Biomedical subjects

K Totsune

Publications and source records attributed to K Totsune.

At least 37 records · Page 2Linked to original sources

PubMed2000

Secretion of endothelin-1 and adrenomedullin by SW-13 human adrenocortical carcinoma cells.

The adrenal medulla and pheochromocytomas are known to secrete various neuropeptides and vasoactive peptides. On the other hand, the production and secretion of peptides by adrenocortical tumors have not been studied in detail. The study reported here therefore set out to examine these two functions for two vasoactive peptides, endothelin-1 (ET-1) and adrenomedullin (ADM) in SW-13 human adrenocortical carcinoma cells by radioimmunoassay and Northern blot analysis. Both immunoreactive ET (irET) and irADM were detected in the culture medium of SW-13 cells. Northern blot analysis showed the expression of ET-1 and ADM mRNAs in SW-13 cells. On the other hand, no significant amounts of calcironin-gene-related peptide, corricotropin-releasing-hormone, neuropeptide Y or urocorlin were secreted by SW-13 cells. This study has shown that ET-1 and ADM are the two unique vasoactive peptides that are produced and secreted by adrenocortical carcinoma cells.

Adrenal Cortex Neoplasms↗

PubMed2000

Increased gene expression of adrenomedullin and adrenomedullin-receptor complexes, receptor-activity modifying protein (RAMP)2 and calcitonin-receptor-like receptor (CRLR) in the hearts of rats with congestive heart failure.

Adrenomedullin is a vasodilator peptide produced in various organs, including heart and kidney. A novel adrenomedullin receptor complex has recently been identified, namely the calcitonin receptor-like receptor (CRLR) and receptor-activity modifying protein (RAMP) 2. In the present study, we have examined gene expression of RAMP2, CRLR and adrenomedullin in hearts and kidneys of rats with congestive heart failure caused by coronary artery ligation. Partial cloning was performed to determine the rat RAMP2 nucleotide sequence. Messenger RNA levels were then determined using competitive, quantitative reverse transcription-PCR techniques. Significantly increased expression levels (means+/-S.E.) of RAMP2, CRLR and adrenomedullin mRNA were found in the atrium (1.8+/-0.2-fold, 1. 8+/-0.2-fold and 2.1+/-0.1-fold, respectively, compared with sham operated rats) and in the ventricle (1.4+/-0.1-fold, 1.3+/-0.03-fold and 3.0+/-0.5-fold respectively). On the other hand, expression levels of RAMP2, CRLR and adrenomedullin mRNAs were not significantly changed in the kidney. These findings suggest potential roles of locally-produced and locally-acting adrenomedullin in the failing heart.

Adrenal Medulla↗

PubMed1999

Elevated plasma immunoreactive neuropeptide Y concentrations and its increased urinary excretion in patients with advanced diabetic nephropathy.

Neuropeptide Y (NPY) is a potent vasoconstrictor peptide that is abundant in the brain and the peripheral sympathetic nervous system. In the present study we investigated possible changes in plasma immunoreactive (IR)-NPY concentrations and urinary IR-NPY excretion in patients with non-insulin dependent diabetes mellitus (NIDDM) and the relationship to diabetic complications, such as nephropathy and neuropathy. IR-NPY in plasma and urine was measured by radioimmunoassay in 69 patients with NIDDM. Plasma IR-NPY concentrations in patients with advanced nephropathy (creatinine clearance <30 ml/min) (100.5 +/- 10.3 pmol/l, n=9, mean +/- SEM) were higher than in the control subjects (55.0 +/- 6.8 pmol/l, n=15) (P<0.02). Urinary excretion of IR-NPY and fractional excretion of NPY were also increased in the patients with advanced nephropathy. Sephadex G-50 column chromatography of the urine extracts obtained from healthy subjects, diabetic patients with renal failure and non-diabetic patients with renal failure showed an immunoreactive peak eluting in the NPY position. On the other hand, neither plasma nor urinary IR-NPY was high in patients with retinopathy, or in patients with peripheral neuropathy. The present study has, for the first time, shown high plasma IR-NPY concentrations and urinary IR-NPY excretion in NIDDM patients with advanced nephropathy.

