胸水ターンオーバーに対するノルアドレナリンの影響

抄録

The aim of this study is to analyze pleural fluid turnover with changes of blood flow distribution in the tissues surrounding the pleural space with noradrenaline instillation into the space. Experimental animals were divided into four groups; namely, (1) normal dogs with artificial pleural fluid (normal group, 5 dogs), (2) normal dogs with artificial pleural fluid containing 4mg of noradrenaline (NAd group, 6 dogs), (3) dogs with tetracycline-induced pleuritis with artificial pleural fluid (Tc-Pl group, 4 dogs) and (4) dogs with tetracycline-induced pleuritis with artificial pleural fluid containing 4mg of noradrenaline (Tc-Pl+NAd group, 4 dogs). Artificial pleural fluid consisted of 250ml of saline containing indocyanine green (ICG) 1mg/dl and para-amino hippurate (PAH) 20mg/dl as markers. The experiment started with instillation of artificial pleural fluid under air-tight conditions into the left pleural space. In the case of the pleuritis group, the artificial pleural fluid was instilled into the space 3 hours after injection of tetracycline into the left pleural space, completely evacuating inflammatory exudate due to pleuritis. The concentrations of respective markers were measured at regular interval and PAH clearance, lymphatic flow and extralymphatic flow were calculated.
In the normal group, the concentration of PAH decreased rapidly with a half-life of 154.0±8.0 (S. E.) min, while the concentration of ICG remained unchanged. The PAH clearance of this group was 5.27±0.18ml/hr/kg, the extralymphatic flow was 0.02±0.15ml/hr/kg and the lymphatic flow was 2.03±0.28ml/hr/kg.
In the Tc-Pl group, PAH clearance was double that of the normal group, the extralymphatic flow was 1.30±0.22ml/hr/kg and the lymphatic flow was 1.96±0.16ml/hr/kg. In the Tc-Pl+NAd group, the dynamics of pleural fluid were almost same as in the normal group.
In the NAd group, PAH clearance and lymphatic flow decreased to half that of the normal group. Extralymphatic flow was 0.09±0.05ml/hr/kg.
These results suggest that vascular constriction in surrounding tissues of the pleural space suppresses the turnover rate of pleural fluid, and supports our thesis that the contact surface around pleural fluid affects pleural fluid turnover anatomically and physiologically.