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1.
J Hum Hypertens ; 31(7): 450-456, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28032630

RESUMEN

It is still controversial whether treatment with renin-angiotensin system (RAS) inhibitors reduces the risk of incident atrial fibrillation (AF). This longitudinal observational study was performed to investigate the confounder-independent effects of RAS inhibitors on new-onset AF in hypertensive patients. Among 1263 consecutive hypertensive patients who underwent echocardiography, 964 eligible patients (mean age, 63 years) were enrolled as the study population. Forty-nine patients developed new-onset AF during the follow-up period (mean: 4.6 years). Kaplan-Meier analysis showed that the cumulative AF event rate was lower in patients receiving RAS inhibitors than in patients without these drugs, but the difference between these two groups was not significant (P=0.057). Since the use of RAS inhibitors was influenced by concomitant diabetes, chronic kidney disease and left ventricular hypertrophy, propensity score matching (1:1) was employed to minimize the influence of selection bias for RAS inhibitors. Clinical and echocardiographic parameters showed no significant differences between the propensity score-matched groups with and without RAS inhibitor therapy (both n=326), but the cumulative AF event rate was significantly lower in the group receiving RAS inhibitors (P=0.013). Univariate and multivariate Cox regression analyses also revealed that RAS inhibitor therapy was associated with a significantly lower risk of new-onset AF during the follow-up period. In conclusion, this propensity score matching study demonstrated that the incidence of new-onset AF was lower in hypertensive patients receiving RAS inhibitor therapy.


Asunto(s)
Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Fibrilación Atrial/prevención & control , Hipertensión/complicaciones , Sistema Renina-Angiotensina/efectos de los fármacos , Anciano , Antagonistas de Receptores de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Fibrilación Atrial/etiología , Femenino , Humanos , Hipertensión/tratamiento farmacológico , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Puntaje de Propensión
2.
Diabetes ; 35(12): 1374-82, 1986 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3770314

RESUMEN

The relationship between apolipoprotein E (apoE) polymorphism and plasma lipids and hyperlipemia was investigated in 105 male type II diabetics and 111 male nondiabetics. ApoE phenotypes were determined by a one-dimensional rapid flat gel isoelectric focusing method as described previously. The apoE phenotype frequency in diabetics was similar to that in nondiabetics. The frequency of hyperlipemia was higher in diabetics (56.2%) than in nondiabetics (32.4%). It was highest in the apoE3/2 group of diabetics and nondiabetics, followed by the apoE4/3 and apoE3/3 groups in the order described, indicating that the susceptibility to hyperlipemia differs among the apoE phenotype groups. ApoE3/2 diabetics had significantly higher levels of apoE and very-low-density lipoprotein (VLDL) cholesterol (chol)/VLDL triglyceride (TG) ratios than apoE3/3 diabetics. The effects of diabetes mellitus on plasma lipid levels differed among the various apoE phenotype groups: i.e., plasma total chol and low-density lipoprotein (LDL) chol increased only in apoE3/2 and apoE4/3 diabetics and plasma high-density lipoprotein chol decreased only in apoE3/3 diabetics, as compared with the corresponding apoE phenotype groups of nondiabetics, whereas plasma TG, VLDL TG, and VLDL chol increased in the three apoE phenotype diabetics. Furthermore, an increase of apoEII:apoEIII ratio was observed in apoE3/3 diabetics, particularly in those with hypertriglyceridemia. This study has also shown that the increased apoEII:apoEIII ratio is due to increased sialation of apoE based on the study of sialidase digestion of apo VLDL.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Apolipoproteínas E/genética , Diabetes Mellitus Tipo 2/complicaciones , Hiperlipidemias/complicaciones , Adulto , Apolipoproteínas E/aislamiento & purificación , Diabetes Mellitus Tipo 2/genética , Humanos , Hiperlipidemias/genética , Focalización Isoeléctrica , Lípidos/sangre , Lipoproteínas/sangre , Lipoproteínas VLDL/sangre , Masculino , Persona de Mediana Edad , Fenotipo , Polimorfismo Genético
3.
Diabetes ; 36(11): 1301-6, 1987 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3666320