Adolescent↗

PubMed1998

Regional distribution of urocortin-like immunoreactivity and expression of urocortin mRNA in the human brain.

Regional distribution of urocortin-like immunoreactivity (UCN-LI) in the human brain was studied by radioimmunoassay and was compared with that of corticotropin-releasing hormone (CRH). In addition, the expression of UCN mRNA was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) method. UCN-LI was detected in every region of brain examined, including hypothalamus, pons, cerebral cortex, and cerebellum. The concentrations of UCN-LI in the human brain were approximately 3 pmol/g wet weight in any brain region, and no marked regional difference was noted. On the other hand, the highest concentrations of CRH-LI were found in the frontal cortex, temporal cortex, and hypothalamus and the lowest in the pons. Reverse phase high-performance liquid chromatography of the UCN-LI in the human brain extract showed two immunoreactive peaks; one peak eluting earlier and one in the position of synthetic human UCN. RT-PCR showed that UCN mRNA was expressed in every region of brain examined. These findings indicated that UCN and UCN mRNA were widely expressed in the human brain.

Adult↗

PubMed1998

Expression of adrenomedullin mRNA in adrenocortical tumors and secretion of adrenomedullin by cultured adrenocortical carcinoma cells.

Immunoreactive-adrenomedullin concentrations and the expression of adrenomedullin mRNA were studied in the tumor tissues of adrenocortical tumors. Northern blot analysis showed the expression of adrenomedullin mRNA in tumor tissues of adrenocortical tumors, including aldosterone-producing adenomas, cortisol-producing adenomas, a non-functioning adenoma and adrenocortical carcinomas, as well as normal parts of adrenal glands and pheochromocytomas. On the other hand, immunoreactive-adrenomedullin was not detected in about 90% cases of adrenocortical tumors (<0.12 pmol/g wet weight (ww)). Immunoreactive-adrenomedullin concentrations ranged from 0.44 to 198.2 pmol/g ww in tumor tissues of pheochromocytomas and were 9.2 +/- 1.2 pmol/g ww (mean +/- SD, n = 4) in normal parts of adrenal glands. Adrenomedullin mRNA was expressed in an adrenocortical adenocarcinoma cell line, SW-13 and immunoreactive-adrenomedullin was detected in the culture medium of SW-13 (48.9 +/- 1.8 fmol/10(5) cells/24h, mean +/- SEM, n = 4). On the other hand, immunoreactive-adrenomedullin was not detectable in the extract of SW-13 cells (<0.09 fmol/10(5) cells), suggesting that adrenomedullin was actively secreted from SW-13 cells without long-term storage. These findings indicate that adrenomedullin is produced and secreted, not only by pheochromocytomas, but also by adrenocortical tumors. Undetectable or low levels of immunoreactive-adrenomedullin in the tumor tissues of adrenocortical tumors may be due to very rapid secretion of this peptide soon after the translation from these tumors.

Adrenal Cortex Neoplasms↗

PubMed1998

Production and secretion of endothelin-1 by cultured choroid plexus carcinoma cells.

Choroid plexus carcinoma is a rare neoplasm derived from the epithelium of the choroid plexus. The production and secretion of endothelin-1 (ET-1) by cultured human choroid plexus carcinoma cells were studied by radioimmunoassay and Northern blot analysis. Immunoreactive (IR)-ET was detected in the culture medium (2.78 +/- 0.12 fmol/10(5) cells/24 h; n = 5; mean +/- SEM) but not in the unconditioned medium. Reverse-phase high-performance liquid chromatography of the extract of the culture medium showed a single peak eluting in the position of ET-1. Treatment with tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) or a combination of interferon-gamma (IFN-gamma), TNF-alpha, and IL-1 beta caused significant increases in the IR-ET levels in the culture medium. Northern blot analysis of total RNA showed the expression of ET-1 mRNA in choroid plexus carcinoma cells. The expression levels of ET-1 mRNA were increased by treatment with a combination of IFN-gamma, TNF-alpha, and IL-1 beta. The present study has shown the production and secretion of ET-1 by cultured human choroid plexus carcinoma cells and suggests the possibility that ET-1 formation is related to the pathophysiology of this tumor.

