Naoharu Sugiura

N-Isopropyl-p-iodoamphetamine receptors in normal and cancerous tissue of the human lung

N-Isopropyl-p-iodoamphetamine (IMP) receptors in normal human lung tissue were characterized using a radioligand binding assay with iodine-125 IMP as the ligand. Saturation binding studies revealed the presence of two binding sites with dissociation constant (Kd) values of 53 ± 2 and 4687 ± 124 nM and maximum binding capacity (Bmax) values of 7 ± 1 and 133 ± 27 pmol/mg protein (n=5) respectively. The IC50 values of various amines were as follows: IMP, 9 × 10−5M; propranolol, 5 × 10−4M; haloperidol, 6 × 10−4M; ketamine, 9 × 10−3M; dopamine, 1 × 10−2M. The IMP receptors of cancerous tissue obtained from human lung also had two binding sites with Kd values of 54 ± 2 and 5277 ± 652 nM and Bmax values of 7±1 and 103 ± 21 pmol/mg protein (n = 3) respectively. There was no significant difference in binding parameters between normal and cancerous lung tissue. These results demonstrate the existence of IMP receptors and suggest that cancer does not affect the nature of IMP receptors in human lung tissue.

Phase differences between chest and mouth flows in patients suffering from pulmonary disease

The phase difference (PD) between mouth flow and chest flow during rest breathing was measured in pulmonary diseased patients using a body box and the results were compared with normal subjects. Whereas the PD increased in patients with chronic pulmonary obstructive disease (COPD) compared to normal subjects, PD was found to be normal in patients with interstitial pulmonary fibrosis (IPF) (Normal: 2.94 +/- 1.25, COPD: 11.32 +/- 4.17*, IPF: 2.62 +/- 1.67 degrees; *P < 0.01). PD correlated well with FEV1.0/VC%, PFR, RV/TLC, VTG and Ra (r: -0.759, -0.672, -0.788, 0.666, 0.606). From an in-depth analysis of the results, we suggest that the factors which increase PD in COPD patients include hyperinflation of the lung, increases in airway resistance and increases in the parallel inhomogeneity of airway resistance accompanied by an unevenness of alveolar pressures. PD was thought to be clinically useful for the evaluation of the pathological stages of COPD because it reflects the overall clinical manifestations in COPD patients.