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Akihiro Morikawa

Publications and source records attributed to Akihiro Morikawa.

At least 19 recordsLinked to original sources
PubMed2006

Study of nasopharyngeal bacterial flora. Second report. Variations in nasopharyngeal bacterial flora in children aged 6 years or younger when administered antimicrobial agents. Part 1.

In our first report, we investigated nasopharyngeal bacterial flora related to penicillin-resistant Streptococcus pneumoniae (PRSP) and beta-lactamase-negative ampicillin-resistant Haemophilus influenzae (BLNAR) and their relation to acute upper respiratory tract infection (AURTI). This report analyzes the results of a study of nasopharyngeal bacterial flora before the administration of antimicrobial agents in 172 AURTI patients aged 6 years or younger. In addition to Gram staining, microscopic observation, and culturing, a polymerase chain reaction (PCR) method was used to identify PRSP (gPRSP) and BLNAR (gBLNAR) drug-resistant genes. Of the patients analyzed, 90% had acute otitis media (AOM) and were aged 2 years or younger. The antimicrobial agents administered were amoxicillin (34%), clavulanic acid/amoxicillin (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). This was particularly true for patients administered CDTR-PI, among whom there were many who had already suffered one or more episodes of AOM by the age of 1 year or younger, and many in which gPRSP were detected (P < 0.01). There was a significant relation between the degree of nasopharyngeal inflammation indicated by leukocyte infiltration images and the amount of S. pneumoniae and H. influenzae detected, which are the main pathogenic bacteria causing AOM (P < 0.01). In addition to leukocyte infiltration images, there were cases in which shedding of ciliated cells was observed and/or giant monocytic cells. Both nasopharyngeal leukocyte infiltration images and/or shed cell findings observed in infant AURTI cases are important indices for the prompt detection of gPRSP and/or gBLNAR and appropriate doses of antimicrobial agents.

Age Factors↗
PubMed2006

Study of nasopharyngeal bacterial flora. Second report. Variations in nasopharyngeal bacterial flora in children aged 6 years or younger when administered antimicrobial agents. Part 2.

This report focuses on changes in the nasopharyngeal bacterial flora before and after administration of antimicrobial agents in 172 cases of acute upper respiratory infection in patients aged 6 years or younger. The antimicrobial agents administered were amoxicillin (AMPC) (34%), clavulanic acid/amoxicillin compound (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). Changes in nasopharyngeal bacterial flora were investigated with reexaminations conducted after 2-5 days (day 2-5 subgroup), 6-10 days (day 6-10 subgroup), and 11 days and thereafter. There was a significant reduction in the Streptococcus pneumoniae detected in the group administered AMPC (AMPC group) in the day 2-5 subgroup and the day 6-10 subgroup. There was also a significant decrease in H. influenzae in the group administered CDTR-PI (CDTR-PI group) in the day 2-5 subgroup. From this it was inferred that for the most part significant changes in infectious nasopharyngeal bacteria occurred in the day 2-5 subgroups. However, a significant improvement in the degree of inflammation, as indicated by leukocyte infiltration images for the AMPC group, was observed in the day 2-5 subgroup, and for the CDTR-PI group in the day 6-10 subgroup. On the other hand, in both the antimicrobial agent groups, S. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were newly detected at reexamination. Furthermore, a difference in the incidence of these bacteria was observed between the 2 antimicrobial agent groups. It was suggested that such phenomena related to the survival of resistant strains or a recurrence otitis media.

Anti-Infective Agents↗
PubMed2006

Effect of inhaled histamine on airway epithelial cell swelling in ozone-exposed Guinea pigs.

BACKGROUND: It has been reported that histamine stimulates ion channels on airway epithelial cells and induces changes in osmolarity and the ion composition of the periciliary field of airway epithelia. OBJECTIVE: To investigate the effect of inhaled histamine on epithelial cell swelling, we studied the role of airway epithelial cells under histamine inhalation challenge in an animal model of airway inflammation using ozone exposure. METHOD: After exposure to 3.0 ppm ozone for 2 h, guinea pigs were anesthetized and tracheostomized, and then, lung resistance (R(L)) was measured. Histamine inhalation challenge and histological examination were performed. RESULT: The values of R(L) before histamine inhalation in the control group and the ozone-exposed group were 0.26 +/- 0.11 and 0.45 +/- 0.34 cm H(2)O/s, respectively. R(L) increased significantly after histamine inhalation both in the control and the ozone-exposed groups. The threshold of histamine (PC(200)) in the ozone-exposed group was significantly lower than that in the control group. A significant swelling of the epithelial cells after histamine inhalation was observed both in the control and the ozone-exposed groups, with a greater increase in the ozone-exposed group compared with the control group. However, no change in wall thickness was observed in the histamine/antihistamine or the ozone/histamine/antihistamine group. CONCLUSION: Our results suggest the possibility that the airway epithelial cell swelling plays a role in the increase in R(L) after histamine inhalation, especially in the presence of airway inflammation.

