Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Hypertension ; 36(1): 68-72, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10904014

RESUMO

In 10- to 12-week-old Dahl salt-sensitive (DS) and salt-resistant (DR) rats fed a 0.3% salt diet (n=10 in each group), flow-pressure and pressure-glomerular filtration rate (F-P and P-GFR, respectively) relationships were established for maximally vasodilated perfused kidneys. From these relationships, 3 indices of vascular structural properties were estimated: slope of F-P (minimal renal vascular resistance reflecting overall luminal dimensions of preglomerular and postglomerular vasculature), slope of P-GFR (glomerular filtration capability against pressure), and threshold pressure for beginning filtration at P-GFR (preglomerular-to-postglomerular vascular resistance ratio). Thereafter, maximal renal vascular resistance was determined to assess wall-to-lumen ratios of the resistance vessels in half of each group. In the remainder, the kidneys were perfusion-fixed for histological analysis. Mean arterial pressure did not differ between the DS and DR rats. There were no significant differences in the slopes of F-P between the 2 groups. In contrast, the slope of P-GFR was significantly lower (33%) in DS rats than in DR rats, although the DS kidneys began filtering at a threshold pressure similar to that of the DR kidneys. Thus, in DS rats, there were no abnormalities in luminal dimensions at preglomerular and postglomerular vascular segments, but the kidney filtration capacity decreased at any given increase in pressure. Maximal vascular resistance was greater in DS than in DR rats, a finding compatible with the histological appearance, which showed vascular hypertrophy with little, if any, vascular narrowing in the interlobular arteries of DS rats. In conclusion, hypertrophic remodeling without vascular narrowing at preglomerular resistance vessels and structural defects in filtering at the glomeruli could occur in prehypertensive DS rats.


Assuntos
Hipertensão/patologia , Rim/irrigação sanguínea , Cloreto de Sódio na Dieta/farmacologia , Animais , Hemodinâmica , Hipertensão/fisiopatologia , Rim/fisiopatologia , Masculino , Ratos , Artéria Renal/patologia , Artéria Renal/fisiopatologia
2.
J Hypertens ; 15(10): 1187-95, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9350594

RESUMO

OBJECTIVES: To study the effects of denervation of the kidney on renal vascular resistance at maximal dilatation and renal function during the development of hypertension in the spontaneously hypertensive rat (SHR). METHODS: SHR aged 6 weeks were subjected to left renal denervation or a sham-operation (n = 18 denervated, n = 13 sham). When they were aged 10 weeks, pairs of denervated and sham-operated left kidneys were perfused with 2% dextran in Tyrode's solution and pressure-flow and pressure-glomerular filtration rate (GFR) relationships at maximal vasodilation were established. The awake mean arterial blood pressure, in-vivo renal function and renal noradrenaline content were also measured. RESULTS: There were no significant differences between the pressure-flow relationships for denervated and sham-operated kidneys. However, there was a marked, parallel, shift leftwards in the pressure-GFR relationship (P < 0.001). Thus, the denervated kidneys commenced filtering at a lower threshold perfusion pressure than did the sham-operated ones. In-vivo renal plasma flow and GFR were significantly greater in the denervated left kidneys of SHR than they were in the contralateral kidneys. The noradrenaline content in denervated kidneys was 5 +/- 3% of that in innervated kidneys. The awake mean arterial pressure was 135 +/- 1 and 138 +/- 2 mmHg in the denervated and sham-operated groups respectively. CONCLUSION: Denervation of the kidney of SHR aged 6 weeks of age altered the pressure-GFR but not the pressure-flow relationship for these rats 4 weeks later. The results are compatible with there having been an increase in average preglomerular and a decrease in post-glomerular vessel lumen diameters. These changes suggest that the renal nerves affect the structural development of the renal vasculature in SHR.


Assuntos
Denervação , Hipertensão/fisiopatologia , Rim/fisiologia , Artéria Renal/inervação , Resistência Vascular/fisiologia , Animais , Pressão Sanguínea , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Taxa de Filtração Glomerular , Hipertensão/etiologia , Hipertensão/terapia , Rim/irrigação sanguínea , Rim/metabolismo , Masculino , Norepinefrina/metabolismo , Ratos , Ratos Endogâmicos SHR , Fluxo Plasmático Renal
3.
Br J Pharmacol ; 119(2): 365-73, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8886422

