676
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Fukuda T, Baba Y, Tanaka M, Ishibashi H, Hirata Y, Okamura T, Kudo J, Niho Y, Yamanaka M. [Severe alcoholic cirrhosis associated with spur cell anemia and DIC]. FUKUOKA IGAKU ZASSHI = HUKUOKA ACTA MEDICA 1991; 82:398-402. [PMID: 1885127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A 29-year-old male who had a 15-year history of alcohol drinking was admitted with a 5-month history of jaundice in July 1989. Laboratory examinations revealed that he had hemolytic anemia and severe liver damage. Erythrocytes of peripheral blood showed typical spiculated cells on light microscopic and scanning electron microscopic studies. Free-cholesterol/phospholipid ratio of the erythrocyte membrane was elevated, and the level of chenodeoxycholic acid increased in serum. The patient was diagnosed as having advanced alcoholic cirrhosis associated with spur cell anemia. Two months after admission, he was complicated with chronic disseminated intravascular coagulopathy (DIC). Anemia, hepatic failure and DIC progressed, and the patient died six months after admission. The mechanism of the formation of spur cells was discussed.
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677
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Hirata Y, Matsuoka H, Hayakawa H, Sugimoto T, Suzuki E, Sugimoto T, Kangawa K, Matsuo H. Role of endogenous atrial natriuretic peptide in regulating sodium excretion in spontaneously hypertensive rats. Effects of neutral endopeptidase inhibition. Hypertension 1991; 17:1025-32. [PMID: 1828456 DOI: 10.1161/01.hyp.17.6.1025] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To explore whether pathophysiological plasma levels of atrial natriuretic peptide (ANP) actually involve sodium excretion in spontaneously hypertensive rats (SHR), we examined the in vivo and ex vivo effects of ANP and an endopeptidase inhibitor, thiorphan, on urinary sodium excretion and the elimination rate of ANP. We found the following: 1) The basal plasma ANP level was higher in 16-week-old SHR than in Wistar-Kyoto (WKY) rats (109 +/- 10 [SEM] versus 63 +/- 4 pg/ml, p less than 0.001). Thiorphan (30 mg/kg i.v.) significantly increased plasma ANP by 60% in both SHR and WKY rats. However, increases in urinary sodium excretion (+290% versus +130%, p less than 0.05) and cyclic GMP (+160% versus +60%, p less than 0.05) were greater in SHR than in WKY rats. Urinary excretion of ANP was markedly increased by thiorphan, and its increase was greater in SHR than in WKY rats. 2) The thiorphan-induced natriuresis was substantially attenuated by antiserum for ANP but not by a bradykinin receptor antagonist. 3) Isolated SHR kidneys excreted 50% less sodium than WKY rat kidneys at perfusion pressures of 100 and 160 mm Hg (p less than 0.05). Urinary sodium excretion was increased at the perfusate ANP level of 100 pg/ml, a concentration similar to the SHR plasma ANP (+70% at 160 mm Hg). 4) After bolus administration of ANP to the isolated kidney, the ANP concentration of the recirculating perfusate decreased rapidly in a log-linear fashion.(ABSTRACT TRUNCATED AT 250 WORDS)
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678
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Hayashi K, Dojo S, Nakashima K, Nishio E, Kurushima H, Saeki M, Amioka H, Hirata Y, Ohtani H, Hiraoka M. Analysis of neutral amino acid transport systems in the small intestine: a study of brush border membrane vesicles. GASTROENTEROLOGIA JAPONICA 1991; 26:287-93. [PMID: 1909674 DOI: 10.1007/bf02781916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Transport of L-proline, L-leucine and L-cysteine was studied in brush border membrane vesicles prepared from guinea pig ileum. Concentrative transport of L-proline, L-leucine and L-cysteine was obtained in the presence of an Na+ gradient from, outside to inside of the vesicles, which indicated contribution of either system A (alanine-preferring) or system ASC (alanine-, serine- and cysteine-preferring) to the transport. When Na+ was replaced by Li+, L-leucine and L-cysteine maintained the same concentrative transport. However, the concentrative transport of L-proline was markedly decreased by Li+ -for-Na+ substitution. Strong exchange properties of L-leucine transport via system L (leucine-preferring) was observed with brush border membrane vesicles, in which preloaded L-methionine could be exchanged with labeled L-leucine added outside the vesicles. These results suggest that the small intestine of the guinea pig possesses classical neutral amino acid transport systems such as systems A, ASC and L.
