Tadashi Andoh - Academia.edu (original) (raw)

Papers by Tadashi Andoh

Research paper thumbnail of Purification and Structural Determination of Insulins, Glucagons and Somatostatin from Stone Flounder, Kareius bicoloratus

Zoological Science, 1998

Early stationary phase culture supernatants of Streptomyces coelicolor A3(2) contained at least f... more Early stationary phase culture supernatants of Streptomyces coelicolor A3(2) contained at least four small diffusible signaling molecules that could elicit precocious antibiotic synthesis in the producing strain. The compounds were not detected in exponentially growing cultures. One of these compounds, SCB1, was purified to homogeneity and shown to be a ␥-butyrolactone of structure (2R,3R,1R)-2-(1-hydroxy-6-methylheptyl)-3hydroxymethylbutanolide. Bioassays of chemically synthesized SCB1, and of its purified stereoisomers, suggest that SCB1 acts in a highly specific manner to elicit the production of both actinorhodin and undecylprodigiosin, the two pigmented antibiotics made by S. coelicolor.

Research paper thumbnail of Molecular and functional characterization of opsins in barfin flounder (Verasper moseri)

Gene, Jan 10, 2015

Green light irradiation facilitates the somatic growth of barfin flounder (Verasper moseri). Howe... more Green light irradiation facilitates the somatic growth of barfin flounder (Verasper moseri). However, the V. moseri visual system, which may be associated with somatic growth by acting on the endocrine system upon exposure to this particular wavelength, remains largely unexplored. Herein, we characterized the visual opsin repertoire of V. moseri to understand the molecular basis underlying this effect. The five types of visual opsins that are found in vertebrates were cloned from RNA that was extracted from the eyes of V. moseri. Notably, V. moseri possessed one pseudogene (RH2-A) and two intact (RH2-B and RH2-C) copies of "green-sensitive" opsin genes. The wavelengths of maximum absorption spectra (λmax) for each of the reconstituted photopigments were 552nm for "red-sensitive" LWS, 506nm for RH2-B, 490nm for RH2-C, 482nm and 416nm for "blue-sensitive" SWS2A and SWS2B, respectively, 367nm for "ultraviolet-sensitive" SWS1, and 494nm for "...

Research paper thumbnail of Two Molecular Forms of Insulin from Barfin Flounder, Verasper moseri, are Derived from a Single Gene

Zoological Science, 1998

... 1981. The effect of prolonged administration of bovine insulin in rainbow trout (Salmo gairdn... more ... 1981. The effect of prolonged administration of bovine insulin in rainbow trout (Salmo gairdneri R.). Gen Comp Endocrinol 43:211–217. CrossRef, PubMed. Andoh, T. and H. Nagasawa. 1997. ... CrossRef, PubMed, CSA. Conlon, JM, R. Goke, PC Andrews, and L. Thim. 1989. ...

Research paper thumbnail of The use of poly-L-lysine to facilitate examination of sperm entry into pelagic, non-adhesive fish eggs

The International Journal of Developmental Biology, 2008

The fish egg is surrounded by a thick envelope called the chorion. The fertilizing spermatozoon e... more The fish egg is surrounded by a thick envelope called the chorion. The fertilizing spermatozoon enters the egg through a canal-like structure in the chorion, the micropyle. Examination of micropyle at fertilization is difficult if eggs are large and have no distinct landmarks surrounding the micropyle, or if they are positively buoyant in water. Eggs of many commercially important fishes (e.g., flounder, sea bream and eel) are buoyant in water or only slightly adhere to solid objects (e.g., sands, rock and water plants), which makes observation of spermatozoa at fertilization difficult. Here, we report that such eggs can be firmly attached to plastic and glass dishes that have been previously coated with poly-L-lysine. These adhering eggs can be fertilized and develop normally on the dishes. Observations of micropyles of three fish species, before and after sperm entry are presented.

Research paper thumbnail of Multiple molecular forms of glucagon and insulin in the kaluga sturgeon, Huso dauricus

Peptides, 2000

Five molecular forms of glucagon and two molecular forms of insulin were characterized from the k... more Five molecular forms of glucagon and two molecular forms of insulin were characterized from the kaluga sturgeon. Substitutions occurred at two to thirteen internal amino acid residues among the five molecular forms of glucagons, indicating that these glucagons were encoded by five distinct genes. The amino acid sequences of two insulins from the kaluga sturgeon were identical to those of paddlefish insulin-II and Russian sturgeon insulin except that kaluga sturgeon insulin-I had an extension of five residues at the B-chain N-terminus. This is the first demonstration that more than two molecular forms of glucagon have been characterized from a single animal species.