Airway Resistance↗
PubMed2006

Prediction of intravenous immunoglobulin unresponsiveness in patients with Kawasaki disease.

BACKGROUND: In the present study, we developed models to predict unresponsiveness to intravenous immunoglobulin (IVIG) in Kawasaki disease (KD). METHODS AND RESULTS: We reviewed clinical records of 546 consecutive KD patients (development dataset) and 204 subsequent KD patients (validation dataset). All received IVIG for treatment of KD. IVIG nonresponders were defined by fever persisting beyond 24 hours or recrudescent fever associated with KD symptoms after an afebrile period. A 7-variable logistic model was constructed, including day of illness at initial treatment, age in months, percentage of white blood cells representing neutrophils, platelet count, and serum aspartate aminotransferase, sodium, and C-reactive protein, which generated an area under the receiver-operating-characteristics curve of 0.84 and 0.90 for the development and validation datasets, respectively. Using both datasets, the 7 variables were used to generate a simple scoring model that gave an area under the receiver-operating-characteristics curve of 0.85. For a cutoff of 0.15 or more in the logistic regression model and 4 points or more in the simple scoring model, sensitivity and specificity were 86% and 67% in the logistic model and 86% and 68% in the simple scoring model. The kappa statistic is 0.67, indicating good agreement between the logistic and simple scoring models. CONCLUSIONS: Our predictive models showed high sensitivity and specificity in identifying IVIG nonresponders among KD patients.

Adolescent↗
PubMed2006

Successful rapid discontinuation of immunosuppressive therapy at molecular relapse after allogeneic bone marrow transplantation in a pediatric patient with myelodysplastic syndrome.

The success of allogeneic bone marrow transplantation (allo-BMT) in children with myelodysplastic syndrome (MDS) is mainly affected by relapse. The role of additional immunotherapy for pediatric patients with MDS relapsing after allo-BMT remains to be established. Because immunotherapy is generally more effective for patients who bear a low tumor burden, monitoring of minimal residual diseases (MRD) is essential for early diagnosis at molecular relapse. We report here that a patient with relapsed MDS after allo-BMT was successfully treated by the rapid discontinuation of immunosuppressive therapy at molecular relapse while monitoring Wilms tumor (WT1) gene expression levels. Quantitative analysis of WT1 gene expression appeared to be a useful tool to monitor MRD in the present case.

Adolescent↗
PubMed2006

Study of upper respiratory tract bacterial flora: first report. Variations in upper respiratory tract bacterial flora in patients with acute upper respiratory tract infection and healthy subjects and variations by subject age.

With the appearance of penicillin-resistant Streptococcus pneumoniae, there has been increasing debate concerning antimicrobial treatments for acute upper respiratory tract infection (AURTI) and acute otitis media in children. This study compares the nasopharyngeal bacterial flora in patients with AURTI (AURTI group; 710 subjects) and healthy subjects (HS group; 380 subjects). The comparisons were made between subjects aged 6 years or younger (0-6 subgroup: 330 subjects), between 7 and 74 years (7-74 subgroup: 668 subjects), and 75 years and older (92 subjects), because the subjects were subgrouped as described above dependent on the maturity of the protective immunity. In the HS group 7-74 subgroup, viridans group streptococci, Staphylococcus aureus, coagulase-negative staphylococci, and Corynebacterium sp. with a detection rate of 10% or more were classified as normal nasal flora (NNF), and Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were classified as drum cavity pathogens (DCP). In the 0-6 subgroup, although the detection rate for DCP bacteria in the AURTI group tended to be high, it did not reach a significant difference, whereas the detection rate for NNF bacteria was significantly lower. This trend was also observed to some degree in the other age subgroup. In the 0-6 subgroup, leukocyte infiltration observed with a microscope indicated the closest relationship between S. pneumoniae detection rate and detection quantity. These results suggest that in the 0-6 subgroup the tendency for patients with AURTI to have NNF bacteria as well as DCP bacteria should be taken into consideration.

