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Biomedical subjects

C Yanaihara

Publications and source records attributed to C Yanaihara.

At least 37 records · Page 2Linked to original sources
PubMed1990

Ultrastructural identification of human secretin cells by the immunogold technique. Their costorage of chromogranin A and serotonin.

We have localized secretin in a morphologically distinctive endocrine cell scattered in the epithelium covering the villi and uppermost crypts of the human duodenum and jejunum. The human secretin cell was characterized by relatively large (mean diameter 299 nm +/- 69 SD), fairly irregular granules, the majority of which showed homogeneous distribution of secretin and chromogranin A immunolabelling in a structurally homogeneous core. Other granules had a targetoid pattern due to an inner, argyrophobe, secretin-immunoreactive body surrounded by an argyrophil, chromogranin A immunoreactive mantle. These targetoid granules represent a distinctive ultrastructural marker of the secretin cell. Secretin cell granules have been shown to react with chromogranin A antibodies and Grimelius' silver, while lacking chromogranin B immunoreactivity. About 1/3 of secretin cells also showed serotonin immunostaining.

APUD Cells↗
PubMed1990

Content and distribution of vasoactive intestinal polypeptide (VIP) in cavernous tissue of human penis.

Penile erection is controlled by a valvular structure in the helicine artery in humans. The opening and closing of this valve are believed to be regulated by the autonomic nervous system, especially through the release of vasoactive intestinal polypeptide (VIP). We determined the content of VIP in cavernous tissue in 18 impotent patients and in 5 normal controls by radioimmunoassay, and we examined the distribution of VIP-ergic nerve fibers in cavernous tissue by an immunohistochemical method. As a result, it was found that the lower penile VIP content was more frequent among patients with organic impotence than among the controls. Furthermore, VIP-ergic nerve fibers were seen to be diffusely and loosely distributed in a large number of organic impotence patients. These findings suggest that organic impotence in some patients may be due to decreases in the VIP content and in VIP-ergic nerve fibers.

Adolescent↗
PubMed1990

Epidermal growth factor and its receptors in human pancreatic carcinoma.

The role of epidermal growth factor (EGF) in oncogenesis and progression of malignant tumors is a subject of vast interest. In this study, radioimmunoassay and radioreceptor assay of EGF were established. EGF contents in malignant and benign pancreatic tumors, in normal pancreas tissue, and in culture media of a human pancreatic carcinoma cell line were determined. EGF receptor binding studies were performed. It was shown that EGF contents in pancreatic carcinomas were significantly higher than those in normal pancreas or benign pancreatic tumors. EGF was also detected in the culture medium of a pancreatic carcinoma cell line. The binding of 125I-EGF to the pancreatic carcinoma cells was time and temperature dependent, reversible, competitive, and specific. Scatchard analysis showed that the dissociation constant of EGF receptor was 2.1 X 10(-9) M, number of binding sites was 1.3 X 10(5) cell. These results indicate that there is an over-expression of EGF/EGF receptors in pancreatic carcinomas, and that an autocrine regulatory mechanism may exist in the growth-promoting effect of EGF on tumor cells.

Epidermal Growth Factor↗
PubMed1990

Gonadotropin-releasing hormone-associated peptide immunoreactivity in bovine colostrum.

Gonadotropin-releasing hormone(GnRH)-associated peptide (GAP) is a 56-amino acid peptide found on the C-terminal of the GnRH (also called luteinizing hormone-releasing hormone) precursor and is assumed to be co-produced with GnRH. The purpose of this report is to demonstrate the presence of GAP immunoreactivity in bovine colostrum. Radioimmunoassay of acidified methanolic extracts demonstrated a concentration of GAP immunoreactivity of approximately 1.5 +/- 0.1 pmol/g dry skim bovine colostrum. Gel filtration (Sephadex G-10) and high-performance liquid chromatography of extracts containing GAP immunoreactivity showed it to be of low molecular weight and a high hydrophobic character. The presence of GAP immunoreactivity in bovine colostrum suggests that the GnRH precursor is synthesized and processed in mammary tissue itself.

