Search PubMed⌕ Search

Biomedical subjects

T Hayashida

Publications and source records attributed to T Hayashida.

At least 91 records · Page 5Linked to original sources

Human somatotropin: biological characterization of the recombinant molecule.

The recombinant hormone obtained by non-covalent interaction of the NH2-terminal 134 amino acid fragment with the COOH-terminal 51 amino acid fragment of the reduced-carbamidomethylated human somatotropin molecule is found to exhibit nearly full biological activity of the native hormone, as evidenced by the stimulation of hepatic ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) in vivo and protein synthesis in mouse mammary gland in vitro. Radioimmunoassay data indicate that the recombinant behaves immunochemically in a manner almost identical to that of the native hormone.

Amino Acid Sequence↗

Purification and properties of reptilian and amphibian growth hormones.

Highly purified growth hormone was isolated from the pituitaries of two reptilian species, the snapping turtle and the sea turtle, and two amphibian species, the bullfrog and the leopard frog. Characterization studies were performed with these growth hormones in comparison with mammalian and avian growth hormones. Great similarities among these species were found in chromatographic behavior, Ve/Vo ratios (2.0) on gel filtration, disc electrophoretic patterns, terminal amino acid residues and immunochemical reactivity with snapping turtle growth hormone antiserum. Species differences were noted in amino acid composition and immunoactivity measured by rat growth hormone antiserum, and these appeared to reflect the phylogenetic relationships among the four tetrapod species. The turtle and frog growth hormones gave parallel dose responses in the rat tibia assay. All were less potent than the bovine growth hormone standard except the bullfrog growth hormone which was equipotent if not more active. The data indicate that many elements of growth hormone structure have been strongly conserved during evolution.

Amino Acid Sequence↗

Pituitary growth hormones: further evidence for evolutionary conservatism based on immunochemical studies.

Immunochemical relatedness of preparations of purified somatotropins (growth hormones) of somatotropins in pituitary extracts from various vertebrate species was investigated by applying an antiserum to a purified somatotropin from a submammalian species, the snapping turtle. With the exception of monkey somatotropin, all mammalian, reptilian, and avian preparations tested showed reactions of identity or near identity by immunodiffusion studies in agar gel. Radioimmunoassay employing labeled rat somatotropin as a tracer and for standards, revealed that these same pituitary preparations gave steep inhibition slopes that were parallel or nearly parallel to each other. Purified somatotropins or somatotropins in pituitary extracts of subreptilian species, including an amphibian and existing primitive fishes, showed partial yet substantial relatedness to mammalian (ray) or reptilian (turtle) somatotropins by both immunodiffusion and radioimmunoassay. Our evidence indicates that the immunochemical relatedness of somatotropins from various vertebrate species appears to be even closer than has been suggested previously, and that a high degree of conservation of structure occurs during evolution.

Animals↗

Amphibian pituitary growth hormone and prolactin: immunochemical relatedness to rat growth hormone.

Growth hormone and prolactin were electrophoretically isolated from amphibian pituitaries and then were tested in a radioimmunoassay with labeled rat growth hormone and antiserum to the same hormone. This isolation and purification of the hormones increased the steepness of the slopes of competitive inhibition in this system when compared to those of crude extracts. Both hormones from most species tested showed high immunochemical cross-reactivity, indicating that amphibian growth hormone and prolactin are structurally related to rat growth hormone.

Ambystoma↗

[Colonic syndrome].

Explore the source record for details and available documents.

Colonic Diseases↗

Prolactin localization in the primate pituitary by immunofluorescence.

Cells which contain prolactin were clearly distinguished from those which contain growth hormone in adult monkey pituitary glands by means of histologic and fluorescent antibody techniques. The results indicate that in primates, as well as in other mammals, prolactin is immunochemically distinguishable from growth homone.

Animals↗