RESUMEN

The apolipoprotein E (apoE) phenotype and allele frequencies were examined in type II (non-insulin-dependent) diabetic patients with normolipidemia (n = 134) and hypercholesterolemia (type IIa hyperlipoproteinemia, n = 35; type IIb hyperlipoproteinemia, n = 42). The frequencies of apoE4-present phenotypes (apoE4/3, apoE4/4, and apoE4/2) were highest in the type IIa group (51.4%), followed by the type IIb group (38.1%) and the normolipidemic group (16.4%), respectively, whereas the frequency of the most common phenotype, apoE3/3, was lowest in the type IIa group (48.6%), followed by the type IIb group (61.9%) and the normolipidemic group (79.9%), respectively. There were significant differences in the apoE phenotype frequencies between the normolipidemic group and the type IIa and IIb groups. The frequency of the epsilon 4 allele was significantly higher in the type IIa (28.6%) and IIb (20.2%) groups than in the normolipidemic group (8.9%), whereas the frequency of the epsilon 3 allele was significantly lower in the type IIa (71.4%) and IIb (78.6%) groups than in the normolipidemic group (89.2%). The frequency of the epsilon 2 allele tended to be lower in diabetic patients with hypercholesterolemia. In addition, these frequencies were also examined in nondiabetic subjects (n = 59). The frequency of the epsilon 4 allele tended to be higher in hypercholesterolemic diabetic subjects (24.1%) than in hypercholesterolemic nondiabetic subjects (15.3%). These data suggest that diabetic patients with the epsilon 4 allele may be more susceptible to hypercholesterolemia than diabetic patients without the epsilon 4 allele and possibly nondiabetic subjects with the epsilon 4 allele, although the underlying mechanism is unknown.


Asunto(s)
Alelos , Apolipoproteínas E/sangre , Diabetes Mellitus Tipo 2/sangre , Hipercolesterolemia/sangre , Adulto , Apolipoproteína E4 , Apolipoproteínas E/genética , Colesterol/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/genética , Humanos , Hipercolesterolemia/complicaciones , Hipercolesterolemia/genética , Lipoproteínas/sangre , Persona de Mediana Edad , Fenotipo , Triglicéridos/sangre
4.
Diabetes ; 39(8): 983-8, 1990 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2165005

RESUMEN

Thrombomodulin (TM) is a membrane protein in the vascular endothelium, and it plays an important role as a cofactor in the thrombin-catalyzed activation of protein C. It has also been found in human plasma; however, its clinical significance is not known. In this study, fasting plasma TM concentrations in 67 diabetic patients with different degrees of albuminuria (39 men aged 57 +/- 8 yr, 28 women aged 57 +/- 11 yr; means +/- SD) and 34 age- and sex-matched healthy subjects were investigated by use of a one-step sandwich enzyme immunoassay, a new method developed by H.I. and others. As a screening, the patients were divided into three groups according to the first morning urinary concentrations of albumin: group 1, less than 30 micrograms/ml (normoalbuminuria); group 2, 30-140 micrograms/ml (microalbuminuria); group 3, greater than 140 micrograms/ml (clinical nephropathy). There was no significant difference in plasma TM level between the control group (17.7 +/- 3.7 ng/ml, n = 34) and group 1 (16.9 +/- 3.4 ng/ml, n = 30); however, plasma TM concentrations in group 2 (22.8 +/- 3.4 ng/ml, n = 22) and group 3 (29.6 +/- 6.1 ng/ml, n = 15) increased significantly compared with those in the control group and group 1, respectively. As a further investigation, three timed overnight urine collections were made. The patients were allocated to three groups according to their rates of albumin excretion: group I, less than 20 micrograms/min (normoalbuminuria); group II, 20-200 micrograms/min (microalbuminuria); group III greater than 200 micrograms/min (clinical nephropathy).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Diabetes Mellitus/sangre , Angiopatías Diabéticas/sangre , Neuropatías Diabéticas/sangre , Receptores de Superficie Celular/sangre , Adulto , Anciano , Albuminuria/sangre , Albuminuria/patología , Membrana Celular/fisiología , Membrana Celular/ultraestructura , Permeabilidad de la Membrana Celular/fisiología , Creatina/sangre , Diabetes Mellitus/patología , Angiopatías Diabéticas/patología , Neuropatías Diabéticas/patología , Endotelio Vascular/patología , Endotelio Vascular/ultraestructura , Femenino , Humanos , Masculino , Persona de Mediana Edad , Receptores de Trombina
5.
Diabetes ; 42(7): 948-55, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7685720

