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Biomedical subjects

H Matsuo

Publications and source records attributed to H Matsuo.

At least 19 recordsLinked to original sources
PubMed1992

Isolation and identification of C-type natriuretic peptide in human monocytic cell line, THP-1.

In a survey for unknown bioactive peptides in mammalian cell lines, we isolated peptides exhibiting a strong relaxant effect on chick rectum from a phorbol ester-supplemented culture medium of the human monocytic cell line, THP-1. The peptide was deduced to be a C-terminal 29-residue peptide derived from a human C-type natriuretic peptide (CNP) precursor. CNP mRNA was also detected in the THP-1 cells, and expression of CNP gene and CNP concentration in the culture medium was found to be highly augmented by the stimulation of phorbol ester. Production of CNP in THP-1 cells suggests that CNP also functions as a local regulator in the blood cell-vascular system, although CNP has previously been recognized as a neuropeptide functioning in the central nervous system.

Amino Acid Sequence↗
PubMed1992

Stable expression of natriuretic peptide receptors: effects of HS-142-1, a non-peptide ANP antagonist.

We established clonal cell lines stably expressing each of two subtypes of membrane bound guanylate cyclases (GC-A and GC-B), which are known as natriuretic peptide receptors. Using these cell lines, we showed that GC-A is an ANP/BNP receptor, whereas GC-B is a specific receptor for CNP. Effects of HS-142-1, a novel non-peptide ANP antagonist, on GC-A and GC-B were examined by using these cells. In cells expressing either GC-A or GC-B, HS-142-1 inhibited cGMP production elicited by ANP or CNP with IC50 values of 1.8 micrograms/ml and 1.5 micrograms/ml, respectively, and also competitively blocked specific binding of the natriuretic peptides with IC50 values of 2.2 micrograms/ml and 3.3 micrograms/ml, respectively. These results indicate that HS-142-1 is a potent antagonist of CNP as well as ANP. We also showed that CNP suppressed the growth of cells expressing GC-B by 22% and that HS-142-1 blocked the antiproliferative action of CNP.

Animals↗
PubMed1992

Cloning and characterization of an androgen-induced growth factor essential for the androgen-dependent growth of mouse mammary carcinoma cells.

An androgen-dependent mouse mammary carcinoma cell line (SC-3) requires androgen for growth stimulation. We have shown previously that androgen acts on SC-3 cells to induce secretion of a fibroblast growth factor (FGF)-like growth factor, which in turn stimulates growth of the cells in an autocrine manner. In this study, the androgen-induced growth factor (AIGF) was purified from a conditioned medium of SC-3 cells stimulated with testosterone. cDNA cloning of AIGF by use of its partial amino acid sequence data revealed that AIGF is a distinctive FGF-like growth factor. An AIGF cDNA (pSC17) encodes a 215-amino acid protein with a putative signal peptide, which shares 30-40% homology with known members of the FGF family. The AIGF mRNA was markedly induced by 10 nM testosterone in Northern blot analysis. Expression of AIGF cDNA in mammalian cells clearly showed remarkable stimulatory effects of AIGF on growth of SC-3 cells in the absence of androgen. Thus, it is clear that the androgen-induced growth of SC-3 cells is mediated in an autocrine manner by AIGF, which is secreted by the tumor cells themselves in response to hormonal stimuli.

Amino Acid Sequence↗
PubMed1992

Organ distribution and characterization of porcine peptides (VIP, CGRP and PHI) that increase cAMP in rat platelets.

Using an assay for rat platelet cAMP, we investigated the organ distribution of peptides that increase cAMP in rat platelets in porcine tissues. Marked activity was observed in the duodenum, pancreas and brain. By analysis with reverse phase high performance liquid chromatography (HPLC), three major peaks of activity were observed in porcine tissues. The first peak was vasoactive intestinal polypeptide (VIP), and the second peak was calcitonin gene-related peptide (CGRP). The third peak of activity was isolated from porcine duodenum. By analysis with a gas phase sequencer and with an amino acid analyzer, this peptide was identified as peptide histidine isoleucine (PHI). In a glucagon-secretin family of neuropeptides, pituitary adenylate cyclase activating polypeptide (PACAP) significantly increased platelet cAMP levels in a dose-dependent manner; however, glucagon did not. These results suggest that not only VIP and CGRP but also PHI and PACAP act upon platelets, as well as vascular tissues.

Amino Acid Sequence↗
PubMed1992

Establishment of hypersensitive radioimmunoassay for islet amyloid polypeptide using antiserum specific for its N-terminal region.

