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H Kawauchi

Publications and source records attributed to H Kawauchi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Growth regulation by insulin-like growth factor-I in fish.

Insulin-like growth factor-I (IGF-I) is a mitogenic polypeptide that plays an essential role in the regulation of development and somatic growth of vertebrates, mainly by mediating growth hormone actions. It has clearly been established that the structure of IGF-I and its biological function has been highly conserved among vertebrates. In this paper, we review the recent developments in the molecular, biochemical, and physiological properties of IGF-I in fish.

Amino Acid Sequence↗
PubMed1999

The duality of fish gonadotropin receptors: cloning and functional characterization of a second gonadotropin receptor cDNA expressed in the ovary and testis of amago salmon (Oncorhynchus rhodurus).

We previously isolated a cDNA encoding a gonadotropin receptor (sGTH-R) from amago salmon (Oncorhynchus rhodurus) ovarian follicles. In the present study, we cloned a second gonadotropin receptor (sGTH-RI) from the same RNA preparations. Overall sequence homology between sGTH-RI and sGTH-R is 44%. The highest homology occurs with mammalian FSH receptors (49%). Functional characterization examined in COS-7 cells transiently transfected with sGTH-RI showed the largest increase in cAMP production when exposed to salmon GTH I. These results provide the first evidence in any ectothermic vertebrate, the amago salmon, of the duality of gonadotropin receptors.

Amino Acid Sequence↗
PubMed1999

Cloning, functional characterization, and expression of a gonadotropin receptor cDNA in the ovary and testis of amago salmon (Oncorhynchus rhodurus).

A gonadotropin receptor was cloned from amago salmon (Oncorhynchus rhodurus) ovarian follicles. This receptor (sGTH-R) belongs to the glycoprotein hormone receptor family with a large extracellular and seven-transmembrane domains. Its sequence homology is highest with mammalian LH receptors. Phylogenetic analysis reveals that sGTH-R is grouped with mammalian and chicken FSH and LH receptors, but not with mammalian TSH receptors. sGTH-R is expressed dominantly in the ovary and testis. Functional characterization examined with transiently transfected mammalian cells revealed increased intracellular cAMP level when exposed to mammalian and fish gonadotropins; the most potent hormone was salmon GTH II. These results indicate that the cloned cDNA encodes a functional amago salmon GTH receptor protein.

Amino Acid Sequence↗
PubMed1999

Assignment of disulfide linkages in chum salmon stanniocalcin.

Stanniocalcin (STC) is a hypocalcemic glycoprotein hormone secreted by the corpuscles of Stannius, endocrine glands unique to the bony fishes. Recently, two cDNAs encoding proteins, STC-1 and STC-2, homologous to fish STC have been identified in humans and rodents. The STC-1, but not STC-2, is identical to fish STC with respect to location of all Cys residues. The present study reports the localization of inter- and intra-molecular disulfide linkages in chum salmon STC. The chum salmon STC was deglycosylated and digested with several proteases in series. Six fragments, each of which consisted of two peptides connected by a single disulfide bond, were isolated by HPLC. Disulfide bonds were determined by sequence analysis after reduction and S-alkylation of each peptide fragment. Chum salmon STC is a homodimer connected by a single intermonomeric disulfide bond at Cys169. The monomer consists of 179 amino-acids, containing five intramonomeric disulfide bonds formed between Cys12-Cys26, Cys21-Cys41, Cys32-Cys81, Cys65-Cys95, and Cys102-Cys137.

Amino Acid Sequence↗
PubMed1999

Possible gonadotropin cells in the lamprey pituitary: colocalization of mammalian LH-like immunoreactivity and glycoconjugate in adult sea lampreys (Petromyzon marinus).

In lampreys, although gonadotropin (GTH) has not yet been isolated from the pituitary gland, the presence of GTH has been strongly suggested. To detect possible GTH in the sea lamprey (Petromyzon marinus) pituitary, two different cytochemical probes were tested: One was the use of antibodies to GTHs, and the other was the use of lectin-screening kits for demonstration of glycoconjugate in hormonal molecules. GTH-like immunoreactivity was found in cells distributed in the ventral half of the proximal pars distalis. These cells were stained intensely by all four lots of anti-ovine LH including LHbeta, and were stained moderately or weakly by several other antibodies to LH-related GTHs, such as human LHbeta, hCGbeta, amphibian LH, and sturgeon GTH IIbeta. On the other hand, there were no positive reactions in the sea lamprey pituitary using the antibodies to FSH-related GTHs, thyrotropin (TSH), or pituitary glycoprotein hormones of teleost origin. Thus, GTH-like material in the sea lamprey pituitary seems to be more closely related to mammalian-like LH, rather than to FSH or TSH, as far as immunocytochemical determinants. A total of 21 kinds of lectins was tested. Among those, GTH-positive cells were also stained positively by concanavalin A and Vicia villosa agglutinin. Thus, the present study demonstrates colocalization of LH-like immunoreactivity and glycoconjugate in cells in the ventral half of the proximal pars distalis of the sea lamprey pituitary. It is suggested that those cells are most likely to be GTH cells in the sea lamprey pituitary.