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679
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Maruta T, Narabayashi I, Suematsu T, Hirata Y, Ueda E, Ogawa K, Mieda C, Okada K, Ikeda Y, Hirota S. [Clinical value of Gd-DTPA enhanced MRI of pulmonary and mediastinal tumors]. NIHON IGAKU HOSHASEN GAKKAI ZASSHI. NIPPON ACTA RADIOLOGICA 1991; 51:504-15. [PMID: 1651471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gd-DTPA (Gd) enhanced Magnetic Resonance (MR) early images and delayed images of 28 patients with pulmonary or mediastinal tumors were analyzed and compared with the computed tomography scans and the plain MR images. Numbers of relative signal intensity of the tumors, secondary lesions (adjacent pneumonia or collapse) and pleural effusions were calculated and graphed on time intensity curves. Gd-enhanced MR early images were more useful than other methods in delineating viable areas from necrotic areas. However, Gd-enhanced MR delayed images better delineated margins of necrotic areas than Gd-enhanced MR early images did in some cases. In distinguishing tumors from secondary lesions, Gd-enhanced MR early images were the most useful, too. We considered Gd gradually penetrated into pleural effusions after intravenous administration, just in the same way into necrotic areas. Therefore pleural effusions showed very high intensity on Gd-enhanced MR delayed images. Time intensity curves of the tumors and pleural effusions showed characteristic patterns, but those of secondary lesions showed different patterns among the individual cases. We presumed this was due to the variances of the water and fibrous components among them.
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680
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Marumo F, Tomita K, Sasaki S, Akiba T, Hirata Y. Endothelin and renal failure. Int J Artif Organs 1991; 14:259-61. [PMID: 1864648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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681
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Marumo F, Tomita K, Sasaki S, Akiba T, Hirata Y. Endothelin and Renal Failure. Int J Artif Organs 1991. [DOI: 10.1177/039139889101400502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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682
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Shichiri M, Hirata Y, Nakajima T, Ando K, Imai T, Yanagisawa M, Masaki T, Marumo F. Endothelin-1 is an autocrine/paracrine growth factor for human cancer cell lines. J Clin Invest 1991; 87:1867-71. [PMID: 2022753 PMCID: PMC295314 DOI: 10.1172/jci115210] [Citation(s) in RCA: 157] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We studied whether a novel vasoconstrictor peptide, endothelin-1 (ET-1), is synthesized by and released from human carcinoma cell lines, and whether ET-1 stimulates proliferation of these tumor cells. ET-1-like immunoreactivity was released from both HeLa and HEp-2 cells as a function of time. Reverse-phase HPLC of the conditioned media from HeLa cells revealed a major peak coeluting with standard ET-1. Northern blot analysis demonstrated the expression of mRNA for ET-1 precursor in both tumor cell lines. Both cell lines contained a single class of specific binding sites for ET-1. ET-1 dose-dependently induced increases in cytosolic free Ca2+ concentration in fura-2-loaded tumor cells, whose effect was completely abolished by chelating extracellular Ca2+ or by Ca(2+)-channel blocker. ET-1 stimulated proliferation of the quiescent cell lines in a dose-dependent manner, whose effect was inhibited by Ca(2+)-channel blocker. Polyclonal antibody for ET-1 inhibited proliferation of these cell lines, whereas nonimmune serum had no effect. These results demonstrate that ET-1 is synthesized by and released from human epithelial carcinoma cell lines, and that exogenous and endogenous ET-1 stimulates proliferation of the cells possibly through Ca2+ influx, suggesting its role as an autocrine/paracrine growth factor for certain tumor cells.