Using a synthetic N-terminal hexadecapeptide of islet amyloid polypeptide (IAPP), we prepared an antiserum specific for IAPP[1-16] and established an extremely sensitive radioimmunoassay (RIA) for the peptide with a minimum detection level of 0.26 fmol/tube. Since the N-terminal sequence of IAPP is 100% conserved in many mammalian species, the RIA is widely applicable in quantifying their IAPP. Analyses of pancreatic extracts of human and hamster using reverse-phase high performance liquid chromatography coupled with the RIA revealed that almost all pancreatic IAPP consisted of IAPP[1-37]. On the other hand, rat and mouse pancreata contained substantial amounts of IAPP[1-16] and IAPP[1-17] in addition to IAPP[1-37] as a major molecular form. In human plasma, IAPP[1-37] is the major molecular form secreted into the circulation in response to glucose administration. The RIA established in this study is promising in elucidating the physiological functions and the pathophysiological significance of IAPP in diabetes mellitus.

Adult↗
PubMed1992

Identification of a novel transthyretin variant (Val30----Leu) associated with familial amyloidotic polyneuropathy.

A novel variant transthyretin which contains a leucine-for-valine substitution at position 30 was isolated and identified in the serum of a patient with familial amyloidotic polyneuropathy (FAP). The amino acid substitution was proven to result from a guanine-to-cytosine change at the first base of codon 30 located in exon 2 in the mutated transthyretin gene by restriction fragment length analysis on the amplified transthyretin gene using Cfr13 I. The study indicates that the point mutation of the transthyretin gene is a cause of the disorder.

Amino Acid Sequence↗
PubMed1992

Concentrations and molecular forms of human brain natriuretic peptide in plasma.

Using a highly sensitive radioimmunoassay (RIA) system for human brain natriuretic peptide (BNP), immunoreactive (ir-) human BNP was found to be present in plasma, in addition to heart and brain tissue. Plasma concentrations of ir-BNP were 0.17-0.74 fmol/ml (mean: 0.35 fmol/ml) in normal young men, being about 1/17 of the plasma concentration of human atrial natriuretic peptide (ANP). In patients with heart disease, plasma concentration of ir-BNP increased about 100-fold (5.00-177.37 fmol/ml), being nearly comparable to that of ir-ANP, even though ANP concentration also increased about 7-fold. Two molecular forms of ir-BNP in plasma were identified as BNP-32 and gamma-BNP (pro-BNP), which are also found in cardiac atrium. In normal human plasma, gamma-BNP is the predominant molecular form, while the main form in cardiac atrium is BNP-32. These results suggest that biosynthesis and secretion of BNP are augmented in heart disease and that human BNP has a unique processing and metabolic system distinct from that of ANP.

Chromatography, Affinity↗
PubMed1992

Isolation and characterization of peptides which act on rat platelets, from a pheochromocytoma.

An increase in the cellular concentration of cAMP leads to the inhibition of platelet aggregation. We have been investigating endogenous peptides which inhibit platelet function, using an assay which detects increase in platelet cAMP. Compared with the human adrenal medulla, a pheochromocytoma (PC) contained abundant peptides that elevate platelet cAMP. About 90% of the activity was found in the SP-III fraction which contained strongly basic peptides. From the SP-III fraction, peptides P-1, P-2 and P-3 were purified to homogeneity as endogenous peptides which elevated platelet cAMP. A gas phase sequencer was used to identify these peptides as follows: P-1 = vasoactive intestinal peptide (VIP); P-2 = calcitonin gene related peptide-I (CGRP-I); P-3 = CGRP-II. It is well known these peptides are potent vasorelaxants. VIP and CGRP-I significantly increased platelet cAMP levels 15- and 6-fold, respectively. These results suggest that VIP and CGRP-I and -II act upon platelets as well as upon vascular tissue.

Adrenal Gland Neoplasms↗
PubMed1992

Expression of thymosin beta 4 gene during Xenopus laevis embryogenesis.

In order to investigate the molecular events which take place during gastrulation, extracts from developing Xenopus embryos were analyzed for temporal peptide distribution by high performance liquid chromatography. One peptide peak which became increasingly dominant after gastrulation was purified and partially characterized. The amino acid sequence of enzymic digests showed the peptide is extremely similar to mammalian thymosin beta 4. The peptide was capable of binding actin monomers like mammalian counterparts. Cloning of the Xenopus thymosin beta 4 cDNA showed that only three amino acid substitutions occurred between amphibian and bovine. Northern blot analysis revealed the mRNA is maternally present at a low level and the transcript becomes abundant after gastrulation, supporting the distribution of the peptide.

Amino Acid Sequence↗
PubMed1992

Structural requirements of C-type natriuretic peptide for elevation of cyclic GMP in cultured vascular smooth muscle cells.

