Alberto Domezain

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The possible repercussions of osmoregulatory processes on some indicators of classical and oxidative stress were examined during gradual acclimation of sturgeons (Acipenser naccarii) to full seawater (35% salinity) and after a period of 20 approximately days at this salinity. Erythrocyte constants and levels of cortisol, protein and glucose in the plasma(More)
Modifications in the chloride (mitochondria-rich) and pavement cells of the gill epithelia of the Adriatic sturgeon Acipenser naccarii after their transfer under hypertonic environmental conditions (salinity 35) were examined by light and electron microscopy. In contrast to freshwater specimens, seawater-acclimated fish showed a marked increase in the(More)
The sturgeon is an ancient species of fish that thrives in a wide range of ecological environments, from freshwater to seawater. Basic in this process of adaptation is the ability of the kidney to control fluid filtration and urine formation. However, the morphological basis of this process is mostly unknown. The aim of the present study was to use(More)
The present study examines the particular metabolic strategies of the sturgeon Acipenser naccarii in facing a period of prolonged starvation (72 days) and subsequent refeeding (60 days) compared to the trout Oncorhynchus mykiss response under similar conditions. Plasma metabolites, endogenous reserves, and the activity of intermediate enzymes in liver and(More)
Enzymatic antioxidant activities (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase) and lipid peroxidation were determined in different tissues (gills, heart, digestive tract, liver, white muscle, skin, red blood cells, swimbladder) of trout (Oncorhynchus mykiss) and sturgeon (Acipenser naccarii). Total tissue antioxidant(More)
Previous work showed that in the adult sturgeon an intrapericardial, nonmyocardial segment is interposed between the conus arteriosus of the heart and the ventral aorta. The present report illustrates the ontogeny of this intermediate segment in Acipenser naccarii. The sample studied consisted of 178 alevins between 1 and 24 days posthatching. They were(More)
The cell nucleus is divided into chromosome territories and the extrachromosomal domain. The latter includes several structural and functional compartments involved in RNA processing and transport. Morphological and cytochemical analyses of the cell nucleus in sturgeon podocytes revealed the existence of a previously uncharacterised nuclear compartment. It(More)
The digestive enzyme activities were determined in Adriatic sturgeon and rainbow trout during starvation and refeeding period. Overall, the digestive enzyme activities are affected in the same sense in both species. The protease and lipase activities were decreased later than amylase activity. Even after 1 month of starvation, both species would be prepared(More)
Variations of Na(+)/K(+)-ATPase activity and fatty-acid composition in the gills of the sturgeon Acipenser naccarii subjected to progressive acclimation to full seawater (35 ppt) were determined in relation to the hypo-osmoregulatory capacity of this species in the hyperosmotic medium. Blood samples were taken and gills arches were removed at intermediate(More)
In acipenserids, crypt cells (CCs) have only been observed in juvenile specimens, and it has not been clarified whether they differentiate along with olfactory receptor neurons (ORNs) during the lecithotrophic stage or during later development stages. Furthermore, no detailed optical microscopy (OM) or electron microscopy study on the development of CCs has(More)