Blotting, Northern↗

PubMed1998

Production and secretion of two vasoactive peptides, endothelin-1 and adrenomedullin, by a colorectal adenocarcinoma cell line, DLD-1.

Production and secretion of endothelin-1 (ET-1) and adrenomedullin (ADM) by a cultured human colorectal adenocarcinoma cell line, DLD-1, were studied by radioimmunoassay and Northern blot analysis. Both immunoreactive (IR)-ET and IR-ADM were detected by radioimmunoassay in the culture medium of DLD-1 (IR-ET 0.86 +/- 0.05 fmol/10(5) cells/ 24 h; IR-ADM 1.20 +/- 0.09 fmol/10(5) cells/24 h; n = 5, mean +/- SEM). An analysis by reverse-phase high-performance liquid chromatography (HPLC) of the IR-ET in the culture medium showed a major immunoreactive peak in the position of ET-1. Reverse-phase HPLC of the IR-ADM in the medium showed three immunoreactive peaks, one of which eluted in the position of human ADM. Northern blot analysis showed the expression of ET-1 mRNA and ADM mRNA in the DLD-1 cells. Treatment with interferon-gamma (1-100 U/ml) for 24 h decreased the IR-ET levels in the culture medium but significantly increased IR-ADM levels. This study has shown the production and secretion of two vasoactive peptides, ET-1 and ADM, by DLD-1 colorectal adenocarcinoma cells. The secretion of IR-ET was decreased by treatment with interferon-gamma. These findings suggest possible pathophysiologic roles for ET-1 and ADM in colon mucosal epithelial cells and tumors derived from them.

Adenocarcinoma↗

PubMed1998

Expression of adrenomedullin and adrenomedullin mRNA in ectopic ACTH-secreting tumors.

OBJECTIVE: To study the expression of adrenomedullin, a potent vasodilator peptide originally isolated from a pheochromocytoma, in ectopic ACTH-secreting tumors. METHODS: Tumor tissue concentrations of adrenomedullin, calcitonin gene-related peptide, neuropeptide Y, endothelin-1, corticotropin-releasing hormone and ACTH were measured in three ectopic ACTH-secreting tumors by RIA. The expression of adrenomedullin mRNA was examined by northern blot analysis of tissue from one of the tumors. RESULTS: Immunoreactive adrenomedullin was detected in tumor tissues of three ectopic ACTH-secreting tumors (0.60-18.5 pmol/g wet weight). Calcitonin gene-related peptide, neuropeptide Y, endothelin-1 and corticotropin-releasing hormone were also detected in the tumor tissues. The tumor tissue concentrations of immunoreactive adrenomedullin were comparable to those of these four peptides, but much lower than those of ACTH. Northern blot analysis showed the expression of adrenomedullin mRNA in one tumor from which sufficient tissue was available for such study. The plasma concentration of immunoreactive adrenomedullin was increased in one patient (41.3 pmol/l, control 13.5 +/- 3.6 pmol/l, mean +/- S.D., n = 12). CONCLUSIONS: These results suggest that adrenomedullin is produced by ectopic ACTH-secreting tumors, together with other neuropeptides, and raise the possibility that adrenomedullin is related to the pathophysiology of these tumors.

Adrenocorticotropic Hormone↗

PubMed1998

Upregulation of atrial natriuretic peptide gene expression in remnant kidney of rats with reduced renal mass.

Atrial natriuretic peptide (ANP) is synthesized in the kidney but its physiologic significance there is unclear. To determine whether renal expression of the ANP gene is regulated, renal ANP mRNA expression was assessed in remnant kidneys after 5/6 nephrectomy in Munich-Wistar rats. In normal sodium intake groups, ANP mRNA expression in the remnant kidney was significantly increased by 5.0 +/- 0.8-fold (n = 7, mean +/- SEM) at 4 d when compared with sham-operated controls (n = 6, all sham-operated groups) (*P < 0.001 by Scheffe's test) and by 28.3 +/- 5.1-fold at 14 d. This latter response was markedly diminished to 7.6 +/- 2.1-fold (n = 7, versus sham) in rats maintained on a low sodium diet. At 4 d, on the other hand, no significant downregulation was observed with dietary sodium restriction. Because natriuretic peptides have previously been shown by us to play a major role in the adaptive responses of remnant nephrons to renal mass ablation, these data suggest that ANP of renal origin may contribute to the overall mechanism for enhancing sodium excretion in the face of declining nephron number.