RESUMO

1. We tested the effects on systemic haemodynamics and renal function, of inhibition of endopeptidase (EP) 24.15 (E.C. 3.4.24.15), in conscious uninephrectomized rabbits in which the activities of angiotensin converting enzyme (ACE, E.C. 3.4.15.1) and neutral endopeptidase (EP 24.11, E.C. 3.4.24.11) were already inhibited. To test the role of bradykinin B2-receptors in mediating the effects following inhibition of these enzymes, the antagonist Hoe 140 was used. 2. Hoe 140 (0.1 mg kg-1, i.v.) did not affect resting mean arterial pressure or heart rate, but antagonized the depressor effect of right atrial administration of bradykinin. The dose-response curve for bradykinin was shifted more than 1000 fold to the right for more than 4 h. Hoe 140 approximately doubled resting urine flow and increased fractional Na+ excretion from 4.2 to 6.0%; consistent with the hypothesis that it exerts a partial agonist effect on the kidney. 3. Combined inhibition of ACE (captopril; 0.25 mg kg-1 plus 0.2 mg kg-1h-1) and EP 24.11 (SCH 39370; 3 mg kg-1 plus 3 mg kg-1h-1) was followed by a sustained reduction in arterial pressure (-6 +/- 2 mmHg) and increase in heart rate (35 +/- 7 beats min-1). There was a small increase in renal blood flow (by 6.5 +/- 3.2% relative to vehicle-treatment) without a change in glomerular filtration rate, and about a 150% increase in Na+ excretion. Hoe 140 (0.1 mg kg-1, i.v.) pretreatment did not influence the renal effects of captopril and SCH 39370, although it did appear to blunt their hypotensive and tachycardic effects. 4. When EP 24.15 was inhibited with N-[1-(R,S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate (cFP-AAY-pAB; 5 mg kg-1 plus 3 mg kg-1h-1, i.v.) in rabbits pretreated with captopril and SCH 39370, no changes in systemic haemodynamics or renal function were observed. 5. We concluded that in conscious uninephrectomized rabbits, EP 24.15 does not play a major role in modulating renal function, at least under conditions where ACE and EP 24.11 are already inhibited. In contrast, ACE and/or EP 24.11 do modulate renal function in this model, but their influences are mediated chiefly through metabolism of peptides other than bradykinin.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores Enzimáticos/farmacologia , Rim/ultraestrutura , Metaloendopeptidases/antagonistas & inibidores , Neprilisina/antagonistas & inibidores , Receptores da Bradicinina/fisiologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Bradicinina/análogos & derivados , Bradicinina/farmacologia , Captopril/farmacologia , Estado de Consciência , Dipeptídeos/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/enzimologia , Metaloendopeptidases/metabolismo , Neprilisina/metabolismo , Oligopeptídeos/farmacologia , Peptidil Dipeptidase A/metabolismo , Inibidores de Proteases/farmacologia , Coelhos
4.
Br J Pharmacol ; 118(5): 1269-77, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8818353

