the specific roles of estrogen in the different subpopulations of cells, 3) establishing the relationship of the estrogen-ER system with the androgen-androgen receptor system, if any, and 4) characterizing the specific penile phenotypes in human and animals lacking or deficient in estrogen and ER. Some data generated thus far, although preliminary, appear to challenge the long held dogma that, overall, androgens have a regulatory monopoly of penile development and function.

Gene expression profiling of exercise-induced cardiac hypertrophy in rats

AIMS

Exercise training causes physiological cardiac hypertrophy, which acts to enhance cardiac function during exercise. However, the underlying molecular mechanisms are unclear. We investigated gene expression profile of exercise training-induced cardiac hypertrophy using left ventricle (LV) excised from exercise-trained and sedentary control rats (12-week old).

METHOD

Rats in the training group exercised on a treadmill for 8-week.

RESULTS

Left ventricular mass index and wall thickness in the exercise-trained group were significantly greater than that in the control group, indicating that the trained rats developed cardiac hypertrophy. Of the 3800 genes analysed in the microarray analyses, a total of 75 relevant genes (upregulation of 33 genes and downregulation of 42 genes) displayed alterations with exercise training. Among these genes, we focused on glycogen synthase kinase (GSK)-3beta, calcineurin-inhibitor (Cain), and endothelin (ET)-1 for their implicated roles in pathological cardiac hypertrophy, and confirmed the results of microarray analysis at mRNA and protein/peptide levels using quantitative PCR, Western blot, and EIA analyses. The gene expression of GSK-3beta decreased significantly and those of Cain and ET-1 increased significantly with exercise training. Furthermore, LV mass index was significantly correlated with GSK-3beta protein activity (r = -0.70, P < 0.01) and tissue ET-1 concentration (r = 0.52, P < 0.05). There were no changes in gene expressions in brain natriuretic peptide (BNP), angiotensin-correcting enzyme (ACE), interleukin-6, and vascular cell adhesion molecule (VCAM)-1.

CONCLUSION

These findings suggest that physiological and pathological LV hypertrophy may share some of the same molecular mechanisms in inducing LV hypertrophy (e.g. GSK-3beta, Cain, and ET-1) and that other genes (e.g. BNP, ACE) may differentiate physiological from pathological LV hypertrophy.

Malignant paraganglioma draining into the main portal vein

Abdominal paraganglioma is a relatively rare tumor, and there have been no previous reports describing its contrast-enhanced ultrasonographic findings. We report a case of a lesion of unknown origin incidentally detected by ultrasound in the right upper abdomen. The lesion was markedly hypervascular and contrast-enhanced ultrasonogram showed it to be communicating with the portal vein. This communication was then confirmed by angiogram. Such an arteriovenous communication through paraganglioma has been recently reported, and a diagnosis of a paraganglioma should be considered when contrast-enhanced ultrasonogram shows a solid mass of unknown origin draining directly into the venous system.

[Arch first technique using handmade branched graft]

We created a method using handmade branched graft to do the aortic arch surgery easier and safer. We made the branched graft using 12 and 8 mm vascular graft. A 77-year-old man with Stanford type A aortic dissection was operated with this method under deep hypothermia. After aortic root manipulation, perfusion of the aortic arch was stopped and selective cerebral perfusion was established. Left subclavian artery (LSCA) was anastomosed to one of the branches. The perfusion of the LSCA was re-started via one of its branches. Respectively, left common carotid artery and brachiocephalic artery reconstruction and reperfusion were performed in a same fashion. After distal anastomosis, anastomosis between the branched graft and main graft was performed consecutively. Postoperative course was uneventful and there was no complication. The treatment of our branched graft was easier than that of ready-made 4-branched graft. We could perform the operation under clear view for its movability with minimal cerebral ischemic time.

Prognosis of HTLV-I-positive renal transplant recipients

HTLV-I is the pathogen that causes adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy (HAM). The rate of disease development is low and the latency time is a few decades. However, the possible influence of immunosuppression on this disease development is unclear. The purpose of this study was to investigate the risk of development of ATL and HAM among the large number of HTLV-I-positive renal transplant recipients in western Japan. In principle immunosuppressive drugs have the possibilities to accelerate ATL development but are thought to suppress HAM development. Of 120 renal transplant recipients, 10 HTLV-I-positive recipients were reviewed, none of whom developed ATL or HAM. There are 11,896 dialysis patients in Japan and 300 dialysis patients in Okinawa who are registered with the JOTN for cadaveric renal transplant. The numbers of HTLV-I-positive patients in these groups were 97 (0.82%) and 26 (8.67%), respectively. These numbers are thought to be sufficient for an HTLV-I-positive recipient pool for HTLV-I-positive donors. Ten cases of ATL development and two of HAM development have been previously reported. Because of low number of ATL development, renal transplantation does not appear to be a contraindication for HTLV-I-positive chronic renal failure patients. In other words, kidneys from HTLV-I carriers, which include cadaveric donors, could be used for HTLV-I-positive recipients.

