The effect of calcitonin gene-related peptide (CGRP), a neuropeptide, on the apoptosis of murine thymocytes was investigated. CGRP enhanced apoptosis of thymocytes beyond the spontaneous level at ...concentrations of 10
−11 M or higher, and the effect attained a plateau at 10
−9 M, mainly by stimulating cAMP formation. Implication of cAMP-independent mechanism was also suggested in the CGRP-induced apoptosis. Flow cytometric analysis revealed that CGRP caused apoptosis preferentially in CD4
+ 8
+ thymocytes. In addition, RNA and protein synthesis was required for apoptosis induced by CGRP.
We investigated the effect of several opioid peptides on the activation of murine peritoneal exudate macrophages (M phi) in vitro. M phi were treated with interferon (IFN) as a priming agent and ...bacterial lipopolysaccharide (LPS) as a triggering agent in the presence or absence of opioid peptides. M phi activation was assessed by their tumoricidal activity. When treatment with IFN and LPS resulted in a high level activation of M phi, dynorphin-A exerted no further enhancing effect. When treatment induced only weak activation, however, dynorphin-A augmented the M phi activation. Leucine-enkephalin, methionine-enkephalin, and also beta-endorphin had augmenting effects. An opioid receptor antagonist, naloxone, reduced the effect of dynorphin-A and beta-endorphin. When M phi were treated sequentially with IFN and LPS, beta-endorphin operated in combination with LPS only. Moreover, beta-endorphin was effective for already activated M phi. These results indicate that opioid peptides act on M phi via classical opioid receptors, and that responsiveness to opioid peptides is induced in the triggering stage of M phi activation.
The purpose of the study was to investigate whether the use of hyperoxic gas generator is effective in recovery from fatigue after exercise. Ten healthy male subjects performed two trials; each ...consisting of ten minutes of exercise at a workload of 65%VO_2max on a bicycle ergometer and twenty minutes of recovery. The hyperoxic gas generator was applied to the one trial during recovery in order to determine its effect. The gas generator used in this study was fitted with a special film to raise oxygen concentration of the air and sent the concentraed air (30%O_2) through a pipe. The end of the pipe was set in front of the nostril within a couple of cm in accordance with the user's manual. Blood samples were collected at 3, 6, 10, 15 and 20 min after each exercise session, and blood lactate concentration was measured. Pulmonary ventilation and heart rate were measured during the experiments. The subjects were questioned as to their condition afler each trial using a questionnaire. With regard to ventilation, heart rate and blood lactate concentration responses during recovery, no significant difference was found between the cases using ie hyperoxic gas and those not using it. The questionnaire investigation showed no significant difference either. These results indicate that the hyperoxic gas generator is not effective in the recovery after exercise fatigue under these experimental conditions.
Physiological responses to riding a scooter (scootering) are compared with walking, running and cycling at three different treadmill speeds (80, 110 and 140m min-1) and slopes (0%, 4% and 8 %) . Five ...healthy male college students performed all exercises at different intensities in four trials a day, one or two days a week. Each experiment comprised of a 5-20 minute resting period, followed by 3 minutes of exercise and 10-50 minute recovery time. Apart from stationary cycling to measure maximal oxygen uptake, all exercises were performed on a treadmill. Heart rate (HR), oxygen uptake (VO2), carbon dioxide production (VCO2), pulmonary ventilation (VE), respiration rate (RR) and respiratory exchange ratio (RER) were measured every 15 seconds, and averaged using a computerized breath-by-breath expired gas monitor. From these measurements, the ventilation equivalent for CO2 (VE/VCO2) was calculated. No significant differences in the HR-VO2 relation with exercise intensity were observed among the different types of exercise. The slopes of the regression lines for VE-VO2 and RER-VO2 in scootering were steeper than those in other exercises (p<0.05) . A significant correlation was noted between stroke frequency and RR in scootering (R=0.727, p <0.001) . Measurement of the changes in VE/VCO2 during scootering at 73, 80 and 90% VO2max revealed a notably (p<0.05) larger ‘short period of depression’ (undershooting) with a peak around 30 seconds after exercise, which was rarely observed with the other exercises examined. These results suggest that the cardiorespiratory responses to scootering differ from those to walking, running and cycling, due to the unique locomotion pattern of this vehicle.
Wide-angle X-ray scattering (WAXS) patterns of segmented poly(ether ester) fibers, which were made from poly(tetramethylene glycol) (PTMG) and poly(tetramethylene terephthalate) (PTMT), under tensile ...stress were studied to clarify the effect of the amorphous region on reversible crystal deformation of PTMT crystallites in the copolymers. The transition between the α and β crystal phases was observed around 800 Kg/cm2 in tensile stress with various copolymers. The transition was not observed in PTMG rich copolymers in which the amorphous region was too soft to bear this level of tensile stress.
In the course of study to obtain murine dendritic cell lines using oncogenic retroviruses, we have established several immortalized cell lines with characteristics different from those of dendritic ...cells. The transformants were mainly round nonadherent cells, capable of growing in soft agar, and negative for nonspecific esterase activity. Profiles of cell surface antigens were examined by indirect immunofluorescence technique. The cell lines were positive for Fc receptor (2.4G2), J11d (J11d.2), and B220 (RA3‐3A1/6.1) antigens and negative (or dull positive in small percentages) for Ia (M5/144.15.2), IL‐2 receptor (3C7), Thy‐1 (B5‐5), Mac‐1 (M1/70.‐15.11.5), and macrophage (F4/80) antigens. They were negative for both surface and cytoplasmic immunoglobulins. Several clones were established from these transformant cell lines and cell surface antigens were examined. Antigenic profiles of these clones were very similar to those of the parental cell lines. Some of these clones, however, seemed to increase their Ia antigen expression. The results suggest that the transformants originated from early B‐lineage cells.
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