Analysis of Variance↗

PubMed1997

Presence of adrenomedullin-like immunoreactivity in the human cerebrospinal fluid.

The presence of adrenomedullin-like immunoreactivity in the cerebrospinal fluid was studied by radioimmunoassay in 13 subjects with various neurological diseases. The concentrations of adrenomedullin-like immunoreactivity in the cerebrospinal fluid were 9.4 +/- 3.1 pmol/l (mean +/- SD, n = 13). Reverse-phase high performance liquid chromatography of the extract of the pooled cerebrospinal fluid showed that approximately 40% of the adrenomedullin-like immunoreactivity was chromatographically identical to human adrenomedullin (1-52). This is the first report that demonstrates the presence of adrenomedullin-like immunoreactivity in the human cerebrospinal fluid.

Adrenomedullin↗

PubMed1997

Specific adrenomedullin binding sites in the human brain.

Binding sites for adrenomedullin in human brain were investigated and characterized by radioligand binding. Specific binding sites for adrenomedullin were present in every region of human brain (cerebral cortex, cerebellum, thalamus, hypothalamus, pons and medulla oblongata) obtained at autopsy. Despite the homology with calcitonin gene-related peptide (CGRP), CGRP was a poor inhibitor of [125I]adrenomedullin binding (IC50 > 1 microM) compared with adrenomedullin(1-52) (IC50 = 1.2 +/- 0.5 nM, mean +/- SEM, n = 3). Three adrenomedullin fragments, adrenomedullin(1-12), adrenomedullin(22-52), and adrenomedullin(13-52), were also poor inhibitors of the binding (IC50 = 0.3 microM), suggesting that the whole molecule of adrenomedullin(1-52) is required for binding to the receptor. Scatchard plots of [125I]adrenomedullin binding in human brain (cerebral cortex) gave a dissociation constant of 0.17 +/- 0.03 nM and maximal binding of 99.3 +/- 1.9 fmol/mg protein (n = 5). These findings suggest that specific adrenomedullin binding sites that differ from the CGRP receptors exist in human brain. This indicates a possible novel neurotransmitter/neuromodulator role for adrenomedullin in human brain.

Adrenomedullin↗

PubMed1997

Urocortin expression in human pituitary gland and pituitary adenoma.

Urocortin is a recently identified neuropeptide of the CRF family in the mammalian brain, but its expression in human tissue has been little studied. In this study, we examined urocortin expression in human anterior pituitary gland and pituitary adenomas by RIA, high performance liquid chromatography, immunohistochemistry, messenger ribonucleic acid (mRNA) in situ hybridization, and reverse transcriptase-PCR. Immunoreactive urocortin concentrations in normal pituitary tissue extract were 103.25 +/- 39.05 ng/g wet wt (mean +/- SEM; n = 4), and their levels were all significantly higher than those in other portions of central nervous system of the same subjects. High performance liquid chromatography analysis of human pituitary extract demonstrated a single peak corresponding to that of the expected chromatographic mobility of synthetic human urocortin-(1-40). Urocortin-immunoreactive cells were detected in the anterior pituitary gland. Neither urocortin-immunoreactive nerve fibers nor cells were detected in the posterior lobe. Immunostaining in serial mirror tissue sections revealed that 76.55 +/- 3.06% of urocortin-immunoreactive cells expressed GH immunoreactivity, whereas 22.25 +/- 3.02% and less than 1% of urocortin-immunoreactive cells expressed PRL and ACTH, respectively. mRNA hybridization signals of urocortin were also detected in urocortin-immunopositive pituitary cells. The reverse transcriptase-PCR analysis demonstrated a 145-bp RNA band corresponding to that of the expected length of urocortin in all cases of normal pituitary glands examined (n = 3). We also immunostained urocortin in 52 cases of human anterior pituitary adenomas, including GH-producing adenomas (n = 14), ACTH-producing adenomas (n = 13), PRL-producing adenomas (n = 11), and nonfunctioning hormonally inactive adenomas (n = 14). No urocortin immunoreactivity was detected in these adenoma cells, except for one case of GH-producing adenoma and one case of nonfunctioning adenoma. We also performed mRNA in situ hybridization in 27 adenomas. No hybridization signals were detected in these adenomas, except in two cases. The results described above indicated that urocortin is synthesized in human anterior pituitary cells and may play an important role in biological features of normal pituitary gland, possibly as an autocrine or a paracrine regulator

Adenoma↗

PubMed1997

Cerebellin and cerebellin mRNA in the human brain, adrenal glands and the tumour tissues of adrenal tumour, ganglioneuroblastoma and neuroblastoma.