Acute Disease↗
PubMed2006

A multicenter prospective randomized trial of corticosteroids in primary therapy for Kawasaki disease: clinical course and coronary artery outcome.

OBJECTIVE: To investigate the role of corticosteroids in the initial treatment of Kawasaki disease (KD). STUDY DESIGN: Between September 2000 and March 2005, we randomly assigned 178 KD patients from 12 hospitals to either an intravenous immunoglobulin (IVIG) group (n = 88; 1 g/kg for 2 consecutive days) or an IVIG plus corticosteroid (IVIG+PSL) group (n = 90). The primary endpoint was coronary artery abnormality (CAA) before a 1-month echocardiographic assessment. Secondary endpoints included duration of fever, time to normalization of serum C-reactive protein (CRP), and initial treatment failure requiring additional therapy. Analyses were based on intention to treat. RESULTS: Baseline characteristics of groups were similar. Fewer IVIG+PSL patients than IVIG patients had a CAA before 1 month (2.2% vs 11.4%; P = .017). The duration of fever was shorter (P < .001) and CRP decreased more rapidly in the IVIG+PSL group than in the IVIG group (P = .001). Moreover, initial treatment failure was less frequent (5.6% vs 18.2%; P = .010) in the IVIG+PSL group. All patients assigned to the IVIG+PSL group completed treatment without major side effects. CONCLUSIONS: A combination of corticosteroids and IVIG improved clinical course and coronary artery outcome without causing untoward effects in children with acute KD.

Child↗
PubMed2006

Evaluation of bronchial hyperresponsiveness by monitoring of transcutaneous oxygen tension and arterial oxygen saturation during methacholine challenge in asthmatic children.

BACKGROUND: Bronchial hyperresponsiveness (BHR) is a key feature of asthma, but the measurement of BHR is hampered by the fact that most tests of airway caliber are difficult to conduct at a young age. Methacholine-induced bronchoconstriction is associated with significant hypoxemia, which can be assessed noninvasively by transcutaneous oxygen pressure (tcPO2) and pulse oximetry. Evaluating BHR by monitoring tcPO2 instead of respiratory resistance (Rrs) has been used over a wide age range in childhood. OBJECTIVE: To investigate whether there is a consistent relationship between changes in arterial oxygen saturation (SaO2) and respiratory resistance (Rrs) similar to the relationship between tcPO2 and Rrs during methacholine challenge in young children and to assess the usefulness of SaO2 as a parameter for the indirect measurement of BHR. METHOD: We performed methacholine inhalation challenge by monitoring SaO2, tcPO2 and Rrs in 37 asthmatic children 5 to 7 years of age. Consecutive doses of methacholine were doubled until a 10% decrease in tcPO2 from the baseline was reached. We recorded the cumulative dose of methacholine (Dmin) at the inflection point of tcPO2 (Dmin-tcPO2), SaO2 (Dmin-SaO2), and Rrs(Dmin-Rrs). RESULTS: The mean value of Dmin-Rrs was 4.27 +/- 2.02 units, the mean value of Dmin-tcPO2 was 4.48 +/- 2.01 units, and the mean value of Dmin-SaO2 was 4.57 +/- 0.20 units. Inhalation of increasing doses of methacholine raised Rrs curvilinearly and depressed tcPO2 and SaO2. There were no significant differences between any of the parameters. There were significant relationships between Dmin-tcPO2 and Dmin-Rrs (r = 0.914, p < 0.001) and between Dmin-SaO2 and Dmin-Rrs (r = 0.905, p < 0.001) and a relationship between Dmin-tcPO2 and Dmin-SaO2 (r = 0.949, p < 0.001). CONCLUSION: We concluded that measurement of SaO2 and/or tcPO2 during methacholine inhalation challenge may be used to assess bronchial hyperresponsiveness. This study showed that both SaO2 and tcPO2 monitoring are safe, useful, and tolerable for use in children who are too young to cooperate with lung function tests.

Asthma↗
PubMed2006

Effect of aging on the relationship between asthma severity and bronchial hyperresponsiveness in children with asthma.

