Planimetric analysis of redear sunfish (Lepomis microlophus) hepatopancreas following selenium exposure

Abstract

AbstractA real ratios of pancreas cells to liver cells (P/L ratios) were determined planimetrically and compared with selenium accumulated in the hepatopancreas (liver and associated exocrine pancreas) of redear sunfish (Lepomis microlophus). Fish were collected from four locations in Martin Lake, Texas, and from a reference lake 8 km upstream in the same drainage system. Fish collected from selenium‐contaminated areas in Martin Lake had significantly higher P/L ratios than did reference fish. The increase in the P/L ratios could be explained by either pancreatic cell hyperplasia or parenchymal hepatocyte necrosis and cell loss. Since a previous publication documented both central necrosis with loss of parenchymal hepatocytes and architectural disorganization and endoplasmic reticulum changes in the exocrine pancreas cells of these same redear sunfish, both changes probably occurred simultaneously. However, in this study, P/L ratios were not correlated with selenium levels in the hepatopancreas. This contrasts with published data regarding hematological changes, condition factors, and relative hepatopancreas weight for the same redear sunfish collected for this study. Relative ratios of pancreatic cells to liver cells determined in this study, therefore, were less accurate in pinpointing biological changes due to selenium than were the other parameters previously published using these same fish.