Animals↗
PubMed1989

Immunocytochemical analysis of [Met5]enkephalin-Arg6-Gly7-Leu8 immunoreactive structures in the rat superior cervical ganglion.

Indirect immunofluorescence and immunoelectron microscopy were employed to analyze the enkephalinergic systems in the rat superior cervical ganglion (SCG). These systems were identified using specific antiserum against [Met5]Enkephalin-Arg6-Gly7-Leu8 (ENK-8), a peptide which is derived only from proenkephalin A. Abundant ENK-8 like immunoreactive (ENK-8-LI) neurons and fibers were observed in the SCG, but their distribution patterns were heterogenous; ENK-8-LI neurons were localized preferentially in the caudal two-thirds of the SCG, while immunoreactive fibers were found to be distributed more densely in the rostral one-third than in the remaining part of the SCG. Most of the ENK-8-LI neurons were large and had ultrastructural features resembling those of principal cells, some were identified electron microscopically as small intensely fluorescent (SIF) cells. ENK-8-LI fibers were varicose in appearance and surrounded the perikarya of neurons. Since most of these fibers were not detected after experimental decentralization of the SCG and since ENK-8-LI terminals were seen to contain small lucent vesicles, most of the former were thought to be preganglionic fibers. Immunoreactive fibers mainly formed synaptic contacts with the dendrites of non-immunoreactive principal cells, but a small proportion of ENK-8-LI principal cells also received synaptic input from them. Occasionally, immunoreactive fibers formed synapses with the processes or the soma of both ENK-8-LI and non-immunoreactive SIF cells. On the basis of these findings, we conclude that: (1) preganglionic ENK-8-LI fibers terminate mainly on the principal cells, which are devoid of ENK-8-LI structures; (2) the majority of ENK-8-LI neurons are principal cells, while the remainder are SIF cells; (3) inputs to these cells mainly involve structures lacking ENK-8 immunoreactivity; and (4) there are, however, a small number of ENK-8-LI preganglionic fibers which terminate on ENK-8-LI principal cells and SIF cells.

Animals↗
PubMed1989

Proenkephalin opioid peptide product in the sensory ganglia of the rat: a developmental immunohistochemical study.

The distribution and development of Met-enkephalin-Arg6-Gly7-Leu8 (Enk-8)-containing neurons in the sensory ganglia of the rat were investigated by means of immunocytochemistry using specific antiserum to this octapeptide. Enk-8-like immunoreactivity first appeared in neurons of the trigeminal ganglia of the 18-day embryo, then in the dorsal root ganglia of the 21-day embryo, thus exhibiting a rostrocaudal gradient in terms of appearance and abundance. The number of immunoreactive neurons in these sensory ganglia peaked on the 5th-7th postnatal days, with several small ones observed in each section (1.0-1.4% of total cell number). About 30-40% of these Enk-8-like immunoreactive neurons were also immunoreactive to substance P. Subsequently, Enk-8-like immunoreactivity in the sensory ganglia was decreased and was rarely detected in adult animals. However, colchicine treatment revealed the presence of several Enk-8-containing neurons per section prepared from mature rat. All these neurons were small (12.5-25 microns; mean +/- S.E.M., 19.86 +/- 3.26 microns). Some of these were also immunoreactive to substance P. These results strongly suggest that the preproenkephalin A system exists in subpopulations of both developing and matured sensory cells in the rat. Functional significance of this is discussed.

Aging↗
PubMed1989

Effects of growth hormone releasing factor on pancreatic secretion in vivo and in vitro.