An association between asthma and bronchial hyperresponsiveness (BHR) has been demonstrated. It is possible that the relationship between asthma severity and BHR in children with asthma is different in infants and in adolescents. The aim of this study is therefore to evaluate the effect of aging on the relationship between the severity of asthma and BHR in children with asthma. We measured BHR in 386 subjects ranging from 2 to 20 years of age. The subjects consisted of 323 children with asthma (boys:girls = 193:130, mean age 9.7 years) and 63 age-matched controls (boys:girls = 25:38, mean age 8.2 years). BHR was measured using the methacholine inhalation challenge by measuring the transcutaneous oxygen pressure (tcPO2) in children less than 6 years of age (Dmin-PO2) and by measuring the respiratory resistance (Rrs) in children 6 years of age and older (Dmin-Rrs). Throughout the whole age range, both the Dmin-PO2 and Dmin-Rrs in each asthma severity group were higher than those in the controls. In the asthmatics aged 2-5 years, the Dmin-PO2 levels in the mild asthma group were higher than those in the moderate and severe asthma groups (p < 0.001, p < 0.001, respectively), and the Dmin-PO2 levels in the moderate asthma group were also higher than those in the severe asthma group. This tendency was also found in the age ranges of 6-9 years and 10-13 years. In the asthmatics aged 14-20 years, the Dmin-Rrs levels were not significantly different among the three groups. Taken together, these data show that aging has an effect on the relationship between the severity of asthma and BHR during childhood and that BHR may not be the sole determinant for the severity of asthma in adolescence.

Adolescent↗
PubMed2006

Identification and functional analysis of novel inactivating thyrotropin receptor mutations in patients with thyrotropin resistance.

OBJECTIVE: We identified and analyzed novel thyrotropin (TSH) receptor mutations in three Japanese families with resistance to TSH. DESIGN: The TSH receptor gene was sequenced and the mutations were determined. The mutant TSH receptors were transfected into COS-7 cells, and their functions were analyzed. PATIENTS: The patients were compound-heterozygotes for the R450H mutation and novel mutations in the TSH receptor gene. The first patient was a compound-heterozygote for R450H and V473I. The second sibling possessed R450H and R519C. The third sibling had R450H and R519G. RESULTS: The R450H mutant exhibited moderately impaired receptor functions and a moderately decreased cell surface expression in agreement with previous results. The V473I mutant exhibited an almost normal TSH binding, a slightly decreased cyclic adenosine monophosphate (cAMP) response, a moderately decreased inositolphosphate (IP) response, and an almost normal cell surface expression. TSH binding and TSH stimulation of cAMP and IPs were markedly decreased in the R519C and R519G mutants. Cell surface expression was decreased in the R519C mutant and negligible in the R519G mutant. All of these mutants showed normal intracellular synthesis of TSH receptors. CONCLUSIONS: These novel inactivating mutations contribute to understanding of the structure-function relationship of the TSH receptor. To date, all of the patients with TSH resistance resulting from TSH receptor mutations identified in Japan possessed the R450H mutation at least in one allele. These observations suggest that the R450H mutation is a commonly observed TSH receptor mutation in patients with TSH resistance in Japan.

Animals↗
PubMed2006

Effect of formula thickened with locust bean gum on gastric emptying in infants.

AIM: We investigated the effects of milk-based formulas thickened with two different concentrations of locust bean gum on gastric emptying in infants with recurrent regurgitation episodes. METHODS: Thirty-nine infants with three or more episodes of regurgitation per day but no complications who were fed mainly with infant formula were studied. We first compared gastric emptying in infants fed with formulas thickened with two different concentrations of locust bean gum (HL-350, 0.35 g/100 mL; HL-450, 0.45 g/100 mL) or a regular formula (HL-00). To evaluate gastric emptying, we measured antral cross-sectional areas ultrasonographically at various time points after feeding. Next, to investigate the clinical effect of thickened formulas on regurgitation episodes, 27 infants with episodes were assigned randomly to receive HL-350 and HL-00 or HL-450 and HL-00 for 1 week each. RESULTS: Antral cross-sectional areas at 60, 90, 120 and 150 min with HL-450, and at 60 min with HL-350, were greater than with HL-00. The median gastric emptying rate at 120 min with HL-450 (52.8%) was lower than with HL-00 (97.9%; P = 0.0019), while HL-350 (80.3%) and HL-00 did not differ significantly. The mean number of regurgitation episodes was significantly smaller when infants were fed with either HL-350 or HL-450 than with HL-00. CONCLUSIONS: HL-450, a thickened formula with typical commercially available concentrations of locust bean gum, slowed gastric emptying in infants with gastroesophageal reflux.