Animals↗
PubMed1999

Somatolactin in the white sturgeon and African lungfish and its evolutionary significance.

Somatolactin (SL) is a newly characterized pituitary hormone belonging to the growth hormone-prolactin family. Until now SL has been identified only in teleosts, the most highly derived ray-finned fishes. We report here the cloning of SL cDNAs from two species of bony fish, the white sturgeon (Acipenser transmontanus) and the African lungfish (Protopterus annectens). Overlapping partial cDNA clones corresponding to teleost SLs were amplified by polymerase chain reaction (PCR) from either single-strand or double-strand cDNA from pituitary glands. Excluding the poly(A) tail, the sturgeon SL cDNA is 881 base pairs (bp). This is comparable to 1.0 kb estimated by Northern blot analysis. It contains a 696-bp open reading frame encoding a prehormone of 232 amino acids (aa) with a signal peptide of 24 aa and a mature protein of 208 aa. Excluding the poly(A) tail, the lungfish SL cDNA is 938 bp. This is comparable to 1.1 kb estimated by Northern blot analysis. It contains a 696-bp open reading frame encoding a prehormone of 232 aa with a signal peptide of 26 aa and a mature protein of 206 aa. The deduced aa sequences of sturgeon and lungfish SLs show 76-60% and 65-54% identity with teleost SLs, respectively. These values are significantly higher than the 30% identity with nonteleostean growth hormones and prolactins. Immunostaining of sturgeon pituitary with anti-salmon SL serum demonstrated that the SL cells were localized in the pars intermedia, as in teleosts. The present results demonstrate that the SL gene is present in two divergent lineages, the Actinopterygii (Chondrostei: white sturgeon) and the Sarcopterygii (Dipnoi: African lungfish).

Amino Acid Sequence↗
PubMed1999

A newly characterized melanotropin in proopiomelanocortin in pituitaries of an elasmobranch, Squalus acanthias.

Proopiomelanocortin (POMC) is a precursor for corticotropin (ACTH), three or fewer molecular types of melanotropin (MSH), and beta-endorphin. This protein is thought to have evolved by duplication of MSH genomic segments. Here we report that the POMC in the dogfish, an elasmobranch, contains a fourth type of MSH in addition to classical alpha-, beta-, and gamma-MSH. POMC cDNA was amplified by PCR from double-strand cDNA prepared from dogfish pituitary and ligated into lambdaZAP II. The POMC cDNA is composed of 1315 bp without a poly(A) tail. Northern blot analysis detected a 1.4-kb signal of dogfish POMC mRNA. An open reading frame of the POMC cDNA encodes 320 amino acids, including a signal peptide of 26 amino acids. The dogfish POMC includes gamma-MSH, ACTH, alpha-MSH, beta-MSH, and beta-endorphin at positions 50-61, 115-153, 115-127, 239-256, and 259-294, respectively. In addition to these classical peptides, a newly discovered MSH, which we have termed delta-MSH, is present in dogfish POMC at position (184-195). The four dogfish MSHs can be separated into two groups based on their sequence identities: one pair consists of alpha-MSH and gamma-MSH, and the other consists of beta-MSH and delta-MSH, suggesting that gamma-MSH and delta-MSH may have been duplicated evolutionarily from alpha-MSH and beta-MSH, respectively. gamma-MSH might first have appeared in early gnathostomes because it is absent in the most primitive vertebrate group, the agnathans. delta-MSH, which at this time is found only in chondrichthians, might have appeared after the divergence of chondrichthians from a lineage leading to osteichthyans and tetrapods.

Amino Acid Sequence↗
PubMed1999

Isolation and cDNA cloning of somatolactin in rabbitfish (Siganus guttatus).