Growth hormone releasing factor (GRF), a 44-residue peptide originally isolated from human pancreatic tumors, shows structural similarities to the members of the secretin-vasoactive intestinal peptide (VIP) peptides. This study was designed to determine the effects of human GRF (hGRF-(1-44] on pancreatic secretion in vivo in conscious dogs and in vitro in dispersed rat pancreatic acini. GRF given i.v. in graded doses in dogs caused a small but significant stimulation of pancreatic HCO3- and protein outputs and potentiated secretin- and cholecystokinin (CCK)-induced pancreatic HCO3- but not protein secretion. When given together with somatostatin, GRF failed to reverse the inhibitory action of this peptide on HCO3- and protein responses to secretin plus CCK in dogs. Studies in vitro dispersed rat pancreatic acini showed that GRF added to the incubation medium of these acini caused an increase in basal amylase release and shifted to the left the amylase dose-response curve to caerulein and urecholine but failed to affect the amylase response to VIP. This study indicates that GRF in vivo stimulates basal and augments secretin- or CCK-induced pancreatic HCO3- secretion and that this is probably due to direct stimulatory action of the peptide on pancreatic secretory cells.

Amylases↗
PubMed1989

IGF-II-like immunoreactivity in human tissues, neuroendocrine tumors, and PC12 cells.

We looked for cells that reacted with monoclonal antibodies against rat insulin-like growth factor II (IGF-II). We found them in human fetal kidneys in the 14th week of gestation and in adult adrenal medullas but not in human liver, pancreas, pituitary gland, or thymus. Every pheochromocytoma in a group of 20 had IGF-II-like immunoreactive cells, as did three out of four ganglioneuroblastomas (one of which was heterotransplantable in athymic nude mice) and one carotid body tumor. Using the electron microscope we localized the immunoreactivity in pheochromocytoma cells to their neurosecretory granules of the non-catecholamine type. We failed to find any IGF-II-reactive cells among the pancreatic islet cell tumors, neuroblastomas, medullary carcinomas of the thyroid, retinoblastomas, and Wilms' tumor we studied. One line of human neuroblastoma cells did show some immunoreactivity after treatment with dbcAMP. Additionally, the rat pheochromocytoma cell line PC12 and its subline PC12h occasionally produced a few immunostained cells. These results strongly indicate that human IGF-II is primarily produced in paraganglionic tissues and tumors.

Adrenal Gland Neoplasms↗
PubMed1989

Change in solubility of insulin in therapeutic mixtures of insulin preparations: HPLC analysis.

We systematically and quantitatively observed the changes in solubility when short- and intermediate-acting insulin preparations were mixed together, using high-performance liquid chromatography (HPLC) and centrifugation. We tested 30 combinations of 16 kinds of commercial insulin preparations, including six short-acting and eight intermediate-acting preparations. The soluble insulin component in the short-acting preparations examined was in all cases insolubilized to various extents after mixing. Particularly remarkable was the complete precipitation of the insulin from Actrapid Human when it was mixed with Monotard Human (1:1). This sort of drastic change in insulin solubility after mixture was reflected in the changes in blood glucose level after the subcutaneous injection of the mixture to rabbits. The information provided by pharmaceutical companies on absorption kinetics and action profiles of short-acting insulin preparations may no longer be valid when mixtures with longer-acting preparations are used.

Animals↗
PubMed1989

Demonstration of two distinct insulin-binding components in solubilized human placental membranes by radioimmunoassay using synthetic peptide and anti-synthetic peptide antibody.

A peptide corresponding to the 957-980 sequence of human placental insulin receptor precursor (HIRP) was synthesized and antisera were produced against the synthetic peptide. Anti-synthetic HIRP(957-980) serum HIR-27 was proved to cross-react with HIRP-related proteins in solubilized human placental membranes. A radioimmunoassay developed with the antiserum and synthetic peptide HIRP(957-980) enabled us to separate, in combination with gel filtration, two insulin-binding components in solubilized human placental membranes which conceivably correspond to the alpha 2 beta 2 and alpha beta structures of the placental insulin receptor. The two components were shown to be distinct in insulin-binding behavior depending on conditions of pH and ionic strength in the binding assay.