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683
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Ueda F, Watanabe M, Hirata Y, Kyoi T, Kimura K. Changes in cyclic AMP content of rat gastric mucosa induced by ulcerogenic stimuli--in relation to the antiulcer activity of irsogladine maleate. JAPANESE JOURNAL OF PHARMACOLOGY 1991; 55:493-9. [PMID: 1653374 DOI: 10.1254/jjp.55.493] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Changes in the cyclic AMP (cAMP) content of the gastric mucosa induced by ulcerogenic stimuli were investigated in rats. Ligation of the pylorus for 5 hr produced no glandular mucosal lesion, but increased the cAMP content in the fundus and antrum. Aspirin produced glandular mucosal lesions in the pylorus-ligated rats and caused an increase of the cAMP content in the fundus and a decrease in the antrum. Irsogladine maleate (IM), an antiulcer agent, inhibited both the changes in the cAMP content and the mucosal damage induced by aspirin. IM increased the cAMP content in both regions, especially the antrum, in normal rats. Dibutyryl cAMP (dbcAMP) given orally prevented the gastric mucosal lesions induced by aspirin without affecting gastric secretion. These results suggest that 1) the changes in the cAMP content of the fundus and antrum induced by aspirin may be associated with the formation of glandular mucosal damage, 2) the antiulcer activity of IM may be related to an increase of the cAMP content in mucous cells, and 3) dbcAMP given orally may penetrate into the surface mucous cells and activate defensive functions. Thus, cAMP in the mucous cells may protect the gastric mucosa.
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684
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Osawa N, Hirata Y, Akiyama T, Hiraishi S, Yashiro K. Possible role of Streptococcus pyogenes in mucocutaneous lymph node syndrome XIII. No recovery of beta-hemolytic streptococci from pharynx of MCLS patients. ACTA PAEDIATRICA JAPONICA : OVERSEAS EDITION 1991; 33:166-71. [PMID: 1957640 DOI: 10.1111/j.1442-200x.1991.tb01537.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Lack of recovery of beta-hemolytic streptococci from the throat of 80 patients finally diagnosed as mucocutaneous lymph node syndrome was again confirmed, although alpha-hemolytic streptococci were consistently isolated from all patients but one. The implications of these findings were discussed, particularly in terms of the possible role of Streptococcus pyogenes in the pathogenesis of this disease.
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685
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Takahashi C, Ujihara N, Babazono T, Yokoyama H, Nakanishi K, Tomonaga O, Sanaka T, Hirata Y. Analysis of the clinical course of 130 Japanese non-insulin-dependent diabetic patients undergoing dialysis. THE JOURNAL OF DIABETIC COMPLICATIONS 1991; 5:171-2. [PMID: 1770035 DOI: 10.1016/0891-6632(91)90062-t] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To clarify the characteristics of diabetic nephropathy (DN) in Japanese patients with non-insulin-dependent diabetes (NIDDM), we analyzed the clinical course of 130 such patients who began dialysis treatment due to DN between 1978 and 1988 at the Diabetes Center of Tokyo Women's Medical College. Analysis of the clinical course prior to attending the Diabetes Center revealed that 64 (49.2%) of the patients neglected or discontinued their initial treatment for diabetes until the development of diabetic complications because of the lack of symptoms. The average duration of untreated diabetes in these patients was 10.7 +/- 4.6 years. The biggest problem for NIDDM patients was the absence of symptoms until the development of diabetic complications.
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686
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Taguchi T, Suita S, Hirata Y, Ishii E, Ueda K. Carcinoma of the colon in children: a case report and review of 41 Japanese cases. J Pediatr Gastroenterol Nutr 1991; 12:394-9. [PMID: 2072235 DOI: 10.1097/00005176-199104000-00020] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We report a case of sigmoid colon carcinoma in a 14-year-old girl. She had been suffering from several nonspecific abdominal symptoms for about 1 year before a definite diagnosis was made. While undergoing an operation, the main tumor was found to be unresectable. She died of Candida-induced septicemia on the 26th day after the operation. There have been 40 cases of colon carcinoma reported in the Japanese literature in patients 15 years of age or younger. We reviewed the 40 Japanese cases along with our case, and compared these to other children and adult studies. The prognosis is quite unfavorable in children because of the poor histological character and the delayed diagnosis. Serum carcinoembryonic antigen measurement might be one means for early diagnosis.