We report the isolation and cDNA cloning of somatolactin (SL) from rabbitfish, Siganus guttatus. Rabbitfish SL was isolated from an alkaline extract of the pituitary glands by gel filtration chromatography on Sephadex G-100 and reversed-phase high-performance liquid chromatography. SL was monitored by immunoblotting with flounder SL antiserum. The preparation (yield: 0.86 mg/g wet tissues) contained two immunoreactive bands of 24 and 28 kDa on SDS-PAGE. Overlapping partial cDNA clones corresponding to teleost SLs were amplified by PCR from single-strand cDNA from pituitary glands. Excluding the poly(A) tail, rabbitfish SL cDNA is 1605 bp long. It contains a 693-bp open reading frame encoding a signal peptide of 24 amino acids (aa) and a mature protein of 207 aa. Rabbitfish SL has two possible N-glycosylation sites at positions 11 and 121 and seven half Cys residues. The deduced amino acid sequence shows over 80% identity with those of advanced teleosts like sea bream, red drum, and flounder, 76% with the salmonids, 57% with the eel, and 46% with the goldfish SL.

Amino Acid Sequence↗
PubMed1999

Molecular cloning of lungfish proopiomelanocortin cDNA.

To investigate the evolution of proopiomelanocortin (POMC) from fish to tetrapods, nucleotide sequence of POMC cDNA from a lobe-finned fish, the African lungfish, was determined. POMC cDNA was prepared from lungfish pituitary glands. The POMC cDNA is composed of 1114 bp, excluding a poly-A tail, and encodes 255 amino acids (aa) including a signal peptide of 25 aa. The lungfish POMC contains the segment corresponding to gamma-melanotropin (MSH), corticotropin, alpha-MSH, beta-MSH, and beta-endorphin at positions (50-61), (108-146), (108-120), (178-194), and (197-230), respectively. The lungfish POMC shows greater sequence identity on average with amphibian (62%), ancient ray-finned fishes including acipenseriformes and semionotiformes (62%), and mammalian POMC (52%) than with teleostean (49%), elasmobranch (46%), and agnathan POMC (31%). Thus, the overall structural feature of lungfish POMC is close to the tetrapod POMCs which contain gamma-MSH and the ancient ray-finned fishes POMCs containing gamma-MSH-like sequence. However, amino acid sequence of lungfish beta-endorphin exhibits properties which are specifically observed in the ray-finned fishes and the elasmobranchs.

Adrenocorticotropic Hormone↗
PubMed1999

Apoptosis during inner ear development in human and mouse embryos: an analysis by computer-assisted three-dimensional reconstruction.

Apoptosis in the developing inner ear tissue of human (Carnegie stage 14 to 21, approximately 5 to 8 weeks of gestation) and mouse (10.5 to 14 days of gestation) embryos was systematically analyzed by a computer-assisted three-dimensional reconstruction of the serial histological sections and by the TUNEL method. Morphogenetic events such as folding between the utricular portion and endolymphatic duct, constriction of the junction of the saccule with the cochlea and folding of the vestibular portion to form the semicircular ducts were accompanied by a localized distribution of apoptosis. The apoptosis was also related to the innervation of the cochlear and vestibular epithelia from the sensory ganglion of the eighth cranial nerve and the differentiation of the otic epithelia into the sensory epithelia. These results suggest that apoptosis plays an important role in the development of the inner ear.

Animals↗
PubMed1999

Clinical efficacy of an antiallergic drug on otitis media with effusion in association with allergic rhinitis.

OBJECTIVE: The effect of azelastine hydrochloride (AZ), an oral antiallergic drug, was evaluated in patients displaying otitis media with effusion (OME) accompanying allergic rhinitis. METHODS: A total of 53 patients diagnosed with OME accompanied by symptomatic perennial allergic rhinitis were randomized to receive in an open fashion 2 mg of AZ in combination with 750 mg of S-carboxymethyl cysteine (SCMC) per day, or 750 mg of SCMC only (controls) for 8 weeks. Efficacy was assessed according to the global improvement rating (GIR) of six nasal or four ear symptoms or signs. RESULTS: Patients treated with AZ and SCMC had superior improvements in their nasal symptom GIRs compared to controls overall across the 8 week trial, but not in their ear symptom GIRs. However, the clinical course of patients treated with AZ and SCMC tended to be better than that of patients treated with SCMC only, and the nasal and ear symptom GIRs were significantly correlated in the AZ-treated group. CONCLUSION: These data suggest that AZ may not provide direct efficacy on the ear symptoms in OME patients with allergic rhinitis, but that there might be a possibility of its indirect efficacy in the patients in part by relieving the allergic rhinitis.