The expression of cerebellin and cerebellin mRNA was studied by radioimmunoassay and Northern blot analysis in the human brain, adrenal gland and the tumour tissues of adrenal tumour, ganglioneuroblastoma and neuroblastoma. Immunoreactive cerebellin was detected in every region of brain studied, with the highest concentrations found in the hemisphere of the cerebellum (424.2 +/- 12.6 pmol/g wet weight, n = 6, mean +/- S.E.M.) and the vermis of the cerebellum (256.8 +/- 30.5 pmol/g wet weight). Immunoreactive cerebellin was also detected in the pituitary (8.2 +/- 1.8 pmol/g wet weight), the spinal cord (3.3 +/- 0.3 pmol/g wet weight) and the normal parts of adrenal glands (2.98 +/- 0.37 pmol/g wet weight, n = 9) and some tumour tissues, such as phaeochromocytomas, cortisol-producing adrenocortical adenomas, ganglioneuroblastomas and neuroblastomas. Northern blot analysis showed that cerebellin mRNA was highly expressed in the hemisphere and vermis of the cerebellum. Cerebellin mRNA was also expressed in other regions of the brain and the tumour tissues of phaeochromocytoma, cortisol-producing adrenocortical adenoma, ganglioneuroblastoma and neuroblastoma. Immunocytochemistry of the normal adrenal gland showed that immunoreactive cerebellin was localized in the adrenal medulla. The present study has shown the expression of cerebellin and cerebellin mRNA, not only in the cerebellum but also in other regions of the brain and some tumours, such as cortisol-producing adrenocortical adenoma, phaeochromocytoma and neuroblastoma. These findings suggest possible pathophysiological roles of cerebellin peptides, not only in the cerebellum, but also in the extra-cerebellar tissues.

Adenoma↗

PubMed1997

Immunoreactive adrenomedullin in human adrenal glands and adrenal tumors.

Adrenomedullin is a potent vasodilator peptide that was isolated from human pheochromocytoma. We developed a sensitive and specific radioimmunoassay for adrenomedullin and studied the presence of adrenomedullin in human adrenal glands and adrenal tumors, including pheochromocytoma. High concentrations of immunoreactive adrenomedullin were found in normal parts of adrenal glands (cortex and medulla) (12.6 +/- 1.0 pmol/g wet wt, N = 7, mean +/- SEM). High concentrations of immunoreactive adrenomedullin were also present in the tumor tissues of pheochromocytoma (4.5 +/- 1.5 pmol/g wet wt, N = 11). Immunoreactive adrenomedullin was detected in some adrenocortical tumors, but these concentrations were much lower than those in the normal adrenal glands and pheochromocytomas. Reverse phase high-performance liquid chromatography of the normal adrenal gland and pheochromocytoma showed a peak eluting in the position of synthetic adrenomedullin 1-52. The present study has shown the presence of high concentrations of immunoreactive adrenomedullin in the normal adrenal glands and pheochromocytomas.

Adenocarcinoma↗

PubMed1996

Urinary immunoreactive brain natriuretic peptide in patients with renal disease.