RESUMEN

Recent studies have shown that two different voltage-dependent Ca2+ channels are expressed in pancreatic islets, the beta-cell/neuroendocrine-brain and the cardiac subtypes. The effects of chronic hyperglycemia on the levels in pancreatic islets of the mRNAs encoding the alpha 1-subunits of the beta-cell and cardiac subtype Ca2+ channels were studied in rats made hyperglycemic by infusion of glucose for 48 h. A competitive reverse transcriptase-polymerase chain reaction procedure was used to obtain quantitative data on the levels of these two transcripts in islets obtained from individual rats. The quantitative polymerase chain reaction data indicate that the levels of mRNA encoding the alpha 1-subunit of the beta-cell Ca2+ channel are 2.5-fold greater than those for the cardiac subtype. The levels of beta-cell Ca2+ channel mRNA were 72.9% lower in the glucose-infused animals when compared with the saline-infused animals (P < 0.005) and those of the cardiac channel were 72.1% lower in the animals infused with glucose (P < 0.02). In contrast, glucose infusion resulted in a twofold increase in insulin mRNA levels and did not significantly alter levels of beta-actin mRNA. In situ hybridization studies revealed that the mRNAs for these two Ca2+ channels are expressed at higher levels in normal rat islets than in the surrounding acinar tissue, which suggests that the observed changes in mRNA levels occur within cells of the pancreatic islet. To assess the possible functional consequences of this reduction in expression of mRNA for the Ca2+ channels, the insulin secretory responses of perfused pancreases to the Ca2+ channel agonist Bay K8644 were studied.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Canales de Calcio/genética , Glucosa/farmacología , Islotes Pancreáticos/metabolismo , ARN Mensajero/metabolismo , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Actinas/biosíntesis , Actinas/genética , Animales , Elementos sin Sentido (Genética) , Secuencia de Bases , Canales de Calcio/efectos de los fármacos , ADN , Expresión Génica/efectos de los fármacos , Técnicas In Vitro , Insulina/metabolismo , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Masculino , Datos de Secuencia Molecular , Miocardio/metabolismo , Oligodesoxirribonucleótidos , Perfusión , Reacción en Cadena de la Polimerasa , Ratas , Ratas Wistar , Transfección
6.
Endocrinology ; 135(3): 1010-7, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8070343

RESUMEN

Expression of the genes for voltage-dependent calcium channels (VDCCs), glucose transporter-2 (GLUT2), and glucokinase was studied in pancreatic islets obtained from normal rats after periods of fasting and refeeding using a competitive polymerase chain reaction procedure. A 72-h fast induced about a 3-fold decrease in the beta-cell/neuroendocrine type VDCC alpha 1-subunit and GLUT2 messenger RNA (mRNA) levels and about a 2-fold decrease in insulin and glucokinase mRNA levels compared to those in fed and refed rats. No significant differences were found in beta-actin and the cardiac-type VDCC alpha 1-subunit mRNA levels among fed, fasted, anf refed rats. We also studied insulin secretion from the isolated perfused pancreata obtained from these animals. We found an elevated threshold and decreased insulin release in response to a stepwise increase in glucose concentrations in the isolated perfused pancreata obtained from fasted rats. Fasting also resulted in a dramatic decrease in insulin secretory responses during the application of an L-type VDCC agonist, Bay K8644 (1 microM). Furthermore, fasting resulted in a significant decrease in both 45Ca2+ uptake by the isolated islets and insulin release from the islets. A strong positive correlation was observed between glucose-induced 45Ca2+ uptake and insulin output among the animals studied. On the other hand, after a 24-h refeeding, significant increases in the insulin secretory response to glucose and Bay K8644 were found, with a normalization in mRNA levels for these components. It, thus, appears that the alterations in beta-cell sensitivity to glucose that occur with fasting and refeeding are the result of complex metabolic alterations in the islet associated with reductions in expression of at least in part the beta-cell/neuroendocrine type VDCC in addition to two components of the glucose-sensing apparatus, including glucokinase and GLUT2, and the reduction in mRNA for insulin.