Administration, Oral↗
PubMed1999

The modulating effects of proinflammatory cytokines interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), and immunoregulating cytokines IL-10 and transforming growth factor-beta (TGF-beta), on anti-microbial activity of murine peritoneal macrophages against Mycobacterium avium-intracellulare complex.

We assessed the roles of proinflammatory cytokines IFN-gamma and TNF-alpha, and immunoregulatory cytokines IL-10 and TGF-beta in the modulation of the anti-microbial activity of murine peritoneal macrophages against Mycobacterium avium-intracellulare complex (MAIC). First, both IFN-gamma and TNF-alpha significantly reduced the bacterial growth in macrophages, indicating that these cytokines participate in up-regulation of macrophage anti-MAIC function. Second, although MAIC-infected macrophages produced substantial amounts of IL-10 and TGF-beta, neutralization of endogenous IL-10 and TGF-beta with anti-IL-10 and anti-TGF-beta antibodies, respectively, did not affect the intracellular growth of MAIC in macrophages from mice with BcgS (MAIC-susceptible) or BcgI (MAIC-resistant) genotype, regardless of the virulence of test MAIC strains. The same result was also obtained for macrophages stimulated with IFN-gamma or TNF-alpha. Third, in MAIC-infected mice, the growth of organisms at the sites of infection (lungs and spleens) was not affected by administration of anti-IL-10 or anti-TGF-beta antibodies. These findings indicate that, in the case of mice, endogenous IL-10 and TGF-beta are essentially ineffective in down-regulating macrophage anti-MAIC functions not only in vitro but also in vivo.

Adjuvants, Immunologic↗
PubMed1999

Therapeutic effects of benzoxazinorifamycin KRM-1648 administered alone or in combination with a half-sized secretory leukocyte protease inhibitor or the nonsteroidal anti-inflammatory drug diclofenac sodium against Mycobacterium avium complex infection in mice.

The effects of half-sized secretory leukocyte protease inhibitor or diclofenac sodium administered alone or in combination with the benzoxazinorifamycin KRM-1648 on the therapeutic efficacy of KRM-1648 against Mycobacterium avium complex (MAC) in mice were studied. Neither of the two anti-inflammatory drugs affected the efficacy of KRM-1648, while they exerted significant modulating effects on tumor necrosis factor alpha production by MAC-infected macrophages.

Animals↗
PubMed1999

Efficacy of an antiallergic drug on otitis media with effusion in association with allergic rhinitis. An experimental study.

The effect of an antiallergic drug on the evacuation of middle ear effusion (MEE) from the tubotympanum was investigated by means of an animal model with both otitis media with effusion (OME) and allergic rhinitis. Azelastine hydrochloride (AZ), an oral antiallergic drug, was administered and the presence of MEE was investigated. Serous MEE was seen in 12 of the 13 untreated control animals on the 11th day after the experimental OME was induced, whereas MEE was detected in 9 of the 13 animals administered 1 mg/kg of AZ, but only in 4 of the 13 animals administered 2 mg/kg of AZ. In addition, the effect of AZ on MEE production was also examined in an experimental OME animal model without allergic rhinitis. Middle ear effusion was observed in all OME animals that received 2 mg/kg AZ for 5 consecutive days, before and 3 days after the experimental OME was induced. Results of the present study indicate that AZ promotes the evacuation of MEE from the tubotympanum in the OME animal model associated with nasal allergy. These data suggest that an antiallergic drug may contribute to the therapy of OME patients in association with nasal allergy indirectly, by promoting evacuation of MEE due to inhibition of type I allergic reactions in the nasopharynx.

Animals↗
PubMed1998

Conjugation of ubiquitin-like polypeptide to intracellular acceptor proteins.