Antibodies↗
PubMed1989

Comparison of CCK-8 receptors in the pancreas and brain of rats using CCK-8 analogues.

The characteristics of cholecystokinin (CCK) receptors in rat pancreatic acini and in various regions of the brain were examined using synthetic CCK-8 or CCK-7 analogues. 3H-propionylated CCK-8 [( 3H]CCK-8) was used as a ligand. 1) The pancreatic CCK receptor had a single high affinity binding component with a dissociation constant, Kd, of 0.76 nM and a maximum number of specific binding sites, Bmax, of 271.91 fmol/mg protein. On the other hand, the CCK receptor in the cerebral cortex had a Kd of 1.66 nM and a Bmax of 30.15 fmol/mg protein. 2) The order of the potencies of CCK-7 and CCK-8 analogues with a substitution at position 3 or 4 to displace [3H]CCK-8 specific binding to the pancreatic acini was as follows: CCK-8 greater than CCK-7 = SucCCK-7 greater than Suc[Sar3]CCK-7 greater than Suc[D-Trp3]CCK-7 greater than Suc[D-Ala3]CCK-7 greater than [D-Trp4]CCK-8 = [D-Ala4] CCK-8. This order of potencies of CCK analogues was greatly different from that in the cerebral cortex. 3) The carboxy-terminal tetra-peptide (CCK-4) and penta-peptide (CCK-5) had very weak potencies in displacing [3H]CCK-8 binding in the pancreatic acini, which were 20 to 30-fold less than their potencies in the cerebral cortex. These results suggest that the recognition sites for CCK analogues in the pancreatic and brain CCK receptors are different.

Animals↗
PubMed1989

Establishment of the specific radioimmunoassay for serum thymic factor (STF).

Serum thymic factor is a humoral factor involved in the differentiation of T cells. In the present study, a radioimmunoassay system for STF was established using a specific antiserum and an iodinated synthetic STF as a tracer. Serum levels of STF-like immunoreactivities were around 30 pg/ml in human, but in contrast to previous reports serum STF levels did not show age-dependent decreases. STF-like immunoreactivities of the thymic gland were lower than those of the liver and kidney in rats. The livers of human and pig contained high STF-like immunoreactivities. The rat thymic gland extract showed three peaks of STF-like immunoreactivity by gel filtration of Sephadex G-25 which corresponded to the eluted position of authentic STF, a larger molecular size, and a smaller molecular size of STF, respectively, while the rat liver extract showed two peaks corresponding to the void volume fraction and to the position of authentic STF, respectively. When this void volume fraction was digested by trypsin, three peaks which corresponded to authentic STF, a larger molecular size, and a smaller molecular size of STF were observed. Present studies suggest that serum thymic factor is produced as a larger STF molecule in the liver and kidney.

Adult↗
PubMed1989

Recent advances in brain-gut hormones.

Although recent advances in gene technology have made it possible to produce peptides and proteins by the recombinant technique, chemical synthesis either by the solution or by the solid-phase technique is still only a method of choice for the syntheses of a brain-gut hormone and its superagonist and/or antagonist. In addition, synthetic replicates of brain-gut hormones, their analogus and fragments or their precursor-related peptides are important haptenic immunogens to produce region-specific antisera to the respective peptides. In the present study, antisera against proglucagon and pro-LH-RH related peptides were proved to be useful not only for identifying hormone-producing cells, but also for demonstrating the post-translational biosynthetic processing in the cells. For galanin, a novel brain-gut hormone, have structural similarity in its C-terminal region to tachykinins, a monoclonal antibody against synthetic porcine galanin (1-15) was prepared for immunohistochemical study. This monoclonal antibody was found to recognize specifically galanin-producing cells and not to cross-react with any of tachykinins examined. These observations indicate that monoclonal antibodies are highly useful for identifying cells possessing a brain-gut hormone containing structures common to those of different known peptides.

