The liver of fishes as a target organ of toxic chemicals: a new look at unique structure and function in one of the ‘other’ vertebrates

Abstract

With 25,000 species of fishes, it is accurate to say that most of the livers of the world are tubular in architecture. Architectural similarity exists between the adult teleost hepatic tubule, the exocrine pancreatic acinus, and elements of the fetal and juvenile forms of mammalian liver. The hepatic tubule with its associated microvasculature likely represents the smallest functional unit of this important organ. Vascular–epithelial relationships unique to the tubular architecture may explain differences in acute toxicity following exposure to reference hepatotoxicants. In a dynamic manner, structure/function relationships of this organ will be presented in the context of responses to pollutants. In vitro and in vivo studies will be presented which illustrate the utility of these organs for environmental toxicologic investigations. Analysis of livers of these vertebrates will likely lead to a better appreciation of the origin of the mammalian portal lobule, the classic lobule and the acinus. Gaps exist in our understanding of cell, tissue and liver biology of fishes, and these need to be addressed if we are to understand pollutant responses in marine organisms