Monoclonal nonspecific suppressor factor (MNSF), a lymphokine produced by a murine hybridoma, was originally found to inhibit the generation of LPS-induced immunoglobulin secreting cells. MNSF comprises of MNSF beta, an isoform of MNSF, and the other isoform, MNSF alpha. Ubiquitin-like segment (Ubi-L) of MNSF beta shows MNSF-like activity. Ubi-L (7.8 kDa) has 36% homology with 8.5 kDa ubiquitin. GST-Ubi-L was labeled with 125I by the chloramine T method and tested for its conjugation to acceptor in splenocyte lysates. 125I-GST-Ubi-L conjugation on SDS-PAGE showed heterogeneous bands including 95 kDa GST-Ubi-L conjugation in the splenocyte, but not reticulocyte lysates. The Ubi-L adduct appeared to be MNSF-related molecule because anti-MNSF monoclonal antibody (mAb) recognized the 95 kDa band. The pattern of the conjugations was different from that seen in ubiquitination. Unlabeled GST-Ubi-L inhibited the conjugations, while ubiquitin did not. alpha-Lactalbumin, one of the target proteins for ubiquitination, failed to conjugate to GST-Ubi-L. In addition, covalent conjugation of ubiquitin to reticulocyte lysates was also interfered by GST-Ubi-L. These results suggest that Ubi-L may conjugate to acceptor proteins in a similar, but not in the same way as ubiquitination, and might play an important role in lymphoid cells.

Animals↗
PubMed1998

Spatial and temporal distribution of proopiomelanotropin and proopiocortin mRNA during the life cycle of the sea lamprey: a qualitative and quantitative in situ hybridization study.

Two POMC-like pituitary prohormones proopiocortin (POC) and proopiomelanotropin (POM) have been characterized from adult sea lampreys (Petromyzon marinus). POC encodes a nasohypophysial factor (NHF), ACTH, an MSH, and beta-END; and POM encodes MSH-A, MSH-B, and beta-END. Two radiolabeled riboprobes, one encoding a unique portion of POC mRNA and the other encoding the MSH-B domain unique to POM mRNA, were generated in order to examine the expression of POC and POM during the life cycle of the sea lamprey by in situ hybridization. POC expression appears evenly distributed throughout most cells of the rostral pars distalis (RPD) during the entire life cycle. POC expression also occurs in scattered cells of the caudal (proximal) pars distalis (CPD) at stage 5 of metamorphosis. By the prespawner period, POC expression is mainly distributed in the dorsal aspect of this region. POM expression was completely confined to most cells of the pars intermedia (PI) at all periods examined. Quantitative, computer-assisted, image analysis of POM expression revealed high signal densities in all larvae which decreased by early metamorphosis, steadily increased and reached high levels by late metamorphosis (stages 6 and 7), and attained even higher levels in prespawners. Volumetric analysis revealed that the net volume of POM expressing cells is at its lowest in larvae and increases during subsequent development. Analysis of signal density and volumetric measurements of POC expression revealed that POC expression in the RPD is low in larvae and steadily increases during subsequent intervals of the life cycle reaching very high levels by the prespawning period. POC expression in the CPD, first visible at stage 5, increases steadily throughout the remainder of metamorphosis and reaches the highest levels of expression in prespawning animals. These results would implicate the role of POM and POC in some developmental processes but not in the initiation of metamorphosis. The very high levels of POM and POC expression in prespawner animals suggest that the two genes may have important roles at this time in the life cycle of lampreys.

Animals↗
PubMed1998

Isolation and characterization of insulin in Russian sturgeon (Acipenser guldenstaedti).

Insulin was isolated from the pancreas of Chondrostean fish, the Russian sturgeon, Acipenser guldenstaedti, by acid-ethanol extraction followed by ion-exchange and reverse-phase high-performance liquid chromatographies. The amino acid sequence determined by automated Edman degradation is as follows: A-chain (21-amino-acid peptide), H-Gly-Ile-Val-Glu-Gln-Cys-Cys-His-Ser-Pro-Cys-Ser-Leu-Tyr-Asp-Leu-Glu-As n-Tyr-Cys-Asn-OH; and B-chain (31-amino-acid peptide), H-Ala-Ala-Asn-Gln-His-Leu-Cys-Gly-Ser-His-Leu-Val-Glu-Ala-Leu-Tyr-Leu-Va l-Cys-Gly-Glu-Arg-Gly-Phe-Phe-Tyr-Thr-Pro-Asn-Lys-Val-OH. The sturgeon insulin appears to be identical with one of two forms of paddlefish insulin and differs from the other form by a single substitution in the A-chain, Asp15: His15. The amino acid sequence of sturgeon insulin is more similar to the amino acid sequence of mammalian insulins than of other fish insulins. Sturgeon insulin showed parallel but weaker displacement than porcine insulin and pink salmon insulin in their respective radioimmunoassays and was less potent than porcine insulin in displacing radiolabeled porcine insulin bound to partially purified rat liver plasma membranes.

Amino Acid Sequence↗