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687
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Ohta K, Hirata Y, Shichiri M, Ichioka M, Kubota T, Marumo F. Cisplatin-induced urinary endothelin excretion. JAMA 1991; 265:1391-2. [PMID: 1999877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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688
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Hayashi K, Dojo S, Hirata Y, Ohtani H, Nakashima K, Nishio E, Kurushima H, Saeki M, Kajiyama G. Metabolic changes in LDL receptors and an appearance of scavenger receptors after phorbol ester-induced differentiation of U937 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1082:152-60. [PMID: 2007178 DOI: 10.1016/0005-2760(91)90189-o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Metabolic changes in lipoprotein receptors after cell differentiation were investigated using U937 cells, a human tumor cell line with monoblastic characteristics. After inducing the differentiation of U937 cells into monocyte-macrophage-like cells using TPA (12-tetradecanoyl-phorbol-13-acetate), the incorpotation of [14C]oleate into cellular cholesteryl [14C]oleate was increased in comparison with U937 cells when incubated with r-beta VLDL, h-VLDL or h-LDL. A marked down-regulation of LDL receptors was observed in U937 cells upon addition of 25-hydroxycholesterol. However, this down-regulation of LDL receptors was poor in monocyte-macrophage-like cells that had been induced to differentiate from U937 cells with TPA. Acyl coenzyme A:cholesterol acyltransferase activity was increased after TPA-induced differentiation of U-937 cells. The incorporation of [14C]oleate into cellular cholesteryl [14C]oleate was also increased when incubated with acetylated h-LDL in monocyte-macrophage-like cells in comparison with U937 cells. These results suggest that a poor down-regulation of LDL receptors, which is attributable to increased acyl coenzyme A:cholesterol acyltransferase activity, and scavenger receptors are induced and that these metabolic changes in lipoprotein receptors and an increased acyl coenzyme A:cholesterol acyltransferase activity contribute to cholesterol ester accumulation in monocyte-macrophage-like cells.
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689
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Fuji T, Fujiwara K, Hirata Y, Hijikata T, Saito S, Ono K. In vivo evaluation of fixation of metal implants coated by melt-sprayed alumina--experiments in rabbit. MEDICAL JOURNAL OF OSAKA UNIVERSITY 1991; 40:19-28. [PMID: 1369652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Skeletal fixation characteristics of the stainless steel implants coated by 60 microns thick porous alumina layer using a flame spray method were evaluated in vivo for the duration of up to 12 weeks. Surface roughness of the implants appeared to be the determining factor for the fixation characteristics, irrespective of the implant materials.
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690
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Eguchi S, Kozuka M, Hirose S, Ito T, Hirata Y, Marumo F, Hagiwara H. Identification of G protein-coupled endothelin receptors in cultured bovine endothelial cells. Biochem Biophys Res Commun 1991; 174:1343-6. [PMID: 1847632 DOI: 10.1016/0006-291x(91)91570-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Autocrine and paracrine regulation of vascular endothelial cells by endothelins has been postulated and has been the target of many recent investigations. In the present study, we demonstrated, by affinity labeling, the presence of endothelin-1- and endothelin-3-specific receptors on cultured bovine endothelial cells that secrete endothelin; the endothelin-3 receptor was the major form. Analysis using the GTP analogue guanosine 5'-O- (thiotriphosphate) indicated that these receptors are coupled to G proteins.
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691
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Fukuda T, Okamura T, Doi K, Yamauchi Y, Toyoshima H, Hirata Y, Nagasawa K, Nishina Y. [A case of allergic granulomatous angitis with factor VIII inhibitor]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 1991; 80:274-5. [PMID: 1907634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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692
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Hirata Y. [Insulin autoimmune syndrome]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1991; 49 Suppl:703-10. [PMID: 2033867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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693
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Tasaka Y, Matsumoto H, Inoue Y, Mochizuki N, Hirata Y. Plasma insulin and glucagon and their release from pancreatic islet in hyperosmolar diabetic rat. ENDOCRINOLOGIA JAPONICA 1991; 38:53-9. [PMID: 1833178 DOI: 10.1507/endocrj1954.38.53] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In order to investigate the metabolic abnormalities in hyperosmolar diabetes from the viewpoint of insulin or glucagon, experimental hyperosmolar diabetes was produced by a combination of cortisol injection and water deprivation or only by the latter in streptozotocin-induced moderately hyperglycemic rat. They had a high blood glucose level and high plasma osmotic pressure. Fasting plasma insulin tended to decrease in the dehydrated state whether diabetic or not. Fasting plasma glucagon was increased to 0.047 +/- 0.009 nmol/l (P less than 0.05) in the non-diabetic dehydrated state (normal 0.026 +/- 0.004 nmol/l), and a similar high level of plasma glucagon was observed in the dehydrated diabetic rat (0.052 +/- 0.020 nmol/l), especially after cortisol treatment. In isolated rat islet, insulin released from the dehydrated diabetic rat at a high concentration of glucose was to some extent lower than that of diabetic rat, and released IRG vice versa. The insulin:glucagon ratio in the presence of high glucose was significantly lower in the dehydrated diabetic rat than in the normal rat (P less than 0.01). In the diabetic rat this ratio was not significantly different. This finding was also consistent with the results of in vivo experiments. Thus more catabolic hormonal changes were found in in vivo and in vitro studies in the hyperosmolar diabetic rat.