Animals↗
PubMed1989

Presence of epidermal growth factor in human tears.

Epidermal growth factor (EGF) is a polypeptide that stimulates the growth of various tissues, including the cornea. The presence of EGF in tears from normal volunteers and in aqueous humor from cataract patients was investigated via human EGF (hEGF)-specific radioimmunoassay. Immunoreactive hEGF was found to be present at similar concentrations in both reflex (ranging from 0.7 to 8.1 ng/ml) and non-reflex tears (ranging from 1.9 to 9.7 ng/ml), but was undetectable in aqueous humor. Immunoreactive EGF in human tears was indistinguishable immunologically, biologically and biochemically from urine EGF and standard hEGF.

Adult↗
PubMed1988

Co-localization of substance P and Met-enkephalin-Arg6-Gly7-Leu8 in the intraspinal neurons of the rat, with special reference to the neurons in the substantia gelatinosa.

A double-labeling immunofluorescence technique was employed to investigate the co-localization of the functionally antagonistic neuropeptides, substance P and enkephalins, within intraspinal neurons of the rat. Anti-Met-enkephalin-Arg6-Gly7-Leu8 (Enk-8) antiserum was used as a marker of the preproenkephalin A neuron system. The observations were focused on the lumbar spinal cord. Co-localization was most prominent within neurons in the substantia gelatinosa, in which more than 95% of substance P-like immunoreactivity neurons showed Enk-8-like immunoreactivity. These double-labeled cells corresponded to 45% of Enk-8-like immunoreactive neurons in the same area. This suggests that SP/Enk-8 interaction occurs at the axon terminals of the substantia gelatinosa neurons. In deeper layers of the dorsal horn (laminae III, IV), only 14% and 6% of SP-like immunoreactive and Enk-8-like immunoreactive neurons were double labeled, respectively. Co-localization was also observed in neurons located in the laminae I, V, VII and X, suggesting concomitant involvement of these peptides in a variety of spinal cord functions.

Animals↗
PubMed1988

Is helodermin produced by medullary thyroid carcinoma cells and normal C-cells? Immunocytochemical evidence.

Helodermin is a VIP/secretin-like 35-amino acid peptide originally isolated from the venom of the lizard Gila monster. Recently, helodermin-immunoreactive material was demonstrated in mammalian salivary glands, brain and gut. In the present study 8 human medullary thyroid carcinomas as well as 4 normal thyroid glands were examined immunocytochemically for the presence of helodermin using an antiserum raised against helodermin-(5-35) that does not cross-react with VIP or secretin. Cells displaying helodermin-like immunoreactivity were found in all tumours examined except one. On the whole the helodermin-immunoreactive cells had the same distribution as those storing calcitonin, suggesting coexistence of the two peptides in most of the tumour cells. Also normal human C-cells displayed helodermin immunoreactivity. The results suggest that a peptide chemically related to helodermin is a constituent of human medullary thyroid carcinoma cells as well as of normal C-cells.

Fluorescent Antibody Technique↗
PubMed1988

Cross-reaction of two different somatostatin antisera with calcitonin gene-related peptide.

Two different anti-somatostatin antisera, R-101 and OAL-273, cross-react with rat calcitonin gene-related peptide (1-37) (CGRP). CGRP amounts, in excess of 6.25 x 10(-9) M, cross-react with R-101 in the somatostatin radioimmunoassay. CGRP amounts, in excess of 1.6 x 10(-9) M, cross-react with OAL-273. Both CGRP displacement curves are parallel to that of synthetic somatostatin (1-14). Comparison of ID50's shows that the cross-reactivity of CGRP with R-101 and OAL-273 are 0.02 and 0.1% of somatostatin, respectively.

Amino Acid Sequence↗