effect of partial hepatectomy on the thymus gland and cervical lymph node of male albino rat

ABSTRACT

An increasing number of hepatic resection is being performed as potential curative surgery for both 1ry and 2ry liver tumors and could reach about 70-80% of the liver size. The study aimed to investigate the histological and the immunohistochemical effects of partial hepatectomy [PH] on the thymus gland and the cervical lymph node [LN] of male albino rat as parts of the immune system. Forty male albino rats [130-150 gm] were divided into 4 groups of 10 rats each. The first was reserved as control. The animals of the other 3 groups were subjected to 70% PH. Then, they were sacrificed at 3, 7 and 14 days after the operation. The thymus and cervical lymph nodes were dissected. One lobe of thymus and one cervical lymph node were kept for staining with HandE. The other lobe of the thymus and another cervical lymph node were processed to make single cell suspension and cytospining. Then, they were stained with immuno-peroxidase stain for anti-proliferating cell nuclear antigen [PCNA antibody]. There was depletion of lymphocytes in the thymic cortex and in the lymphoid follicles of the cervical lymph node on day 3 of PH together with significant decrease of their weight. There was a significant decrease of the number of PCNA positively stained cells, as it reached about half the control value in both thymus and cervical lymph node on the same day. Regeneration started at day 7 PH as the depleted areas decreased in addition to appearance of large lymphocytes in the cortex of both thymus and cervical lymph node. This was parallel to the significant increase of the thymic weight and return of the LN weight to its control value. The number of PCNA positively stained cells was significantly increased to exceed double the control value in both thymus and cervical lymph node. Then, these cells decreased towards the 14[th] day. It could concluded that PH decreased the immune system for few days after the operation although further studies are needed to know which type of T-cells is liable to affection by PH