Morphometric evaluation of rat liver after castration: effects of testosterone.

In men and animals subject to orchiectomy, varying degrees of hypotrophy have often been observed, even involving non-reproductive organs. Liver hypotrophy appears particularly interesting in view of the metabolic alterations that could possibly ensue. We have applied the morphometric approach to the study of this kind of hypotrophy in castrated rats and in animals receiving a substitutive, testosterone-based treatment after castration. The morphometric model adopted was built on the basis of an interactive approach, using an image analyser (IBAS) with specially-designed software, and consists of number and size, as well as surface and volume fractions, of hepatocytes, their nuclei, cytoplasm, and the relevant relation to the sinusoidal bed. The effects of castration were revealed by a reduction of the mean volume of hepatocytes, associated with a reduction of the sinusoidal bed. Such reduction is correspondingly associated with an increase of the extraparenchymal components (endothelia, Glisson capsule). In the testosterone-treated group, while no appreciable symptoms of retrieval were yet observable in the volume of hepatocytes, the sinusoidal bed was instead superimposable onto the control group data as far as both volume and blood/hepatocyte interface were concerned. In the castrated animals the number of hepatocytes per mm3 was found to be increased. The group of testosterone-administered rats also showed a high level for this parameter which, associated with the spread of the capillary bed, could be compatible with a picture of precocious hyperplastic response to the therapy. The correlation between the available morphometric data and the biochemical results which are being currently sought will further clarify the meaning of this phenomenon.