Asunto(s)
Canales de Calcio/genética , Ayuno , Glucoquinasa/genética , Insulina/metabolismo , Proteínas de Transporte de Monosacáridos/genética , ARN Mensajero/metabolismo , Animales , Secuencia de Bases , Calcio/metabolismo , Alimentos , Transportador de Glucosa de Tipo 2 , Técnicas In Vitro , Secreción de Insulina , Islotes Pancreáticos/metabolismo , Masculino , Sondas Moleculares/genética , Datos de Secuencia Molecular , Ratas , Ratas Wistar
7.
Atherosclerosis ; 84(1): 49-53, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2248620

RESUMEN

It has been reported that total cholesterol (Chol) response to probucol is greater in familial hypercholesterolemic (FH) patients with apo E4 than in those without apo E4. We further examined the effect of probucol on plasma triglyceride (TG) and lipoprotein-Chol levels as well as total Chol levels in heterozygous FH patients with apo E4 (n = 14 for apo E4/3, n = 1 for apo E4/4) and without apo E4 (n = 31 for apo E3/3). Probucol was administered in a dosage of 500 mg twice daily for 3 months. The reduction in total Chol levels was significantly greater in FH patients with apo E4 (-90 mg/dl, -27.5%) than in those without apo E4 (-41 mg/dl, -13.7%). The reduction in low density lipoprotein (LDL)-Chol levels was also significantly greater in FH patients with apo E4 (-73 mg/dl vs. -34 mg/dl). There was a significant difference in the change in TG and very low density lipoprotein (VLDL)-Chol levels with treatment between the FH patients with apo E4 (-37 and -8 mg/dl, respectively) and without apo E4 (+8 and +2 mg/dl, respectively). However, there was no significant difference in the reduction in HDL-Chol levels between the 2 groups (-9 mg/dl vs. -9 mg/dl). It is concluded that FH patients with apo E4 showed the greater reduction in plasma TG levels as well as total Chol levels with probucol treatment than those without apo E4, and that the greater reduction in total Chol levels in them, as reported previously, was mainly due to the greater reduction in LDL-Chol levels and slightly due to that in VLDL-Chol levels.


Asunto(s)
Apolipoproteínas E/sangre , Hiperlipoproteinemia Tipo II/sangre , Lípidos/sangre , Lipoproteínas/sangre , Probucol/farmacología , Apolipoproteína E4 , Femenino , Humanos , Masculino , Persona de Mediana Edad
8.
J Hypertens ; 17(9): 1257-63, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10489102

RESUMEN

OBJECTIVE: To study whether abnormalities of autonomic function exist in patients with essential hypertension and neurovascular compression (NVC) of the medulla oblongata. SUBJECTS AND METHODS: We studied 25 untreated patients with essential hypertension (13 men and 12 women, 27-74 years old). High-resolution magnetic resonance imaging and magnetic resonance angiography were used to detect NVC. Twenty-four-hour ambulatory monitoring of blood pressure and electrocardiogram were performed, and the power spectrum of heart rate variability was analyzed. On a separate day, various autonomic activity tests, including mental stress, hand grip, cold pressor, and Valsalva maneuver were performed. Baroreflex sensitivity was calculated from changes of blood pressure and R-R interval during phenylephrine infusion. A clonidine suppression test was also performed, with measurement of plasma catecholamine levels. RESULTS: Fourteen of 25 patients (56%) had NVC (C group), and 11 patients did not have NVC (NC group). There were no significant differences in age, sex, family history, or duration of hypertension between the C and NC groups. Average 24-h systolic blood pressure was similar between the two groups, although 24-h diastolic blood pressure was higher in the C group than the NC group. Daytime, night-time, and 24-h heart rate was significantly higher in the C group than in the NC group. Night-time low frequency/high frequency ratio was slightly higher in the C group. Plasma norepinephrine levels were significantly higher (467 +/- 217 versus 299 +/- 122 pg/ml), and baroflex sensitivity was slightly lower in the C group than in the NC group. Responses of blood pressure and heart rate to mental stress, cold pressor, hand grip, Valsalva maneuver, phenylephrine infusion, and clonidine tests were not significantly different between the two groups. CONCLUSIONS: NVC of the medulla oblongata was frequently found in patients with essential hypertension. Patients with NVC appeared to have enhanced sympathetic nervous activity compared with those without the compression.