Acute exercise causes an enhancement of tissue renin-angiotensin system in the kidney in rats

AIMS

Initially, the renin-angiotensin system (RAS) produced through the classical endocrine pathway was well known for its regulation of blood pressure. However, it was revealed that a local autocrine and/or paracrine RAS may exist in a number of tissues (such as kidney). Exercise causes a redistribution of tissue blood flow, by which the blood flow is greatly increased in active muscles, whereas it is decreased in the splanchnic circulation (such as in the kidney). We hypothesized that exercise causes an enhancement of tissue RAS in the kidney.

METHODS

We studied whether exercise affects expression of angiotensinogen and angiotensin-converting enzyme (ACE) and tissue angiotensin II level in the kidney. The rats performed treadmill running for 30-min. Immediately after this exercise, kidney was quickly removed. Control rats remained at rest during this 30-min period.

RESULTS

The expression of angiotensinogen mRNA in the kidney was markedly higher in the exercise rats than in the control rats. ACE mRNA in the kidney was significantly higher in the exercise rats than in the control rats. Western blot analysis confirmed significant upregulation of ACE protein in the kidney after exercise. Tissue angiotensin II level was also increased by exercise.

CONCLUSION

The present study suggests that the exercise-induced enhancement of tissue RAS in the kidney causes vasoconstriction and hence decreases blood flow in the kidney, which are helpful in increasing blood flow in active muscles, thereby contributing to the redistribution of blood flow during exercise.

Successful treatment of a ruptured infected aneurysm of the lumbar artery with transcatheter embolization

We report a patient who had an infected aneurysm of the lumbar artery caused by prolonged psoas abscess-forming spondylitis due to methicillin-resistant Staphylococcus aureus and who was treated successfully with transcatheter arterial embolization. This case suggests that an infected aneurysm can be treated successfully by transcatheter arterial embolization in emergent situations (active bleeding or septicemia) even if surgery is contraindicated.

Hepatic resection leads to predominance of the T helper-2 lymphocyte phenotype

Recent studies have shown that the type 1/2 T helper (Th1/2) cell balance is shifted toward a Th2-type immune response not only by malignancy but also by surgical stress. This study evaluates in immune responses to surgical stress from liver surgery in comparison with other major abdominal surgeries. PATIENTS AND METHODS:: Eighty-five patients who underwent abdominal surgeries were divided into three groups: hepatic resection (n = 17), gastric resection (n = 38), and colorectal resection (n = 30). Blood sampling was performed before surgery, and on postoperative days (POD) 2 and 14. Cell surface markers were used to characterize Th1/2 balance by flow cytometry and a ratio of the percent IFN-gamma-producing (Th1) cells to IL-4-producing (Th2) cells were expressed as the Th1/2 balance. RESULTS:: The postoperative ratio of Th1 to Th2 was decreased significantly in all subjects to 4.5 +/- 3.0 on POD 2 from 6.7 +/- 4.2. The ratio of Th1 to Th2 in patients who underwent hepatic resection markedly decreased to 2.8 +/- 1.6 on POD 2, significantly different from those in patients undergoing gastric resection or colorectal resection. However, on POD 14 there were no longer any significant differences among the three surgical groups. CONCLUSIONS:: This study shows that hepatic resection induces a more marked shift of the Th1/2 balance toward Th2 than other major abdominal surgeries.

Hepatic resection induces a shift in the Th 1/2 balance toward Th 2 and produces hypermetabolic and hyperhemodynamic states

BACKGROUND/AIMS

Recent studies have shown that the type 1/2 T-helper (Th 1/2) cell balance is shifted toward a Th 2-type immune response not only by malignancy but also by surgical stress. The present study evaluated surgical stress as a result of liver surgery in comparison with that of other major abdominal surgeries. Immune, metabolic and circulatory responses to surgery were measured for determination of surgical stress.

