Transintegumentary uptake of d-Galactose, d-Fructose and 2-Deoxy-d-glucose by the lumbricid earthworm Lumbricus rubellus

Biology of the Integument

“…The uptake of neutral, basic, and acidic amino acids by the lumbricid Eisenia /oetida, as re-flected by inhibition studies, is broadly comparable to that observed in marine annelids (Richards and Arme 1979). Uptake of monosaccharides in Lumbricus rubel/us occurs through more than one mediated pathway (Richards and Arme 1980a). Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b).…”

“…Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b). Richards and Arme (1980a) were of the opinion that both epidermal uptake of amino acids, sugars, and fatty acids were non-concentrative; however, this statement was based on tracer uptake data without net fluxes or the epidermal concentrations of endogenous substrate being available, and it may represent an unnecessarily conservative view. Since the electrochemical N a + gradient across the apical epidermal membrane in freshwater annelids is probably directed outward (see Sect.…”

Biology of the Integument

“…The uptake of neutral, basic, and acidic amino acids by the lumbricid Eisenia /oetida, as re-flected by inhibition studies, is broadly comparable to that observed in marine annelids (Richards and Arme 1979). Uptake of monosaccharides in Lumbricus rubel/us occurs through more than one mediated pathway (Richards and Arme 1980a). Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b).…”

“…Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b). Richards and Arme (1980a) were of the opinion that both epidermal uptake of amino acids, sugars, and fatty acids were non-concentrative; however, this statement was based on tracer uptake data without net fluxes or the epidermal concentrations of endogenous substrate being available, and it may represent an unnecessarily conservative view. Since the electrochemical N a + gradient across the apical epidermal membrane in freshwater annelids is probably directed outward (see Sect.…”

Nutrient Absorption in Invertebrates

“…Subsequent studies have, however, provided further evidence for carrier‐mediated uptake of dissolved material into at least some freshwater animals—for example, glucose and glycine uptake into a freshwater bivalve (134) and uptake of amino acids, carbohydrates, and short‐chain fatty acids into freshwater oligochaetes (363, 364, 365), respectively. However, the rates of uptake reported in these studies are very low compared to those typically measured in soft‐bodied marine invertebrates, suggesting that integumental uptake of nutrients is probably not significant in freshwater animals (364). Nevertheless, Thomas et al (451) reported a net accumulation of short‐chain carboxylic acids into the freshwater pulmonate snail Biomphalaria glabrata (the invertebrate host of Schistosoma mansoni ), at rates which suggest that this process could play a role in animal nutrition (see also ref.…”

“…He also reported that glycine accumulation into a brackish water polychaete, Nereis limnicola , was strongly influenced by salinity and that uptake dropped sharply at external chlorosities below approximately 200 mEq · l −1 . Subsequent studies have, however, provided further evidence for carrier‐mediated uptake of dissolved material into at least some freshwater animals—for example, glucose and glycine uptake into a freshwater bivalve (134) and uptake of amino acids, carbohydrates, and short‐chain fatty acids into freshwater oligochaetes (363, 364, 365), respectively. However, the rates of uptake reported in these studies are very low compared to those typically measured in soft‐bodied marine invertebrates, suggesting that integumental uptake of nutrients is probably not significant in freshwater animals (364).…”

Biology of the Integument

“…The uptake of neutral, basic, and acidic amino acids by the lumbricid Eisenia /oetida, as re-flected by inhibition studies, is broadly comparable to that observed in marine annelids (Richards and Arme 1979). Uptake of monosaccharides in Lumbricus rubel/us occurs through more than one mediated pathway (Richards and Arme 1980a). Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b).…”

“…Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b). Richards and Arme (1980a) were of the opinion that both epidermal uptake of amino acids, sugars, and fatty acids were non-concentrative; however, this statement was based on tracer uptake data without net fluxes or the epidermal concentrations of endogenous substrate being available, and it may represent an unnecessarily conservative view. Since the electrochemical N a + gradient across the apical epidermal membrane in freshwater annelids is probably directed outward (see Sect.…”