Asunto(s)
Sistema Nervioso Autónomo/fisiología , Hipertensión/patología , Hipertensión/fisiopatología , Bulbo Raquídeo/patología , Síndromes de Compresión Nerviosa/fisiopatología , Adulto , Anciano , Barorreflejo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Ritmo Circadiano , Clonidina/farmacología , Femenino , Humanos , Hipertensión/sangre , Hipertensión/diagnóstico , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Síndromes de Compresión Nerviosa/sangre , Síndromes de Compresión Nerviosa/diagnóstico , Norepinefrina/sangre , Fenilefrina/farmacología
9.
Hypertens Res ; 24(4): 463-7, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11510761

RESUMEN

Many genes and environmental factors are involved in the pathogenesis of hypertension, but the exact cause of essential hypertension has not yet been clarified. Gene polymorphism of the renin-angiotensin system (RAS) is one of the candidates. In the current study, we examined whether there was a correlation between the gene polymorphisms in RAS and either the choice of antihypertensive drugs or their efficacy. Subjects with essential hypertension (n=299) were recruited from among the outpatients of Osaka University Hospital and provided their informed consent for genetic analysis. Physicians freely chose the antihypertensive drugs and adjusted its dose until the patient's blood pressure was well controlled. The efficacy of each antihypertensive drug was estimated using the following formula: ABP=BP 1 (before treatment) - BP 2 (after treatment)/BP 1 x 100 (%). Gene variants in RAS were determined using PCR or PCR-RFLP (restriction fragment of polymorphism). The gene polymorphisms of RAS were not associated with delta SBP or ADBP. However, the mean ASBP in subjects with a deletion homozygote of the angiotensin converting enzyme gene (ACE/DD) was significantly lower (p<0.05) than that in patients with an insertion I allele of the ACE gene. The gene polymorphisms of RAS did not significantly affect the choice of antihypertensive drugs. Even though gene polymorphism in the renin angiotensin system was not a major factor in the antihypertensive therapy, the determination of genotype might be of help in the management of essential hypertension.


Asunto(s)
Antihipertensivos/uso terapéutico , Variación Genética , Hipertensión/tratamiento farmacológico , Hipertensión/genética , Sistema Renina-Angiotensina/genética , Presión Sanguínea/efectos de los fármacos , Femenino , Genotipo , Humanos , Hipertensión/fisiopatología , Masculino , Polimorfismo Genético , Resultado del Tratamiento
10.
Hypertens Res ; 24(3): 295-8, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11409653

RESUMEN

Predisposition to essential hypertension is associated with gene polymorphisms of the renin angiotensin system (RAS). Gene polymorphisms of the angiotensinogen and angiotensin converting enzyme genes are known to be risk factors for hypertension, while few studies concerning the renin gene polymorphism have been published. In the present investigation, we carried out a case control study using a Japanese population to examine the genetic influence of the renin gene on the predisposition to hypertension. Patients (n=235) recruited from outpatients at Osaka University Hospital and diagnosed with essential hypertension or receiving long-term antihypertensive medication participated in the study. Normotensive control subjects (n=510) without a history of hypertension and without diabetes mellitus were recruited from the same population, and were sex-matched with experimental subjects. A polymorphism in intron 9 of the human renin gene was determined as the Mbo I restriction fragment length polymorphism (Mbo I-RFLP). There was no significant association between Mbo I-RFLP of the renin gene and predisposition to essential hypertension in Japanese (p>0.05, chi2=2.1). These results suggest that the Mbo I (+) allele of the renin gene does not increase the risk for hypertension in Japanese.


