Skin Mucus Extracts Research Articles

Demonstration of the mucous hemagglutinin in the club cells of eel skin

Eel epidermis was subjected to immunocytochemical study in order to clarify the origin of mucus hemagglutinin. Skin mucus extract was applied on a Sephacryl S-400 column. The active fractions of the hemagglutinin, which agglutinated rabbit red blood cells, were collected. These fractions were contaminated with a hemolysin. Therefore, after inactivation of the hemolysin by heating at 45°C for 30min, they were reacted with rabbit red blood cells. The agglutinated cells were hemolysed to make a hemagglutinin-cell membrane complex. Rabbits were immunized with the complex, and antisera against the hemagglutinin were obtained. Skin sections of eel were stained immunocytochemically by a peroxidase-antiperoxidase (PAP) method using the rabbit anti-hemagglutinin serum. Positive reaction for the hemagglutinin was seen in club cells, especially in secretory vacuoles. This fact indicates the mucous hemagglutinin is derived from the club cells in eel.

Free amino acid content in the skin mucus of goldfish, Carassius auratus L.: Influence of feeding

1. 1. Free amino acid contents in skin extracts and influence of food and starvation on free amino acid content in skin mucus were analysed in sexually immature goldfish. 2. 2. Free amino acid concentration in skin mucus (91.1 μmol/g dry wt) was higher than in deep skin (54 μmol/g) or in whole skin (56.6 μmol/g) extracts. Free amino acid compositions were very similar in the latter extracts. They both differed from skin mucus extract in taurine, glutamic acid, glycine and histidine relative contents. 3. 3. Free amino acid composition in Zooplankton used to feed goldfish was close to the composition found in corrresponding skin mucus extracts, except in taurine content. 4. 4. Goldfish weighing 3 g (6 months old) and 17 g (1 year old) reared on zooplankton showed similar patterns of free amino acid composition in skin mucus. Comparison with free amino acid composition in skin mucus from goldfish fed on commercial food had big differences in glutamic acid, valine, methionine and lysine relative contents. 5. 5. During fasting, we observed an increase in the amount of mucus secreted and a concomitant decrease of the free amino acid concentration in the secretion. 6. 6. The origin of free amino acids found in skin mucus and their possible role in pheromonal and allelochemical communications of goldfish are discussed.