Immune regulatory effect of hepatic factor associated with thymus alteration

This study was carried out to clarify the mechanism of the immune regulatory effect of factors which were liberated from the ischemic damaged liver. By occlusion of the hepatic vessels (hepatic artery and portal vein) for 40 min daily during 5 days to induce the ischemic damage of the liver, reduced thymus weight (50 +/- 5 mg; control, 274 +/- 23 mg) and cell count (0.7 +/- 0.3 X 10(7); control, 3.5 +/- 0.3 X 10(8] and complete differentiation of thymocytes were observed, i.e., helper cells reacting to monoclonal antibody W3/25 were 34 +/- 8% and suppressor/cytotoxic cells to OX-8, 49 +/- 5% (in control W3/25:89 +/- 1%, OX-8:89 +/- 1%). These quantitative and qualitative changes of thymocytes were correspondent to those of animals treated with 40 mg CsA/kg per day for 5 days; however, medication with 10 mg prednisolone/day 5 times could not induce any alteration of thymocyte subpopulation (W3/25:89 +/- 1%, OX-8:87 +/- 1%) although the weight and cell count decreased to 92 +/- 8 mg and 4.1 +/- 0.6 X 10(7), respectively. Furthermore, 5 days after liver allotransplantation (BDE to LEW), the weight and cell count of the thymus were extremely reduced (58 +/- 6 mg, 2.7 +/- 0.2 X 10(7], and thymocyte differentiation was observed (W3/25:56.6%, OX-8:61 +/- 11%). On the other hand, in heart transplantation the atrophy of the thymus was not so strong (105 +/- 28 mg, 1.3 +/- 0.6 X 10(8], and there was no change in the subpopulation (W3/25:89 +/- 2%, OX-8:88 +/- 1%).(ABSTRACT TRUNCATED AT 250 WORDS)