Asunto(s)
Hipertensión/genética , Polimorfismo de Longitud del Fragmento de Restricción , Renina/genética , Anciano , Estudios de Casos y Controles , Desoxirribonucleasas de Localización Especificada Tipo II , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Japón , Masculino , Persona de Mediana Edad
11.
Diabetes Res Clin Pract ; 8(3): 201-14, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1971211

RESUMEN

We investigated the pathological changes in pancreatic islets during the development of diabetes in spontaneously diabetic Chinese hamsters of the Asahikawa colony (CHAD), using morphometric analysis and specific immunocytochemical methods. We also investigated the relationships between changes in islet cell composition and the hormonal changes in the plasma and pancreas. Plasma and pancreatic insulin levels were significantly lower in diabetic hamsters than in pre-diabetic hamsters. However, plasma insulin levels in the pre-diabetic hamsters were significantly higher than those in the hamsters from the non-diabetic control strain, although the pancreatic insulin content in the pre-diabetics was significantly lower than that in the non-diabetics. Since even a severely diabetic CHAD is alive for many months after the onset of the disease without injections of insulin, its clinical course seems to be close to that of type 2 human diabetes. In contrast, plasma and pancreatic glucagon levels were significantly higher in diabetic hamsters than in non-diabetics and pre-diabetics. There were significantly positive correlations between plasma and pancreatic insulin, and plasma and pancreatic glucagon levels in CHAD (P less than 0.01). On the other hand, no significant differences in the pancreatic somatostatin content were found among the non-diabetics, pre-diabetics, and severe diabetics. Significant correlations were found between plasma and pancreatic hormone levels (except for somatostatin) and the advance of diabetes in CHAD (P less than 0.01). Morphometric analysis by planimeter revealed that islets in the severe diabetics were 25% smaller than in the pre-diabetics. Significantly less B-cell area within the diabetic islets was found when compared with the non-diabetic and pre-diabetic islets. Significantly larger A- and D-cell areas within the diabetic islets were found compared with the non-diabetic and pre-diabetic islets. There was a significant correlation between the areas of the three types of cell within the islets and the severity of diabetes (P less than 0.01). It is suggested, therefore, that the pancreatic islet function in CHAD is closely associated with the morphologic changes in islet endocrine cells. The elevation of plasma and pancreatic glucagon levels and the marked increase of the A-cell area within the islets from severely diabetic CHAD may reveal an absolute increase of A-cell numbers.


Asunto(s)
Diabetes Mellitus Experimental/patología , Islotes Pancreáticos/patología , Páncreas/patología , Animales , Cricetinae , Cricetulus , Diabetes Mellitus Experimental/sangre , Femenino , Glucagón/análisis , Glucagón/sangre , Técnicas para Inmunoenzimas , Insulina/análisis , Insulina/sangre , Masculino , Somatostatina/análisis
12.
Diabetes Res Clin Pract ; 1(5): 273-80, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3915266

RESUMEN

Dynamic insulin and glucagon response to glucose was examined in the perifusion system to investigate the relationship between pancreatic hormone content and the pattern of hormone secretion in diabetic Chinese hamsters of the Asahikawa colony (CHA). Isolated islets of normals and diabetics from the CHA were perifused. When the medium was changed to high glucose (500 mg/dl), a low insulin response and paradoxical glucagon response were seen in diabetics compared with normals. Positive correlations were found between pancreatic insulin and the amount of perifusate insulin, and glucagon content and glucagon release, respectively. It is suggested, accordingly, that pancreatic hormone content is related to the amount of hormone release in CHA. A negative correlation between the amount of perifusate insulin and glucagon release was found. It is suggested, therefore, that an impaired suppression of glucagon release in the diabetic CHA animals could be attributed at least to insulin deficiency. These findings agree with the histological discovery of decreased B-cells and increased A-cells in the diabetic islets. Both decreased B-cells and islet numbers could be the cause of the low insulin response to glucose. Increased numbers of A-cells with hyperfunction resulting from local insulin deficiency could be the cause of the paradoxical glucagon response.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Glucagón/metabolismo , Glucosa/farmacología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Animales , Cricetinae , Cricetulus , Femenino , Técnicas In Vitro , Secreción de Insulina , Masculino
13.
Diabetes Res Clin Pract ; 1(2): 87-94, 1985 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2873008