Research paper thumbnail of Amino acids are more important insulinotropins than glucose in a teleost fish, barfin flounder (Verasper moseri)

General and Comparative Endocrinology, 2007

The insulinotropic effects of eighteen L-amino acids, two D-amino acids, and glucose were investi... more The insulinotropic effects of eighteen L-amino acids, two D-amino acids, and glucose were investigated to evaluate the priority of those as stimulators of insulin secretion in barfin flounder (Verasper moseri). This is also the first step in characterizing the insulinotropin-sensing molecule. After intramuscular injection of amino acids or glucose at doses of 3.50 and 1.75 mmol/kg body weight, plasma was collected periodically to determine plasma insulin level. Twelve amino acids and glucose showed insulinotropic effects. Four L-amino acids (Arg, Ala, Met, Ser) produced significantly higher integrated levels of plasma insulin (12.4-34.8 ng/ml) than glucose (average: 4.7 ng/ml) during 3h after injection. D-Amino acids (Arg, Ala) showed no activity. This indicates that many amino acids have strong insulinotropic activities and supports a classic idea, which is well known but has not been confirmed, that amino acids rather than glucose are the important insulinotropins in fish. This study also indicates that the insulinotropic activity of amino acids is restricted to L-amino acids and establishes which amino acids are the strongest stimulators of the insulinotropin sensor in barfin flounder. Co-injection of insulin and L-Thr, L-Ala, or glucose produced a hypoglycemic and hypoaminoacidemic state, indicating that insulin can lower blood amino acid level as well as blood sugar level. This study suggests that insulin plays a more important role than glucose in the regulation of blood L-amino acid metabolism, at least in flounder.

Research paper thumbnail of Development of a Time-Resolved Fluoroimmunoassay for Insulins and Its Application to Monitoring of Insulin Secretion Induced by Feeding in the Barfin Flounder, Verasper moseri

General and Comparative Endocrinology, 2002

Time-resolved fluoroimmunoassay Rapid diagnosis s u m m a r y

Research paper thumbnail of Purification and Structural Determination of Insulins, Glucagons and Somatostatin from Stone Flounder, Kareius bicoloratus

Zoological Science, 1998

Early stationary phase culture supernatants of Streptomyces coelicolor A3(2) contained at least f... more Early stationary phase culture supernatants of Streptomyces coelicolor A3(2) contained at least four small diffusible signaling molecules that could elicit precocious antibiotic synthesis in the producing strain. The compounds were not detected in exponentially growing cultures. One of these compounds, SCB1, was purified to homogeneity and shown to be a ␥-butyrolactone of structure (2R,3R,1R)-2-(1-hydroxy-6-methylheptyl)-3hydroxymethylbutanolide. Bioassays of chemically synthesized SCB1, and of its purified stereoisomers, suggest that SCB1 acts in a highly specific manner to elicit the production of both actinorhodin and undecylprodigiosin, the two pigmented antibiotics made by S. coelicolor.

Research paper thumbnail of Molecular and functional characterization of opsins in barfin flounder (Verasper moseri)

Gene, Jan 10, 2015

Green light irradiation facilitates the somatic growth of barfin flounder (Verasper moseri). Howe... more Green light irradiation facilitates the somatic growth of barfin flounder (Verasper moseri). However, the V. moseri visual system, which may be associated with somatic growth by acting on the endocrine system upon exposure to this particular wavelength, remains largely unexplored. Herein, we characterized the visual opsin repertoire of V. moseri to understand the molecular basis underlying this effect. The five types of visual opsins that are found in vertebrates were cloned from RNA that was extracted from the eyes of V. moseri. Notably, V. moseri possessed one pseudogene (RH2-A) and two intact (RH2-B and RH2-C) copies of "green-sensitive" opsin genes. The wavelengths of maximum absorption spectra (λmax) for each of the reconstituted photopigments were 552nm for "red-sensitive" LWS, 506nm for RH2-B, 490nm for RH2-C, 482nm and 416nm for "blue-sensitive" SWS2A and SWS2B, respectively, 367nm for "ultraviolet-sensitive" SWS1, and 494nm for "...

