Experiments were designed to investigate whether there is any correlation between concentration of plasma nitric oxide and pathological severity of acute rejection after lung allograft.

After single lung allograft, dogs were immunosuppressed with triple standard therapy and divided into 2 groups. Group 1(Immunosuppression ; n=4) was maintained on immunosuppression as controls. In group 2(Rejection ; n=15), triple therapy was discontinued to induce acute rejection from postoperative day 5. Plasma concentration of nitric oxide was measured by chemiluminescence method prior to surgery and at postoperative day 9. At postoperative day 9, dogs were sacrificed and rejection was graded pathologically by a working formulation for the standardization of nomenclature in the diagnosis of heart and lung rejection: lung rejection study group.

Plasma nitric oxide level of day 9 was compared to that of prior to surgery in each group. Correlation between plasma nitric oxide level and pathological grade of acute rejection at day 9 in group 2(Rejection) was examined.

In group 2(Rejection), plasma nitric oxide level fo day 9 was elevated significantly, compared to that of prior to surgery(12.28±2.10 vs 6.46 0.57µM/L ; p<0.05).But plasma nitric oxide level of day 9 didn't significantly correlate with the pathological grades of rejection in group 2(Spearman's coefficient r=-0.2094 ; p>0.05).

Plasma concentration of nitric oxide was elevated during acute rejection, but didn't correlate with the pathological severity of rejection.

The aim of this study was to investigate whether or not endothelin-1 content of bronchoalveolar lavage was elevated in allografted lungs during acute rejection.

After single lung allotransplantation, dogs were immunosuppressed with triple standard therapy and divided into 2 groups. Group 1(Immunosupression ; n=4) was maintained on immunosuppression as controls. In group 2(Rejectin ; n=13), triple therapy was discontinued to induce acute rejection from postoperative day 5.

At postoperative day 9, broncholaveolar lavage was done through bronchoscopy in native unoperated lung and transplanted lung in group 1. Bronchoalveolar lavage was repeated in group 2 in the same way. Endothelin-1 content of bronchoalveolar lavage was measured by radiommunoassay.

Endothelin-1 content in transplanted lung of group 2 was compared to that of transplanted lung of group 1 and to that of native unoperated lung of group 2.

Endothelin-1 content of bronchoalveolar lavage in transplanted lung of group 2 was comparable to that of group 1(42.18±26.39 vs 3.08±3.08pg/ml ; p=0.08). Endothelin-1 content of bronchoalveolar lavage in transplanted lung of group 2 was comparable to that of native unoperated lung of group 2(42.18±26.39 vs 3.74±2.62pg/ml ; p=0.07).

Endothelin-1 content of bronchoalveolar lavage in transplanted lung was altered during acute rejection, but without statistical significance.

Experiment was designed to compare cellular profile of bronchoalveolar lavage following induced bacterial infection, acute rejection and acute rejection plus bacterial infection after lung allotranplantation.

After single lung allotransplantation, dogs were immunosuppressed with standard triple therapy and divided into 4 groups. Group I(n=4) was maintained on immunosuppression as controls. In group II(n= 6), infection was induced by bronchoscopic inoculation of E. coli at postoperative day 5. In group III(n=6), triple therapy was discontinued to induce acute rejection from postoperative day 5. In group IV(n= 8), triple therapy was discontinued and bacterial infection was induced by bronchoscopic inoculation of E coli at postoperative day 5.

At postoperative day 9, bronchoalveolar lavage was obtained in the native and transplanted lung resprctively through bronchoscopy. Total cell count and differential cell count of bronchoalveolar lavage were compared in four groups.

In the native lung, there was no significant difffrence in total cell count and differential cell count in four groups. In the transplanted lung, total cell count of group II(Infection) was increased, compared to group III(Rejection) (p <0.05). In the transplanted lung, differential neutrophil count of group II(Infection) and group III(Rejection) were increased, compared to group I(Immunosuppression) (p <0.05). In the transplanted lung, differential macrophage count of group II(Infection), III(Rejection) and IV(Rejecion plus Infection) were decreased, compared to group I(Immunosuppuression) (p<0.05).

Cellular profile of bronchoalveolar lavage reflected the pathological process ofinfection or acute rejection following lung allotransplantation in the transplanted lung. But conventional total and differential cell counts had limitation to differentiate either process.

This study was aimed to investigate whether there is any change in palsma nitric oxide during acute rejection of infection after lung allotransplantation.

After lung allotransplantation, dogs were immunosuppressed with standardized triple therapy and divided into 3 groups : in group 1(control: n=4), immunosuppression was maintained; in group 2(n=7), triple therapy discontinued to induce acute rejection at the postoperative day 5; in group 3(n=6), infection was inudced by bronchoscopic inoculation of E. coli at the postoperative day 5. Plasma nitric oxide was measured by chemiluminescene method prior to surgery(day 0), and at postoperative day 5 and 9. In each group, plasma nitric oxide level at day 9 was compared to that at day 0. Plasma nitric oxide levels at day 9 were compared in three groups.

During acute rejection period, plasma nitric oxide concentration was found to be elevated significantly at postoperative day 9, compared to day 0(11.52±2.58 vs 6.01±0.88uM/L ; p<0.05). However, plasma nitric oxide concentration wasn't altered by the E. coli-induced infection(14.53±5.19 vs 6.12±0.98uM/L ; p>0.05). Plasma nitric oxide of day 9 weren't different in three groups(p>0.05).

Plasma nitric oxide may be a good marker for acute rejection after allotrans-plantation, but not for infection.