Female↗
PubMed2006

A randomized open-label comparative study of montelukast versus theophylline added to inhaled corticosteroid in asthmatic children.

BACKGROUND: Inhaled corticosteroids (ICSs) are widely used in combination with other classes of drugs for treatment of childhood asthma. The efficacy and the safety of montelukast added to low-dose ICS therapy were compared with those of sustained-release theophylline added to low-dose ICS therapy in asthmatic children in the present study. METHODS: Following the 2-week run-in period, 6-to 14-year old patients receiving treatment with ICSs were randomized to treatment for 4 weeks with either montelukast 5 mg once daily or sustained release theophylline 5-8 mg/kg (dry syrup) or 100-200 mg (tablet) twice daily. Patients also received a fixed dose of ICS throughout the run-in and treatment periods. The primary efficacy endpoint was the change from baseline in peak expiratory flow (PEF) at Week 2. RESULTS: A significant increase in morning PEF was observed in the add-on montelukast group as compared with the add-on theophylline group at Week 2 (change from baseline of 22.8 L/minvs. 8.7 L/min; p = 0.041 for between-group difference) and at Week 4 (31.0 L/minvs. 9.8 L/min; p = 0.012). A significant increase in evening PEF was observed in the add-on montelukast group as compared with the add-on theophylline group at Week 4 (24.7 L/minvs. 8.7 L/min; p = 0.027). There were no significant differences between the treatment groups in incidences of clinical and laboratory adverse experiences. CONCLUSIONS: The results indicate that montelukast added to low-dose ICS is an effective and safe option for the treatment of asthma in children.

Acetates↗
PubMed2006

[Asthma Insights & Reality in Japan 2005].

BACKGROUND: This Asthma Insights & Reality in Japan survey was conducted to access the achievement of asthma control by patients and current status of asthma treatment in 2005. METHODS: This was cross-sectional, randomized-digit-dial household telephone survey, conducted between September and December 2005. RESULTS: A total 400 adults (mean 52.2 years) and 400 parents of children (mean 8.2 years) with asthma were interviewed by telephone. More than 40% of these patients reported having daytime asthma symptoms and over 30% in nighttime symptoms with awakening. Asthma episodes, i.e. hospitalization, emergency room visit, unscheduled visit, work/school absence were observed in 7, 4, 33, 29% of total patients during the past year, respectively. Eighteen percent of adult and 8% of children used inhaled corticosteroid. Awareness of peak-flow meter and experience of lung function test were low. CONCLUSION: The rate of patients who experienced asthma symptoms or episodes tended to decrease, and use of inhaled corticosteroids seemed to be increased since 2002 when a similar survey took place. However, asthma remains poorly controlled and the current level is still far from achieving the goal of asthma management objected by the Japanese guidelines. Further dissemination of standardize therapy in compliance with the guideline is required.

Administration, Inhalation↗
PubMed2005

Effect of disodium cromoglycate on airway mucus secretion during antigen-induced late asthmatic responses in a murine model of asthma.

BACKGROUND: Disodium cromoglycate (DSCG) is known to inhibit both immediate and late asthmatic responses (IAR and LAR). However, its effect on mucus hypersecretion is unknown. Using a murine model of asthma, we aimed to determine whether mucus secretion increased during IAR and LAR. We also studied the potency of DSCG in inhibiting mucus secretion and on airway eosinophilia. METHODS: Mice were subjected to initial intraperitoneal sensitization and airway challenge to ovalbumin (OVA) and then provoked by additional exposure to OVA. Some mice were pretreated with aerosolized DSCG (20 mg/ml) 1 h before the provocation with OVA. After serial measurements of enhanced pause (Penh), an indicator of airflow obstruction, serum samples and bronchoalveolar lavage fluids (BALF) were collected. Then, the lungs were excised and a morphometric analysis for mucus hypersecretion was performed. RESULTS: A biphasic increase in Penh (IAR and LAR) was observed in sensitized animals after provocation with OVA. Airway eosinophilia was observed during both responses. Intraluminal mucus significantly increased during LAR, but not during IAR. DSCG significantly attenuated both IAR and LAR, and significantly inhibited the increase in intraluminal mucus during LAR, but had no effect on eosinophilia in BALF. CONCLUSION: Our results suggest that airway hypersecretion may be involved as a component of airflow obstruction during LAR, and that this is unlikely during IAR. DSCG may be effective in reducing excessive airway mucus caused by exposure to allergens.