C-type natriuretic peptide (CNP), which was recently found to be a selective ligand for one of the two known natriuretic peptide receptor guanylyl cyclases (NPR-B), potently stimulates cGMP production in cultured rat vascular smooth muscle cells (VSMC) and exerts potent antiproliferative effects on the cells. To investigate the structural requirements of CNP for stimulation of cGMP accumulation via NPR-B, we prepared CNP analogs and tested them on cultured rat VSMC. Our results indicate that only the ring portion of CNP with a disulfide bond (CNP(6-22)) participates in stimulation of cGMP accumulation, especially the sequence Leu9-Lys10-Leu11 in the ring portion executes essential roles for both elevation of cGMP and selectivity of the ligand for NPR-B. We also found a good correlation between the activities of the CNP analogs for stimulation of cGMP accumulation and inhibition of DNA synthesis.

Amino Acid Sequence↗
PubMed1992

Cloning and characterization of two forms of C-type natriuretic peptide receptor in rat brain.

Two similar membrane bound guanylate cyclases (GC-A and GC-B) are known as natriuretic peptide receptors, but have not been well characterized yet. In this study, we have isolated two forms of GC-B cDNA clones along with GC-A cDNA clones from rat brain. The two forms of rat GC-B differ from each other only by 75bp deletion at 3'-flanking region of the putative transmembrane domain, the shorter form lacking the nucleotide binding site by the deletion. Expression of these cDNAs on mammalian cells revealed that (1) GC-B is a specific receptor for CNP whereas GC-A is stimulated effectively both by ANP and BNP, and (2) the two forms of GC-B possess practically the same high binding affinity for CNP while the shorter form could not induce cGMP production by the binding of CNP. These data indicate that in rat brain is present the non-functional receptor for CNP caused by the short deletion.

Amino Acid Sequence↗
PubMed1992

Characterization of atrial natriuretic peptide in urine from rats treated with a neutral endopeptidase inhibitor.

To explore the mechanisms for the natriuretic effects of a neutral endopeptidase inhibitor, candoxatril, the concentration of atrial natriuretic peptide (ANP) and its molecular forms in the urine of Dahl salt-sensitive (S) rats were examined. Candoxatril-induced natriuresis (+120%, p less than 0.05) was associated with a marked increase in the urinary ANP excretion (+1200%, p less than 0.05). Analysis by Sephadex G-50 gel filtration revealed that molecular weight of the major fraction of immunoreactive (ir-) ANP in the plasma of candoxatril-treated Dahl S rats was 3K, whereas that in the urine was 2.5 K. Further analysis by reverse phase high performance liquid chromatography showed that ir-ANP in the plasma of Dahl S rats was alpha-rANP (1-28), while that in the urine from rats treated with candoxatril was alpha-rANP (1-25). These results indicate that candoxatril inhibits the complete degradation of ANP in the kidney, thereby increasing the amount of biologically active ANP reaching the distal nephron and contributing to natriuresis.

Analysis of Variance↗
PubMed1992

Myasthenogenicity of a human acetylcholine receptor alpha-subunit peptide: morphology and immunology.

Each of 10 rats inoculated with a synthetic peptide comprising residues 125-147 (without a disulfide bond) of human acetylcholine receptor (AChR) alpha-subunit (H alpha) had deposits of IgG and C3 (immune complexes) and showed morphological changes in the fine structure at the motor end-plates 5 weeks after a single immunization. Antibody to the H alpha peptides was elevated 1 week after immunization, but, antibody levels to solubilized human or rat AChR were very low in 8 of the 10 rats. These results suggest that the immune response to peptide H alpha is the myasthenogenic site, which induces morphological change at the end-plates.

Animals↗
PubMed1992

Effects of aging on plasma islet amyloid polypeptide basal level and response to oral glucose load.

To delineate the effects of aging on basal and glucose-stimulated secretion of islet amyloid polypeptide (IAPP), we compared the basal level of plasma IAPP and its response to an oral glucose load in elderly subjects with those of young subjects. Plasma IAPP level was determined by radioimmunoassay. Basal level of plasma IAPP in 20 elderly subjects (mean age 63 yr) was 5.3 +/- 0.4 pmol/l, which was not significantly different from 5.0 +/- 0.3 pmol/l in 22 young subjects (mean age 26 yr). Plasma glucose levels after an oral glucose load in elderly subjects (n = 8, mean age 67 yr) and young subjects (n = 8, mean age 29 yr) were within normal limits. However, the plasma glucose response in the aged group was significantly higher than that in the young group. The plasma insulin response to a glucose load in elderly subjects was not different from that in young subjects. The plasma IAPP level in the aged group significantly increased from 5.3 +/- 0.5 to 16.4 +/- 2.3 pmol/l 120 min after the oral glucose load. This result was quite similar to that in the young group whose plasma IAPP level increased from 4.9 +/- 0.5 to 14.1 +/- 1.5 pmol/l 120 min after the glucose load. We concluded that the basal level of plasma IAPP and its response to glucose were not affected by aging.

