A stereological study along the year on the hepatocytic peroxisomes of brown trout (Salmo trutta)

• Type: Article in International Scientific Journal
• Date: 1999

Authors

rocha, e (Author) ICBAS; lobo-da-cunha, a (Author) ICBAS; monteiro, raf (Author) Other; silva, mw (Author) Other; oliveira, mh (Author) Other

Journal

Title: Journal of Submicroscopic Cytology and Pathology

Vol. 31

Pages: 91-105

ISSN: 1122-9497

Publisher: N I E Nuova Immagine Editrice

Indexing

ISI Web of Knowledge - 25 Citations

Scopus - 31 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-001-5XP

Abstract (EN): Studies on peroxisomes of fishes are very scarce, and the influence of both gender and season on their morphology is virtually unknown. A stereological approach was then performed on the hepatocytic peroxisomes of 3-year-old brown trout. Males and females were collected in February tend of spawning season), May (early vitellogenesis), and September (advanced vitellogenesis). Liver was fixed by perfusion, and tissue was processed for catalase cytochemistry. Manual stereology was used on electron microscopic photographs for estimating relative volumes, surfaces and numbers of peroxisomes. Their mean surface, volume and spherical equivalent diameter were secondarily derived. Total volume, surface and number of peroxisomes per hepatocyte were also computed (cell volume being used as intermediate value). AU parameters relative to size displayed statistical significant changes, generally by season and gender interaction; seasonal changes were more pronounced in Females. In February and in September female peroxisomes were smaller and had lesser total volumes and surfaces than in males; in May, both genders were virtually identical. No statistically significant results were obtained in relation to peroxisome number. Strong negative correlations were found between all the size parameters of female peroxisomes and the gonado-somatic index (GSI). In males, only peroxisomal diameter, surface and volume were significantly but fairly positively correlated with the GSI. Similarities and differences existed between brown trout and other species. It was firstly demonstrated that changes in size can occur without modifications in number. In one male, however, unusually large and fewer peroxisomes with loops proved that in brown trout size and numerical changes can occur simultaneously too. Functional implications of morphological data were highlighted, including possible relationships between steroid hormones and peroxisomes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15