Splenic atrophy in experimental severe acute pancreatitis

In severe acute pancreatitis, immunologic impairment is supposed to be linked to the development of subsequent infectious complications.

To examine alterations of spleen in rat experimental severe acute pancreatitis.

Severe necrotizing pancreatitis was induced by retrograde injection of 3% sodium deoxycholate into the biliopancreatic ducts of male Wistar rats.

In the rats with pancreatitis 12 and 24 hours after the induction, splenic weights were significantly lower than those of sham-operated rats. Numbers of splenocytes were also significantly reduced simultaneously. By in situ nick-end labeling, DNA fragmentation enzyme linked immunosorbent assay (ELISA), and DNA electrophoresis, no apoptosis was detected on the splenocytes from the rats with pancreatitis 6, 12, and 24 hours after the onset. Peripheral lymphocytes in the rats with pancreatitis were significantly decreased 6, 12, and 24 hours after the onset compared with those in sham-operated rats. With antecedent splenectomy, peripheral lymphocyte counts 12 hours after the onset were significantly lower than those in rats who had not undergone splenectomy. Moreover, nuclear fragmentation was noted, and DNA fragments were significantly increased in peripheral lymphocytes at 6 hours in sodium deoxycholate pancreatitis.

These results indicate that splenic atrophy resulting from splenocyte reduction occurs in rat experimental severe acute pancreatitis. It is suggested that splenocytes are recruited into systemic circulation in response to peripheral lymphocyte reduction as a result of apoptosis.