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694
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Otani T, Hirata Y. [Maturity-onset diabetes of the young (MODY)]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1991; 49 Suppl:405-11. [PMID: 2033831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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695
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Hirata Y, Ishii M, Fukui K, Hayakawa H, Suzuki E, Sugimoto T, Kimura K, Matsuoka H, Sugimoto T. Differential effects of atrial natriuretic peptide and dopamine on urinary protein excretion in chronic glomerulonephritis. Clin Sci (Lond) 1991; 80:131-6. [PMID: 1848164 DOI: 10.1042/cs0800131] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
1. To examine whether or not atrial natriuretic peptide-induced proteinuria simply results from increases in urine flow or glomerular filtration rate, we infused dopamine (1 microgram min-1 kg-1) and alpha-human atrial natriuretic peptide (0.025 microgram min-1 kg-1) into nine patients with chronic glomerulonephritis and nine essential hypertensive patients without renal damage, and compared the effects of the two agents on renal function and urinary protein excretion. 2. In patients with chronic glomerulonephritis, dopamine infusion significantly increased urinary sodium excretion (+59%), renal blood flow (+20%) and creatinine clearance (+14%). However, urinary protein excretion was not changed. Addition of atrial natriuretic peptide to the dopamine infusion further increased urinary sodium excretion and maintained creatinine clearance at the same level. In contrast to the infusion of dopamine alone, atrial natriuretic peptide markedly increased urinary protein excretion (77 versus 229 mg min-1 m2, P less than 0.02). Furthermore, the addition of atrial natriuretic peptide elevated the urinary protein/creatinine ratio (1.55 versus 5.35, P less than 0.05), while dopamine alone did not (1.55 versus 1.45, not significant). 3. In essential hypertensive patients, dopamine and dopamine plus ANP showed renal effects similar to those of chronic glomerulonephritis; however, the urinary excretion of protein was not changed significantly. 4. These results suggest that atrial natriuretic peptide may increase urinary protein excretion mainly by increasing the permeability of the damaged glomeruli to protein rather than by simply increasing urine flow or glomerular filtration. Possible mechanisms underlying the proteinuria-increasing effects of atrial natriuretic peptide are discussed.
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696
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Takahashi Y, Hirata Y, Yokoyama S, Ishii N, Nunes L, Lue TF, Tanagho EA. Loss of penile erectile response to intracavernous injection of acetylcholine in castrated dog. TOHOKU J EXP MED 1991; 163:85-91. [PMID: 2048126 DOI: 10.1620/tjem.163.85] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Castrated dogs showed a slightly weak erectile response to cavernous nerve stimulation compared with normal dogs. Intracavernous injection of acetylcholine induced a dose-dependent increase of intracavernous pressure in normal dogs, however, there was almost no penile response in castrated dogs. Histological study showed a significant higher ratio of collagen tissue/smooth muscle in the corpus cavernosum of castrated dogs, but no difference in acetylcholine-esterase staining and the number of endothelial cells lining the sinusoidal spaces between castrated and normal dogs. These results indicate that the corpus cavernosum of castrated dogs nearly lost responsiveness to acetylcholine probably due to a high ratio of collagen/smooth muscle fibers and that there are different mechanisms for erectile response to nerve stimulation and intracavernous injection of acetylcholine.