Urinary immunoreactive brain natriuretic peptide (BNP) was studied by radioimmunoassay in patients with renal disease. Urinary immunoreactive human BNP excretion measured in 11 normal subjects was 3.82 +/- 0.62 pmol/day (mean +/- SEM). Significantly increased 24-h urinary secretion of immunoreactive human BNP was noted in patients with chronic renal failure (11.07 +/- 1.73 pmol/day, n = 9, P < 0.05 to normal subjects). A significant correlation was noted between 24-h urinary excretion of immunoreactive human BNP and creatinine clearance in patients with various renal diseases (r = -0.43, P < 0.01, n = 45). Gel chromatography of the urine extracts obtained from normal subjects and patients with chronic renal failure showed multiple immunoreactive peaks; two eluting earlier, one in the position of human BNP-32 and others eluting later. Reverse-phase high-performance liquid chromatography of the urine extracts showed a peak in the position of human BNP-32 and a peak eluting earlier. These findings indicate that: (1) immunoreactive human BNP is present in human urine; (2) urinary immunoreactive human BNP consists of multiple components, i.e., human BNP-32 itself or a substance very similar to it, smaller molecular forms which are probably metabolic products of human BNP-32, and larger molecular forms; and (3) 24-h urinary excretion of immunoreactive human BNP is increased in patients with renal dysfunction.

Adolescent↗

PubMed1996

Immunocytochemical localization of adrenomedullin-like immunoreactivity in the human hypothalamus and the adrenal gland.

Adrenomedullin is a potent vasodilator peptide that was isolated from pheochromocytoma. Localization of adrenomedullin-like immunoreactivity was studied by immunocytochemistry in the human hypothalamus and adrenal gland. Adrenomedullin-immunoreactive cell bodies were found in the paraventricular, supraoptic and infundibular nuclei of the hypothalamus. Both magnocellular and parvocellular cells of the paraventricular nucleus were positively immunostained. Adrenomedullin-like immunoreactivity was localized in the adrenal medulla. No positive immunostaining was observed in the vascular endothelium, vascular smooth muscle cell or adrenal cortex. The preabsorption of the antiserum with synthetic human adrenomedullin (1-52) abolished the immunostaining. These findings indicate that adrenomedullin-like immunoreactivity is localized in the paraventricular, supraoptic and infundibular nuclei as well as in the adrenal medulla, and suggest that adrenomedullin acts as a neurotransmitter, a neuromodulator or a neurohormone in the human hypothalamus.

Adrenal Glands↗

PubMed1996

Immunoreactive brain natriuretic peptide in human adrenal glands and adrenal tumors.

The presence of brain natriuretic peptide (BNP) in tissues of human adrenal glands and adrenal tumors was investigated by radioimmunoassay. Immunoreactive BNP concentrations were 0.203 +/- 0.061 pmol/g wet tissue (mean +/- SEM) in normal parts of adrenal glands (cortex and medulla, N = 8), 0.205 +/- 0.037 pmol/g wet tissue in pheochromocytomas (N = 8), 0.230 +/- 0.062 pmol/g wet tissue in aldosteronomas (N = 11) and 0.180 +/- 0.054 pmol/g wet tissue in adrenocortical adenomas with Cushing's syndrome (N = 4). Sephadex G-50 superfine column chromatography and reverse-phase high-performance liquid chromatography showed that most (> 70%) of the immunoreactive BNP in the normal part of adrenal glands was eluted in the position of human BNP-32. Sephadex G-50 superfine column chromatography of immunoreactive BNP in the pheochromocytoma and aldosteronoma showed four peaks: one in the position of gamma-BNP, one in the position of BNP-32, one between gamma-BNP and BNP-32 and one in the smaller molecular weight region. The present study has shown that immunoreactive BNP is present both in normal human adrenal glands and in adrenal tumors. Multiple molecular forms of BNP were found to be present in the tumor tissues of pheochromocytoma and aldosteronoma.

Adrenal Gland Neoplasms↗

PubMed1995

Decrease in cerebellin and corticotropin-releasing hormone in the cerebellum of olivopontocerebellar atrophy and Shy-Drager syndrome.

Four neuropeptides; cerebellin, corticotropin-releasing hormone (CRH), neuropeptide Y and somatostatin were studied by radioimmunoassay in the postmortem human brains obtained from three patients with olivopontocerebellar atrophy (OPCA) and one with Shy-Drager syndrome. Significant decreases in cerebellin and CRH concentrations were found in the cerebellar hemisphere of these diseases compared with controls. These findings suggest important pathophysiological roles of cerebellin and CRH in these cerebellar diseases. Such significant decreases were not found in neuropeptide Y and somatostatin.

Adult↗