We studied the psychological stress-reducing effect of chocolate enriched with γ-aminobutyric acid (GABA), on stress induced by an arithmetic task using changes of heart rate variability (HRV) and ...salivary chromogranin A (CgA). Subjects ingested 10 g chocolate enriched with 28 mg GABA (GABA chocolate); 15 min after the ingestion, subjects were assigned an arithmetic task for 15 min. After the task, an electrocardiogram was recorded and saliva samples were collected. HRV was determined from the electrocardiogram, and the activity of the autonomic nervous system was estimated through HRV. The CgA concentration of all saliva samples, an index for acute psychological stress, was measured. From HRV, those taking GABA chocolate made a quick recovery to the normal state from the stressful state. The CgA value after the task in those taking GABA chocolate did not increased in comparison with that before ingestion. From these results, GABA chocolate was considered to have a psychological stress-reducing effect.
To examine the changes in airways in bronchial asthma (BA) during an asthma attack causing death, we performed morphometric analysis of autopsied lungs from three outpatients who died of severe acute ...asthma attacks (group A) and compared these to five patients who died of non-status asthmaticus (group B). Controls (group NL) were four patients who died of diseases other than respiratory disorders. Area proportions of bronchial glands to bronchial wall (gland percent) and of goblet cells to total epithelial layer (goblet percent) and the intraluminal amount of mucus in the airways (MOR) were measured in a paraffin section. There were no significant differences in age, sex, smoking history, duration of BA history, and dosage of glucocorticoids received between groups A and B. Although both groups A and B showed significantly larger values of gland (percent) in the central airways and of inflammatory cell numbers in the airway walls than did group NL, no significant differences were observed between groups A and B. In contrast, markedly significant increases in goblet (percent) and in MOR were observed in group A compared to groups B and NL. These increases in group A were more dominant in the peripheral airway: 30-fold and threefold increases of group B in goblet (percent) and MOR, respectively. Furthermore, MOR significantly correlated with goblet (percent) in the peripheral airways (p<0.05). These findings suggest that a marked increase in goblet cells of the airways is a feature characteristic of patients with BA who die of a severe acute attack.
To partition the central and peripheral airway resistance in awake humans, a catheter-tipped micromanometer sensing lateral pressure of the airway was wedged into the right lower lobe of a 3-mm-ID ...bronchus in 5 normal subjects, 7 patients with chronic bronchitis, 8 patients with emphysema, and 20 patients with bronchial asthma. We simultaneously measured mouth flow, transpulmonary pressure, and intra-airway lateral pressure during quiet tidal breathing. Total pulmonary resistance (RL) was calculated from transpulmonary pressure and mouth flow and central airway resistance (Rc) from intra-airway lateral pressure and mouth flow. Peripheral airway resistance (Rp) was obtained by the subtraction of Rc from RL. The technique permitted identification of the site of airway resistance changes. In normal subjects, RL was 3.2 +/- 0.2 (SE) cmH2O.l-1.s and the ratio of Rp to RL was 0.24 during inspiration. Patients with bronchial asthma without airflow obstruction showed values of Rc and Rp similar to those of normal subjects. Although Rc showed a tendency to increase, only Rp significantly increased in those patients with bronchial asthma with airflow obstruction and patients with chronic bronchitis and emphysema. The ratio of Rp to RL significantly increased in three groups of patients with airflow obstruction (P less than 0.01). These observations suggest that peripheral airways are the predominant site of airflow obstruction, irrespective of the different pathogenesis of chronic airflow obstruction.
We studied the psychological stress-reducing effect of chocolate enriched with -aminobutyric acid (GABA), on stress induced by an arithmetic task using changes of heart rate variability (HRV) and ...salivary chromogranin A (CgA). Subjects ingested 10 g chocolate enriched with 28 mg GABA (GABA chocolate); 15 min after the ingestion, subjects were assigned an arithmetic task for 15 min. After the task, an electrocardiogram was recorded and saliva samples were collected. HRV was determined from the electrocardiogram, and the activity of the autonomic nervous system was estimated through HRV. The CgA concentration of all saliva samples, an index for acute psychological stress, was measured. From HRV, those taking GABA chocolate made a quick recovery to the normal state from the stressful state. The CgA value after the task in those taking GABA chocolate did not increased in comparison with that before ingestion. From these results, GABA chocolate was considered to have a psychological stress-reducing effect.
1. An attempt has been made to test the hypothesis that, in the caudal part of nucleus tractus solitarii (NTS) where carotid
sinus nerve (CSN) afferents project, L-glutamate (Glut) modulates the ...hypoxic ventilatory response. 2. Unanaesthetized, peripherally
chemodenervated (carotid body denervated; CBD) and sham-operated, freely moving rats were used. During peripheral chemoreceptor
stimulation by hypoxia (10% O2 for 30 min) or doxapram (Dox) infusion (2 mg kg-1 (30 min)-1), ventilation was recorded and
successively, under the same conditions, the extracellular Glut concentration (Gluto) in the caudal NTS was measured by
in vivo microdialysis. Gluto was also measured during hyperoxic hypercapnia (10% CO2-30% O2 for 30 min). 3. Furthermore,
the effects on ventilation of exogenous Glut, the NMDA (N-methyl-D-aspartate) receptor antagonist MK-801 or the ionotropic
receptor antagonist kynurenate microinjected into the caudal NTS were investigated in sham-operated rats. 4. In sham-operated
rats, both ventilation and Gluto in NTS were increased during peripheral chemoreceptor stimulation. On the other hand, no
increases in either ventilation or Glut release were observed in CBD rats. In spite of ventilatory augmentation during hypercapnia,
no response of Gluto to hypercapnia was observed in either group. 5. Local Glut application into NTS increased ventilation.