Airway Obstruction↗
PubMed2005

Characteristic features of allergic airway inflammation in a murine model of infantile asthma.

BACKGROUND: The pathophysiology of infantile asthma may differ from that in older children or in adults, partly because of the different immune response depending upon maturation. In adult mice, the sensitizing dose of antigen is known to be critical to the polarized development of helper T cell subsets and allergic airway inflammation. We wanted to know the characteristics of allergic airway inflammation of infantile asthma by developing a murine model. METHODS: BALB/C mice at different stages of maturation (juvenile: 3 days after birth; adult: 8 weeks of age) were sensitized with 10 or 1,000 microg ovalbumin (OVA) or vehicle. The animals were then challenged with aerosolized OVA or saline once a day during 6 consecutive days. After the final challenge, bronchial hyperresponsiveness (BHR), bronchoalveolar lavage fluid (BALF), histological changes in the airways and immunological status were examined. RESULTS: In both juvenile and adult animals, sensitization with 10 microg OVA induced the T helper 2 response (elevated IL-4 and decreased IFN-gamma levels). BHR, airway eosinophilia, the inflammatory cell infiltration, goblet cell metaplasia (GCM), and IgE antibody production were more prominent in animals given this dose than 1,000 microg OVA. Among these responses, GCM as well as BALF IL-4, and BHR were comparable between juvenile and adult animals, whereas other parameters were lower in juvenile animals, especially in those given 1,000 microg OVA. CONCLUSION: GCM and, consequently, airway mucus hypersecretion may be an important component of allergic airway inflammation in infantile asthma.

Age Factors↗
PubMed2005

In vivo recording of colonic motility in conscious rats with deficiency of interstitial cells of Cajal, with special reference to the effects of nitric oxide on colonic motility.

BACKGROUND: We recorded in vivo colonic motility in rats with a deficiency of interstitial cells of Cajal (ICC) (Ws/Ws rats) and in wild-type rats (+/+ rats), with special reference to the effects of nitric oxide (NO) on colonic motility in both types of rats, in order to ascertain the role of ICC in colonic motility, and the relationship between NO and ICC in regard to colonic motility. METHODS: Miniature strain-gauge force transducers were sutured on the surface of the ascending and sigmoid colon of Ws/Ws rats and +/+ rats as controls. After 1 week and a fasting period of 24 h, colonic motility in +/+ and Ws/Ws rats was recorded. We also studied the effect of NO on colonic motility in both types of rats, by means of the administration of N-nitro-L-arginine methyl ester (L-NAME) or L-arginine. RESULTS: In +/+ rats, there were contractions with high amplitude and long duration in both the ascending and sigmoid colon. The number, amplitude, and duration of contractions in the ascending colon were 9.9/20 min, 6.1 g, and 22.7 s, respectively. These findings in the sigmoid colon were 5.2/20 min, 5.2 g, and 23.0 s, respectively. The number of contractions in the ascending and sigmoid colon in Ws/Ws rats (2.3 and 1.0/20 min) was significantly lower than that in +/+ rats (P < 0.05). The number of contractions in the ascending and sigmoid colon in +/+ rats (9.7 and 5.1/20 min before treatment) was significantly increased by L-NAME administration (28.7 and 13.9/40-60 min after treatment; P < 0.05), but that in Ws/Ws rats was not influenced. The number of contractions in the ascending and sigmoid colon in +/+ rats (10.2 and 5.2/20 min before treatment) was significantly decreased by L-arginine administration (3.6 and 2.1/40-60 min after treatment; P < 0.05), but that in Ws/Ws rats was not influenced. CONCLUSIONS: ICC must be related to the occurrence of a normal number of colonic contractions. NO may be involved in the inhibitory regulation of colonic motility, and the effect of NO on the occurrence of contractions appears to be mediated by ICC.

Animals↗