RESUMEN

The relationship between pancreatic hormone content and pattern of hormone release has not been completely elucidated because of heterogeneity in diabetes. Accordingly, this study was performed to establish the relationship, using spontaneously diabetic Chinese hamsters in the Asahikawa colony, a newly discovered experimental model resembling insulin-deficient diabetes in humans. As a result of investigations of insulin and glucagon responses to glucose or arginine in vivo and in vitro using isolated islets obtained by the collagenase procedure, a decreased insulin response and paradoxical glucagon response to glucose, and an excessive glucagon response to arginine were found in the diabetic animals. While the yield of isolated islets tended to decrease, a decreased pancreatic insulin content and increased pancreatic glucagon content were found as the diabetic state advanced. It may be suggested, therefore, that the relationship between pancreatic hormone content and pattern of hormone release in diabetic animals in the Asahikawa colony is based on the disruption of islets, disruption or dysfunction of B-cells and hyperplasia or hypertrophy of A-cells by some cause genetically determined.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Glucagón/metabolismo , Insulina/metabolismo , Animales , Arginina/farmacología , Glucemia/metabolismo , Cricetinae , Cricetulus , Relación Dosis-Respuesta a Droga , Femenino , Glucagón/sangre , Glucosa/farmacología , Prueba de Tolerancia a la Glucosa , Insulina/sangre , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Masculino , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Somatostatina/farmacología
14.
Diabetes Res Clin Pract ; 3(3): 143-51, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3297590

RESUMEN

The influence of xenogeneic islet cell surface antibodies (ICSA) on the hormonal secretion of non-B islet cells has not been completely elucidated. Accordingly, we investigated the influence of xenogeneic antiserum on glucagon release from A cells, as representative of non-B islet cells, together with other characteristics of the antiserum. Anti-islet cell sera were produced in rabbits by xenogeneic immunization with dispersed hamster islet cells. Rabbit anti-hamster islet cell surface antibodies were detected both qualitatively by indirect immunofluorescence analyses and quantitatively by 125I-protein A radioligand assay. However, antiserum did not induce cell surface immunofluorescence on rat or mouse islet cells. As a result of evaluation of the specific cytotoxicity using 51Cr release assay, antiserum was observed to induce a significantly higher release of 51Cr compared with that of normal rabbit serum in complement-dependent antibody-mediated cytotoxicity. Both glucose-stimulated insulin and arginine-stimulated glucagon release were suppressed by xenogeneic antiserum not only in the presence but also in the absence of complement. It is concluded, therefore, that xenogeneic antiserum has a relative species specificity and non-selectively binds to islet cells in contrast with the non-species specificity and preferential binding to pancreatic B cells of human ICSA, although heterogeneity in ICSA-positive sera has been suggested.


Asunto(s)
Autoanticuerpos , Glucagón/metabolismo , Insulina/metabolismo , Islotes Pancreáticos/inmunología , Animales , Citotoxicidad Celular Dependiente de Anticuerpos , Proteínas del Sistema Complemento/inmunología , Cricetinae , Femenino , Técnica del Anticuerpo Fluorescente , Mesocricetus , Conejos , Proteína Estafilocócica A/metabolismo , Azul de Tripano/metabolismo
15.
Diabetes Res Clin Pract ; 3(6): 297-305, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3665731

RESUMEN

We studied the effect of spontaneous long-term (9-10 months) diabetes on the heart of Chinese hamsters (CHAD strain) to elucidate the relationship between diabetes mellitus and cardiomyopathy. The diabetic hamsters, aged approximately 11 months, showed body weight loss, hyperglycemia (mean fasting plasma glucose 402 mg/dl), hypoinsulinemia, hyperlipidemia and ketonemia. The diabetic hamsters showed reduced activities of cytoplasmic glycolytic key enzymes; hexokinase, pyruvate kinase and phosphofructokinase, increases in cardiac glycogen and glucose-6-phosphate contents and a 40% decrease in cardiac ATP content, indicating decreased energy production. An accumulation of myocardial triglyceride and cholesterol was found in the diabetic hamsters. In addition, the cardiac norepinephrine content was increased in the diabetic hamsters, suggesting the presence of autonomic nervous disorder. Increased heart weight and thickening of the septum and both ventricular walls were found in the diabetic hamsters. Light-microscopic analysis revealed that 42.9% of the diabetic hamsters had myocardial degeneration without any vascular lesion of extramural large and intramural small vessels, whereas the non-diabetic controls had no myocardial or vascular lesions. These data suggest that the diabetic Chinese hamsters had cardiomyopathy, which is possibly caused by extravascular factors such as metabolic or autonomic nervous disorder although conclusive evidence is lacking.


