Transepidermal uptake of the amino acid leucine by freshwater triclads

Ontogenetic patterns and phylogenetic trends in freshwater flatworms (Tricladida); constraint or selection?

“…Nevertheless, preliminary observations on the uptake and loss of labelled amino acids (following the techniques of Read, 1981, and do suggest a marked reduction in the protein turnover of adults as compared with juvenile D. lacteum but no difference between the same age categories of P tenuis (Calow, unpubl. ) .…”

Ontogenetic patterns and phylogenetic trends in freshwater flatworms (Tricladida); constraint or selection?

“…Nevertheless, preliminary observations on the uptake and loss of labelled amino acids (following the techniques of Read, 1981, and do suggest a marked reduction in the protein turnover of adults as compared with juvenile D. lacteum but no difference between the same age categories of P tenuis (Calow, unpubl. ) .…”

Biology of the Integument

“…However, it appears from the context in which integumental amino acid transport phenomena are usually treated in the literature, that most authors implicitly consider the external face of the integument as the main barrier governing the exchange of amino acids between animal and environment. As a rule, workers in this field have presented time-course curves for amino acid uptake showing little or no evidence of significant intercepts (but see Calow and Read 1981), a fact which either negates the generality of the above interpretation, or could possibly be due to a different choice as to incubation and rinsing times. ), using the same carefully standardized techniques in studying epidermal L-alanine uptake by N. diversicolor as described above for monosaccharide transport, reported that time-course intercepts turned out positively correlated with the slopes of the time-~ourse curves.…”

Ontogenetic patterns and phylogenetic trends in freshwater flatworms (Tricladida); constraint or selection?

“…Nevertheless, preliminary observations on the uptake and loss of labelled amino acids (following the techniques of Read, 1981, and do suggest a marked reduction in the protein turnover of adults as compared with juvenile D. lacteum but no difference between the same age categories of P tenuis (Calow, unpubl. ) .…”

Biology of the Integument

“…However, it appears from the context in which integumental amino acid transport phenomena are usually treated in the literature, that most authors implicitly consider the external face of the integument as the main barrier governing the exchange of amino acids between animal and environment. As a rule, workers in this field have presented time-course curves for amino acid uptake showing little or no evidence of significant intercepts (but see Calow and Read 1981), a fact which either negates the generality of the above interpretation, or could possibly be due to a different choice as to incubation and rinsing times. ), using the same carefully standardized techniques in studying epidermal L-alanine uptake by N. diversicolor as described above for monosaccharide transport, reported that time-course intercepts turned out positively correlated with the slopes of the time-~ourse curves.…”

Ontogenetic patterns and phylogenetic trends in freshwater flatworms (Tricladida); constraint or selection?

“…Nevertheless, preliminary observations on the uptake and loss of labelled amino acids (following the techniques of Read, 1981, and do suggest a marked reduction in the protein turnover of adults as compared with juvenile D. lacteum but no difference between the same age categories of P tenuis (Calow, unpubl. ) .…”

Biology of the Integument

“…However, it appears from the context in which integumental amino acid transport phenomena are usually treated in the literature, that most authors implicitly consider the external face of the integument as the main barrier governing the exchange of amino acids between animal and environment. As a rule, workers in this field have presented time-course curves for amino acid uptake showing little or no evidence of significant intercepts (but see Calow and Read 1981), a fact which either negates the generality of the above interpretation, or could possibly be due to a different choice as to incubation and rinsing times. ), using the same carefully standardized techniques in studying epidermal L-alanine uptake by N. diversicolor as described above for monosaccharide transport, reported that time-course intercepts turned out positively correlated with the slopes of the time-~ourse curves.…”