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697
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Toyo-oka T, Aizawa T, Suzuki N, Hirata Y, Miyauchi T, Shin WS, Yanagisawa M, Masaki T, Sugimoto T. Increased plasma level of endothelin-1 and coronary spasm induction in patients with vasospastic angina pectoris. Circulation 1991; 83:476-83. [PMID: 1825037 DOI: 10.1161/01.cir.83.2.476] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To elucidate the pathogenic contribution of a potent vasoconstrictor, endothelin-1, to coronary artery spasm, we provoked spasm with intracoronary administration of acetylcholine or ergonovine and performed sensitive immunoassays of plasma levels of endothelin-1 and atrial natriuretic factor (ANF) in the peripheral vein and coronary sinus of patients with a tentative diagnosis of vasospastic angina (VSA, n = 19). The validity of coronary sinus blood sampling was verified by simultaneous measurement of the ANF level. The plasma endothelin-1 levels in venous and coronary sinus blood of the spasm-provoked patients (n = 12) were 1.71-fold and 2.16-fold higher, respectively, than those of nonprovoked cases (n = 5, p less than 0.01). During left coronary spasm, the endothelin-1 level in coronary sinus transiently decreased from 2.27 +/- 0.14 to 1.76 +/- 0.14 pg/ml (p less than 0.01) and returned to the control level (1.98 +/- 0.20 pg/ml) after the spasm resolved, whereas the change was equivocal during right coronary spasm. In contrast, the patients in whom spasm was not provoked showed no changes and maintained low endothelin-1 levels both before and after the maximal provocation (0.90 +/- 0.13 versus 0.90 +/- 0.13 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)
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698
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Emori T, Hirata Y, Kanno K, Ohta K, Eguchi S, Imai T, Shichiri M, Marumo F. Endothelin-3 stimulates production of endothelium-derived nitric oxide via phosphoinositide breakdown. Biochem Biophys Res Commun 1991; 174:228-35. [PMID: 1846538 DOI: 10.1016/0006-291x(91)90510-e] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cultured bovine endothelial cells (EC) have specific receptors for endothelin (ET)-3 functionally coupled to phosphoinositide breakdown. We studied whether ET-3 stimulates synthesis of nitric oxide (NO), an endothelium-derived relaxing factor that activates soluble guanylate cyclase in EC, and whether the ET-3-induced NO formation involves G-proteins. ET-3 dose-dependently stimulated production of intracellular cGMP in EC, of which effects were abolished by pretreatment with NG-monomethyl L-arginine, an inhibitor of NO synthesis, and methylene blue, an inhibitor of soluble guanylate cyclase. The stimulatory effects of ET-3 on cGMP production, inositol trisphosphate formation and increase in cytosolic free Ca2+ concentration were similarly blocked by pretreatment with pertussis toxin (PTX). These data suggest that ET-3 induces synthesis of NO mediated by phosphoinositide breakdown via PTX-sensitive G-protein in EC.
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699
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Hirata Y. [Clinical significance and therapeutic application of atrial natriuretic peptides]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 1991; 80:112-8. [PMID: 1850778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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700
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Ota S, Hirata Y, Sugimoto T, Kohmoto O, Hata Y, Yoshiura K, Nakada R, Terano A, Sugimoto T. Endothelin-1 secretion from cultured rabbit gastric epithelial cells. J Cardiovasc Pharmacol 1991; 17 Suppl 7:S406-7. [PMID: 1725393 DOI: 10.1097/00005344-199100177-00114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It has been shown that endothelin-1 (ET-1) is synthesized in various extraendothelial tissues. Although ET-1 has been reported to have potent ulcerogenic action in the stomach, the synthesis and physiological roles of ET-1 in the gastric mucosa are poorly understood. The aim of the present study was to investigate whether or not cultured gastric epithelial cells secrete ET-1 and possess autocrine functions. Gastric epithelial cells from rabbits were cultured in medium supplemented with 10% FBS after isolation. ET-1 was extracted by C18 columns from serum-free culture media and measured by radioimmunoassay (RIA). Effects of ET-1 on the intracellular concentration of calcium of the cultured cells were examined with Indo-1. Prostaglandin E2 (PGE2) was measured by RIA. Primary cultures of gastric epithelial cells were mainly composed of mucous cells. ET-1 was detected in the culture medium by RIA, and 70 pg/10(6) cells/24 h of ET-1 was secreted by cultured cells. Tumor growth factor-beta (4 ng/ml) and thrombin (8 U/ml) significantly increased ET-1 secretion. Exogenously administered ET-1 up to 10(-6) M neither modulated the intracellular calcium concentration nor affected PGE2 release by these cells. These results suggest that gastric mucous cells in culture secrete ET-1. Further studies are needed to explore the possible involvement of such paracrine function in the reported ulcerogenic action of ET-1.
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