Nutrient Absorption in Invertebrates

“…Subsequent studies have, however, provided further evidence for carrier‐mediated uptake of dissolved material into at least some freshwater animals—for example, glucose and glycine uptake into a freshwater bivalve (134) and uptake of amino acids, carbohydrates, and short‐chain fatty acids into freshwater oligochaetes (363, 364, 365), respectively. However, the rates of uptake reported in these studies are very low compared to those typically measured in soft‐bodied marine invertebrates, suggesting that integumental uptake of nutrients is probably not significant in freshwater animals (364). Nevertheless, Thomas et al (451) reported a net accumulation of short‐chain carboxylic acids into the freshwater pulmonate snail Biomphalaria glabrata (the invertebrate host of Schistosoma mansoni ), at rates which suggest that this process could play a role in animal nutrition (see also ref.…”

“…He also reported that glycine accumulation into a brackish water polychaete, Nereis limnicola , was strongly influenced by salinity and that uptake dropped sharply at external chlorosities below approximately 200 mEq · l −1 . Subsequent studies have, however, provided further evidence for carrier‐mediated uptake of dissolved material into at least some freshwater animals—for example, glucose and glycine uptake into a freshwater bivalve (134) and uptake of amino acids, carbohydrates, and short‐chain fatty acids into freshwater oligochaetes (363, 364, 365), respectively. However, the rates of uptake reported in these studies are very low compared to those typically measured in soft‐bodied marine invertebrates, suggesting that integumental uptake of nutrients is probably not significant in freshwater animals (364).…”

Biology of the Integument

“…The uptake of neutral, basic, and acidic amino acids by the lumbricid Eisenia /oetida, as re-flected by inhibition studies, is broadly comparable to that observed in marine annelids (Richards and Arme 1979). Uptake of monosaccharides in Lumbricus rubel/us occurs through more than one mediated pathway (Richards and Arme 1980a). Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b).…”

“…Also the epidermal transport of acetate by this species involves a specific system, as evident from the inhibitory effects of formate and propionate (Richards and Arme 1980b). Richards and Arme (1980a) were of the opinion that both epidermal uptake of amino acids, sugars, and fatty acids were non-concentrative; however, this statement was based on tracer uptake data without net fluxes or the epidermal concentrations of endogenous substrate being available, and it may represent an unnecessarily conservative view. Since the electrochemical N a + gradient across the apical epidermal membrane in freshwater annelids is probably directed outward (see Sect.…”

Nutrient Absorption in Invertebrates

“…Subsequent studies have, however, provided further evidence for carrier‐mediated uptake of dissolved material into at least some freshwater animals—for example, glucose and glycine uptake into a freshwater bivalve (134) and uptake of amino acids, carbohydrates, and short‐chain fatty acids into freshwater oligochaetes (363, 364, 365), respectively. However, the rates of uptake reported in these studies are very low compared to those typically measured in soft‐bodied marine invertebrates, suggesting that integumental uptake of nutrients is probably not significant in freshwater animals (364). Nevertheless, Thomas et al (451) reported a net accumulation of short‐chain carboxylic acids into the freshwater pulmonate snail Biomphalaria glabrata (the invertebrate host of Schistosoma mansoni ), at rates which suggest that this process could play a role in animal nutrition (see also ref.…”

“…He also reported that glycine accumulation into a brackish water polychaete, Nereis limnicola , was strongly influenced by salinity and that uptake dropped sharply at external chlorosities below approximately 200 mEq · l −1 . Subsequent studies have, however, provided further evidence for carrier‐mediated uptake of dissolved material into at least some freshwater animals—for example, glucose and glycine uptake into a freshwater bivalve (134) and uptake of amino acids, carbohydrates, and short‐chain fatty acids into freshwater oligochaetes (363, 364, 365), respectively. However, the rates of uptake reported in these studies are very low compared to those typically measured in soft‐bodied marine invertebrates, suggesting that integumental uptake of nutrients is probably not significant in freshwater animals (364).…”