Pretreatment with MK-801 or kynurenate reduced the hypoxic ventilatory response. This reduction in ventilation was mainly
due to the decrease in tidal volume. 6. These results suggest that hypoxia induced the release of Glut in NTS and that this
effect was mediated by arterial chemosensory input.
Axon reflex mechanisms may be involved in the pathogenesis of asthma, but there has been no direct evidence that endogenous tachykinins cause bronchoconstriction in asthmatic subjects. We have ...studied the effect of a tachykinin receptor antagonist (FK-224) on bronchoconstriction induced by inhalation of bradykinin in asthmatic patients. In a double-blind, placebo-controlled, crossover trial, ten subjects with stable asthma were given FK-224 (4 mg) or placebo by inhalation 20 min before challenge with bradykinin (0-1250 μg/ml, five breaths of each concentration) given with 5 min intervals. Bradykinin caused dose-dependent bronchoconstriction in all subjects. FK-224 significantly opposed the bronchoconstrictor effect; the geometric mean of the cumulative concentration required to elicit a 35% fall in specific airway conductance was 5·3 μg/ml after placebo and 40 μg/ml after FK-224 (p<0·001). Inhalation of bradykinin caused coughing in three subjects, which was inhibited by FK-224 in all three. Antagonism of the tachykinin receptor by FK-224 greatly inhibited both bronchoconstriction and coughing induced by bradykinin in asthmatic patients, suggesting that tachykinin release from the airway sensory nerves is involved in responses to bradykinin. Tachykinin receptor antagonists may be useful in the treatment of asthma.
Tumor necrosis factor (TNF) is considered to play a key role in the pathogenesis of allergic disorders. We examined TNF production in human lung fragments after IgE receptor triggering at mRNA and ...protein levels. IgE receptor triggering was performed by sensitizing lung fragments with monoclonal human IgE and then exposing them to anti-human IgE antibody. Cytotoxic activity against L929 cells appeared in the culture supernatant of lung fragments 2 h after IgE receptor triggering and increased for up to 4 h. This cytotoxic activity was completely neutralized by anti-human TNF antibody. Northern blot analysis demonstrated that 1.8-kb TNF mRNA transcripts in sensitized lung fragments were expressed as early as 1 h after IgE receptor triggering and continued up to 4 h. Immunohistochemical analysis revealed TNF localization in tissue mast cells, alveolar macrophages, tissue macrophages, and bronchial epithelial cells. Double staining with anti-TNF antibody and alcian blue clearly identified that lung mast cells are one of the TNF-positive cell types in the pulmonary tissue. With immunoelectron microscopy, TNF immunoreactivity was detected in the rough endoplasmic reticulum and the perinuclear spaces in tissue macrophages, and in the cytosol and the perinuclear spaces in bronchial epithelial cells. In addition, IgE was detected on the cell surface of mast cells, tissue macrophages, and alveolar macrophages. These results suggest that TNF is released from mast cells and pulmonary macrophages through IgE receptor triggering and may play a key role in the allergic reaction in human airway.
Cysteinyl leukotrienes are potent contractile agonists for airway smooth muscle. To examine the relative role of cysteinyl leukotrienes in immediate airway obstruction in human subjects with asthma ...after allergen challenge, we investigated the effect of ONO-1078, a potent receptor antagonist of cysteinyl leukotrienes, on the response.
ONO-1078 and an inactive placebo, in 150-mg capsule form, were administered every 12 hours for 1 week, in a double-blind, cross-over fashion. To examine the effect on the early part of the response, total respiratory resistance (Rrs) was continuously evaluated for 10 minutes after the start of a 1-minute exposure to an appropriate concentration of allergen. Rrs and FEV1.0 were estimated every 10 minutes for 60 minutes after the exposure.
ONO-1078 significantly reduced percent changes in Rrs and FEV1.0 from 20 to 60 minutes after the exposure, as well as percent maximum changes in these indices, although the treatment did not alter the time from the start of allergen exposure to the beginning of elevation of Rrs, the time from the start to the point at which total respiratory conductance decreased by 35% from its baseline value, or percent changes in Rrs or FEV1.0 10 minutes after the exposure.
Therefore, we conclude that cysteinyl leukotrienes primarily mediate a later part of immediate airway obstruction after allergen exposure.
To study the molecular basis of vascular remodeling in pulmonary hypertension, we developed an experimental system in which male Sprague-Dawley rats were exposed to hypoxia for up to 3 wk. Both the ...right ventricular systolic pressure and gravimetric index for right ventricular hypertrophy were higher in rats exposed to hypoxia for 3 wk than those of age-matched control rats (P < 0.01), indicating that pulmonary hypertension was established under conditions used. To examine the possible involvement of platelet-derived growth factor (PDGF) in the pulmonary vascular remodeling caused by hypoxia, we cloned rat PDGF A- and B-chain cDNA and prepared specific cRNA probes. Northern blot analysis revealed that PDGF B-chain mRNA levels in the lungs were increased, reached a maximum of day 1, and were sustained at day 3, whereas PDGF A-chain mRNA levels reached a maximum on day 3. Thus the increase in the PDGF B-chain mRNA level precedes that in the PDGF A-chain mRNA level. These results suggest that the PDGF A- and B-chain products may be coordinately and sequentially involved in hypoxic pulmonary vascular remodeling.
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