METHODOLOGY

Eighty-five patients who underwent abdominal surgeries were divided into three groups: hepatic resection (n=17), gastric resection (n=38), colorectal resection (n= 30). Blood sampling was performed before surgery, and on postoperative days (POD) 2 and 14. The Th 1/2 helper T cell balance was determined by flow cytometric analysis of interferon-gamma and interleukin-4 expression. Energy expenditure was measured by indirect calorimetry, and hemodynamics was studied using pulse dye densitometry until POD 14.

RESULTS

Following surgery Th 1/2 ratios decreased significantly. Additionally, the Th 1/2 balance in patients with hepatic resection on POD 2 was significantly lower than that of patients with other major surgeries. However, on POD 14 there were no significant differences among the three groups. Resting energy expenditure and cardiac index on postoperative days 1 and 3 in patients with hepatic resection increased significantly above levels in the other surgical groups. Conversely, blood volume in the hepatic resection patients was significantly lower than that of other patients until POD 3. Ten patients who developed postoperative complications had significantly lower Th 1/2 ratios and more hypermetabolism.

CONCLUSIONS

This study reveals that hepatic resection induces a more marked shift toward a Th 2 helper T cell response and significantly more hypermetabolism than other major surgeries. A distinct pattern of Th 1/2 ratio changes during the early phase of the postoperative course in hepatic resection may be related to changes in metabolism and circulation. Therefore, determination of Th 1/2 balance may be of help in evaluating different surgical procedures, and management of energy intake and circulatory management may be cautiously determined based on the shift in Th 1/2 balance.

Basigin (CD147): a multifunctional transmembrane protein involved in reproduction, neural function, inflammation and tumor invasion

Basigin (Bsg) is a transmembrane glycoprotein with two immunoglobulin-like domains, and forms a family with embigin and neuroplastin. In these proteins a conserved glutamic acid is present in the middle for the transmembrane domain. Bsg is also called CD147 and EMMPRIN, and the symbol for the human basigin gene is BSG. BSG is located in chromosome 19 band p13. 3. Knockout mice deficient in the Bsg gene are sterile and show various neurological abnormalities. Bsg-deficient embryos are also difficult to implant. Bsg has been found to participate in the cell-surface orientation of monocarboxylic acid transporters (MCTs) to the plasma membrane. Dysfunction of the retina in Bsg-deficient mice is ascribed to the failure of plasma membrane integration of MCTs in the tissue. Bsg is also involved in inflammatory processes and is proposed to be a receptor of cyclophilin A; it is also likely to participate in HIV infection. Bsg in tumor cells triggers the production or release of matrix metalloproteinases in the surrounding mesenchymal cells and tumor cells, thereby contributing to tumor invasion. Furthermore, the association of Bsg with integrins might be important in signaling through Bsg.

Exercise training improves ageing-induced decrease in eNOS expression of the aorta

AIMS

Ageing impairs endothelial function such as the regulation of vascular tone. The release of nitric oxide (NO), which has a potent vasodilator effect and antiatherosclerotic property, is decreased in the aorta of aged rats. Exercise training, however, has been reported to increase the expression of endothelial NO synthase (eNOS) in the aorta of young rats. In aged rats, it is not known whether the expression of eNOS is altered by exercise training. We hypothesized that exercise training would improve the ageing-induced decrease in eNOS expression in vessels, and examined the messenger RNA (mRNA) and protein expression of eNOS in the aorta of sedentary-young rats (sedentary-young group; 4 months old), sedentary-aged rats (sedentary-aged group; 23 months old), and swim-trained aged rats (training-aged group; 23 months old, swimming training for 8 weeks, 5 days week(-1), 90 min day(-1)).

RESULTS

Body weight was significantly lower, and citrate synthase activity in the epitrochlearis muscle was significantly higher in the training-aged group compared with the sedentary-aged group. The mRNA expression of eNOS in the aorta was significantly higher in the training-aged group than in the sedentary-aged group, while it was significantly lower in both the sedentary-aged and training-aged groups than in the sedentary-young group. The expression of eNOS protein in the aorta was also significantly higher in the training-aged group than in the sedentary-aged group, while it was also significantly lower in the sedentary-aged group, but not in the training-aged group, than in the sedentary-young group.

CONCLUSION

The present results revealed that the production of eNOS in the aorta decreases with ageing, and that the decreased production is increased by exercise training in aged rats, which may produce beneficial effects on the impaired cardiovascular system caused by ageing.