Research paper thumbnail of Two Molecular Forms of Insulin from Barfin Flounder, Verasper moseri, are Derived from a Single Gene

Zoological Science, 1998

... 1981. The effect of prolonged administration of bovine insulin in rainbow trout (Salmo gairdn... more ... 1981. The effect of prolonged administration of bovine insulin in rainbow trout (Salmo gairdneri R.). Gen Comp Endocrinol 43:211–217. CrossRef, PubMed. Andoh, T. and H. Nagasawa. 1997. ... CrossRef, PubMed, CSA. Conlon, JM, R. Goke, PC Andrews, and L. Thim. 1989. ...

Research paper thumbnail of The use of poly-L-lysine to facilitate examination of sperm entry into pelagic, non-adhesive fish eggs

The International Journal of Developmental Biology, 2008

The fish egg is surrounded by a thick envelope called the chorion. The fertilizing spermatozoon e... more The fish egg is surrounded by a thick envelope called the chorion. The fertilizing spermatozoon enters the egg through a canal-like structure in the chorion, the micropyle. Examination of micropyle at fertilization is difficult if eggs are large and have no distinct landmarks surrounding the micropyle, or if they are positively buoyant in water. Eggs of many commercially important fishes (e.g., flounder, sea bream and eel) are buoyant in water or only slightly adhere to solid objects (e.g., sands, rock and water plants), which makes observation of spermatozoa at fertilization difficult. Here, we report that such eggs can be firmly attached to plastic and glass dishes that have been previously coated with poly-L-lysine. These adhering eggs can be fertilized and develop normally on the dishes. Observations of micropyles of three fish species, before and after sperm entry are presented.

Research paper thumbnail of Multiple molecular forms of glucagon and insulin in the kaluga sturgeon, Huso dauricus

Peptides, 2000

Five molecular forms of glucagon and two molecular forms of insulin were characterized from the k... more Five molecular forms of glucagon and two molecular forms of insulin were characterized from the kaluga sturgeon. Substitutions occurred at two to thirteen internal amino acid residues among the five molecular forms of glucagons, indicating that these glucagons were encoded by five distinct genes. The amino acid sequences of two insulins from the kaluga sturgeon were identical to those of paddlefish insulin-II and Russian sturgeon insulin except that kaluga sturgeon insulin-I had an extension of five residues at the B-chain N-terminus. This is the first demonstration that more than two molecular forms of glucagon have been characterized from a single animal species.

Research paper thumbnail of Amino acids are more important insulinotropins than glucose in a teleost fish, barfin flounder (Verasper moseri)

General and Comparative Endocrinology, 2007

The insulinotropic effects of eighteen L-amino acids, two D-amino acids, and glucose were investi... more The insulinotropic effects of eighteen L-amino acids, two D-amino acids, and glucose were investigated to evaluate the priority of those as stimulators of insulin secretion in barfin flounder (Verasper moseri). This is also the first step in characterizing the insulinotropin-sensing molecule. After intramuscular injection of amino acids or glucose at doses of 3.50 and 1.75 mmol/kg body weight, plasma was collected periodically to determine plasma insulin level. Twelve amino acids and glucose showed insulinotropic effects. Four L-amino acids (Arg, Ala, Met, Ser) produced significantly higher integrated levels of plasma insulin (12.4-34.8 ng/ml) than glucose (average: 4.7 ng/ml) during 3h after injection. D-Amino acids (Arg, Ala) showed no activity. This indicates that many amino acids have strong insulinotropic activities and supports a classic idea, which is well known but has not been confirmed, that amino acids rather than glucose are the important insulinotropins in fish. This study also indicates that the insulinotropic activity of amino acids is restricted to L-amino acids and establishes which amino acids are the strongest stimulators of the insulinotropin sensor in barfin flounder. Co-injection of insulin and L-Thr, L-Ala, or glucose produced a hypoglycemic and hypoaminoacidemic state, indicating that insulin can lower blood amino acid level as well as blood sugar level. This study suggests that insulin plays a more important role than glucose in the regulation of blood L-amino acid metabolism, at least in flounder.

Research paper thumbnail of Development of a Time-Resolved Fluoroimmunoassay for Insulins and Its Application to Monitoring of Insulin Secretion Induced by Feeding in the Barfin Flounder, Verasper moseri

General and Comparative Endocrinology, 2002

Time-resolved fluoroimmunoassay Rapid diagnosis s u m m a r y