Asunto(s)
Cardiomiopatías/patología , Diabetes Mellitus/patología , Animales , Cardiomiopatías/enzimología , Cardiomiopatías/metabolismo , Cricetinae , Cricetulus , Diabetes Mellitus/enzimología , Diabetes Mellitus/metabolismo , Femenino , Masculino , Miocardio/enzimología , Miocardio/metabolismo , Especificidad de la Especie
16.
Diabetes Res Clin Pract ; 50(3): 195-202, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11106834

RESUMEN

We investigated the relationship between advanced diabetic retinopathy (ADR) and an angiotensin-converting enzyme (ACE) gene polymorphism in subjects with type 2 diabetes and ADR, pre-proliferative (PrePDR) or proliferative diabetic retinopathy (PDR) without overt nephropathy. Polymerase chain reactions were used to detect insertion/deletion (I/D) polymorphisms of the ACE gene. There was no difference in the frequency of II, ID, or DD genotypes, or of I and D alleles among subjects with type 2 diabetes without diabetic retinopathy (NDR) or with simple diabetic retinopathy (SDR) and non-diabetic controls. There was also no difference in the frequency of ACE genotypes among subjects with type 2 diabetes with NDR, or SDR and ADR. However, the frequency of the ACE DD genotype in ADR was significantly higher than that in controls (chi(2)=6.64, P=0.036). On the other hand, the frequency of the D allele in ADR was significantly higher than that in controls (chi(2)=6.33, P=0.012), NDR (chi(2)=4.18, P=0.041) and SDR (chi(2)=4. 89, P=0.027), respectively. These results indicate a significant relationship between the presence of the D allele polymorphism in the ACE gene and ADR in Japanese subjects with type 2 diabetes and no overt nephropathy.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Retinopatía Diabética/genética , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Eliminación de Secuencia , Albuminuria , Presión Sanguínea , Elementos Transponibles de ADN , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/fisiopatología , Retinopatía Diabética/enzimología , Retinopatía Diabética/fisiopatología , Progresión de la Enfermedad , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Peptidil-Dipeptidasa A/metabolismo , Reacción en Cadena de la Polimerasa , Valores de Referencia
18.
J Hum Hypertens ; 27(7): 417-20, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23254592

RESUMEN

It has been suggested that fibrates, lipid-lowering agents with a peroxisome proliferator-activated receptor-α agonistic property, lower blood pressure (BP) in some experimental models of hypertension. However, the effect of fibrates on BP in humans has been inconsistent, and there are few studies using home or ambulatory BP monitoring. We investigated the effects of bezafibrate on office, home and ambulatory BP in hypertensive patients with dyslipidemia. Thirty-two essential hypertensive patients with dyslipidemia (6 men and 26 women, mean age 65±8 years old) were assigned to a control period and a bezafibrate period (200 mg twice daily) for 8 weeks each in a randomized crossover manner. Bezafibrate significantly reduced serum triglyceride, total and low-density lipoprotein-cholesterol, blood glucose, plasma insulin, the homeostasis model assessment ratio and increased high-density lipoprotein-cholesterol. Compared with the control period, changes in office, home and 24-h BP with bezafibrate were -0.7±2.1/-1.6±1.2 mm Hg, +0.9±1.0/-0.5±0.6 and +0.8±1.4/-0.6±0.9 mm Hg, respectively. None of these differences in BP was significant. In conclusion, bezafibrate improved lipid metabolism and insulin sensitivity but did not affect office, home or ambulatory BP in hypertensive patients with dyslipidemia. Fibrates do not appear to lower BP in patients with essential hypertension.


Asunto(s)
Antihipertensivos/uso terapéutico , Bezafibrato/uso terapéutico , Monitoreo Ambulatorio de la Presión Arterial , Presión Sanguínea/efectos de los fármacos , Dislipidemias/tratamiento farmacológico , Hipertensión/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Visita a Consultorio Médico , Anciano , Biomarcadores/sangre , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Estudios Cruzados , Dislipidemias/sangre , Dislipidemias/complicaciones , Dislipidemias/diagnóstico , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Insulina/sangre , Resistencia a la Insulina , Japón , Lípidos/sangre , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Resultado del Tratamiento
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