Adult↗
PubMed1992

Molecular forms of islet amyloid polypeptide (IAPP/amylin) in four mammals.

Using reverse-phase high performance liquid chromatography combined with radioimmunoassays for human and rat/mouse islet amyloid polypeptide (IAPP), we identified molecular forms of IAPPs in pancreata of four mammals including species in which islet amyloid deposition occurs (human and cat) and those in which amyloid deposition does not occur (rat and mouse). In human pancreas, IAPP (1-37) was the major molecular form, and IAPP (17-37), IAPP (24-37) and four IAPP-immunoreactive peptides were detected as minor components. In rat, mouse and cat pancreata, IAPP (1-37) and IAPP (19-37) were identified with the latter being the major molecular form. Major processing takes place at a single arginine residue at position 18 of rat/mouse and cat IAPPs, but not at the histidine at position 18 of human IAPP, indicating that arginine could yield different processing of IAPP between the 3 species and human. Different processing of IAPP by species suggests that processing of IAPP in pancreas is not responsible for islet amyloid formation. Identification of molecular forms of IAPP is helpful in elucidating the physiological function of the IAPP molecule and in determining the type of system regulating biosynthesis and catabolism of the peptide.

Amino Acid Sequence↗
PubMed1992

A novel change in cytologic localization of human chorionic gonadotropin and human placental lactogen in first-trimester placenta in the course of gestation.

Cytologic localization of human chorionic gonadotropin and human placental lactogen in developing human early placenta was analyzed by avidin-biotin immunoperoxidase techniques with an affinity-purified polyclonal antibody to beta-human chorionic gonadotropin carboxyl terminal peptide and a polyclonal antibody to human placental lactogen. In 4- to 5-week placentas human chorionic gonadotropin and human placental lactogen were found to be primarily localized to cytotrophoblasts, whereas in 6- to 12-week placentas these substances were exclusively localized to syncytiotrophoblast. We previously reported that a similar change in cytologic localization of epidermal growth factor and its receptor from cytotrophoblasts to syncytiotrophoblast in first-trimester placenta appeared between 5 and 6 weeks of gestation. Because epidermal growth factor was demonstrated to stimulate human chorionic gonadotropin and human placental lactogen production by early placental tissues, their simultaneous expression, as well as epidermal growth factor and its receptor in the cytotrophoblast of 4- to 5-week placenta and in the syncytiotrophoblast of 6- to 12-week placenta, implies that human chorionic gonadotropin and human placental lactogen production by first-trimester placenta may be regulated in an autocrine manner, wherein epidermal growth factor may serve as the signal. These findings suggest that in very early placenta, before 6 weeks of gestation, no sequential expression of human chorionic gonadotropin and human placental lactogen closely linked to syncytia formation may exist and that both can be expressed in the cytotrophoblast or undifferentiated stem cell of villous trophoblast in very early placenta.

Chorionic Gonadotropin↗
PubMed1992

In vivo and in vitro effects of atrial natriuretic peptide on renin release.

1. This study investigated the effect of atrial natriuretic peptide on renin release from the kidney. The in vitro direct effect was examined in the animal experiment using renal cortical slices of rat, and the in vivo effect was observed in the human infusion study. 2. In the in vitro experiments, alpha-human atrial natriuretic peptide (alpha-hANP) ranging 10(-9) to 10(-6) mol/L did not change the basal renin release rate from the renal cortical slices (-9% at 10(-6) mol/L, NS). Isoproterenol (10(-6) mol/L) increased renin release by 40% (P < 0.001), whereas angiotensin II (10(-6) mol/L) suppressed it by 48% (P < 0.001). However, alpha-hANP did not affect the stimulative effect of isoproterenol or the inhibitory effect of angiotensin II. 3. Also in the human study, infusion of 25 ng/kg per min alpha-hANP failed to change the plasma renin activity in normotensive subjects (-4%) or patients with essential hypertension (+5%), or even in patients with raised renin levels such as renovascular hypertension (+10%) or congestive heart failure (-13%). 4. These results put forth negative views on the direct involvement of atrial natriuretic peptide in renin release from the juxtaglomerular apparatus.

Adult↗