RESUMO

1. The role of the metalloendopeptidase EC 3.4.24.15 (EP 24.15) in peptide metabolism in vivo is unknown, in part reflecting the lack of a stable enzyme inhibitor. The most commonly used inhibitor, N-[1-(R,S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate (cFP-AAY-pAB, Ki = 16 nM), although selective in vitro, is rapidly degraded in the circulation to cFP-Ala-Ala, an angiotensin converting enzyme (ACE) inhibitor. This metabolite is thought to be generated by neutral endopeptidase (NEP; EC 3.4.24.11), as the Ala-Tyr bond of cFP-AAY-pAB is cleaved by NEP in vitro. In the present study, we have examined the role of NEP in the metabolism of cFP-AAY-pAB in vivo, and have tested a series of inhibitor analogues, substituted at the second alanine, for both potency and stability relative to the parent compound. 2. Analogues were screened for inhibition of fluorescent substrate cleavage by recombinant rat testes EP 24.15. D-Ala or Asp substitution abolished inhibitory activity, while Val-, Ser- and Leu-substituted analogues retained activity, albeit at a reduced potency. A relative potency order of Ala (1) > Val (0.3) > Ser (0.16) > Leu (0.06) was observed. Resistance to cleavage by NEP was assessed by incubation of the analogues with rabbit kidney membranes. The parent compound was readily degraded, but the analogues were twice (Ser) and greater than 10 fold (Leu and Val) more resistant to cleavage. 3. Metabolism of cFP-AAY-pAB and the Val-substituted analogue was also examined in conscious rabbits. A bolus injection of cFP-AAY-pAB (5 mg kg-1, i.v.) significantly reduced the blood pressure response to angiotensin I, indicating ACE inhibition. Pretreatment with NEP inhibitors, SCH 39370 or phosphoramidon, slowed the loss of cFP-AAY-pAB from the plasma, but did not prevent inhibition of ACE. Injection of 1 mg kg-1 inhibitor resulted in plasma concentrations at 10 s of 23.5 microM (cFP-AAY-pAB) and 18.0 microM (cFP-AVY-pAB), which fell 100 fold over 5 min. Co-injection of 125I-labelled inhibitor revealed that 80-85% of the radioactivity had disappeared from the circulation within 5 min, and h.p.l.c. analysis demonstrated that only 25-30% of the radiolabel remained as intact inhibitor at this time. Both analogues were cleared from the circulation at the same rate, and both inhibitors blunted the pressor response to angiotensin I, indicative of ACE inhibition. 4. These results suggest that both NEP and other clearance/degradation mechanisms severely limit the usefulness of peptide-based inhibitors such as cFP-AAY-pAB. To examine further EP 24.15 function in vivo, more stable inhibitors, preferably non-peptide, must be developed, for which these peptide-based inhibitors may serve as useful molecular templates.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/metabolismo , Dipeptídeos/farmacologia , Glicopeptídeos/farmacologia , Metaloendopeptidases/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Análise de Variância , Angiotensina II/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Bradicinina/farmacologia , Relação Dose-Resposta a Droga , Hormônio Liberador de Gonadotropina , Técnicas In Vitro , Rim/citologia , Rim/enzimologia , Metaloendopeptidases/sangue , Metaloendopeptidases/metabolismo , Coelhos , Ratos , Estereoisomerismo , Vasoconstritores/farmacologia
5.
Am J Hypertens ; 2(11 Pt 1): 834-9, 1989 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2574044

RESUMO

Thirteen patients with essential hypertension were treated with an alpha 1-adrenoceptor antagonist, terazosin (1 to 4 mg/day) for 12 months. To assess the mechanism of its antihypertensive effect, the hemodynamic and endocrinological responses to terazosin were determined before, 3, and 12 months after the administration of terazosin. Blood pressure significantly decreased within 2 weeks after the start of terazosin and its effect was sustained throughout the 12 month period. Pulse rate did not change except slight increase in the third month. The hemodynamic studies revealed that total peripheral resistance significantly decreased and cardiac output slightly increased, indicating that the antihypertensive effect of terazosin is mainly produced by its vasodilation. Blood volume and plasma volume did not change. Although plasma renin activity remained the same, plasma aldosterone significantly decreased in response to terazosin. Plasma noradrenaline increased in the third month, but returned to the baseline level in the twelfth month. Thus, terazosin monotherapy lowered blood pressure throughout one year without drug tolerance including volume expansion and/or accentuation of renin-angiotensin-aldosterone system or sympathetic function.


Assuntos
Hipertensão/tratamento farmacológico , Prazosina/análogos & derivados , Antagonistas Adrenérgicos alfa/uso terapêutico , Adulto , Idoso , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Prazosina/uso terapêutico , Sistema Renina-Angiotensina/efeitos dos fármacos , Fatores de Tempo
6.
Am J Hypertens ; 3(12 Pt 1): 918-26, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2081013

RESUMO

To examine the efficacy and usefulness of captopril-enhanced renal vein renin (RVR) measurements in detecting the functional significance of renal artery stenosis found in hypertensives, we compared these values in 22 patients with arteriographically documented renovascular hypertension due to unilateral (URVH: 14 patients) or bilateral renal artery stenosis (BRVH: 8 patients) and 12 patients with high renin essential hypertension (EHT). Before captopril administration, RVR ratio was less than 1.5 in 8 patients (36.4%) with renovascular hypertension and all patients (100%) with EHT. Captopril enhanced the lateralization of renal vein renin in renovascular hypertension; the postcaptopril RVR ratio was greater than 2.0 in 18 patients (81.8%) and greater than 1.5 in all the patients (100%). On the other hand, RVR ratio remained unchanged in most patients with EHT. There was no significant difference in the postcaptopril RVR ratios between URVH and BRVH. However, the postcaptopril RVR ratio was higher in atherosclerosis (10 patients) than in fibromuscular dysplasia (11 patients) (P less than .05). Captopril also elucidated contralateral renin suppression as expressed by a contralateral/peripheral renin ratio of less than 1.0, which was associated with a favorable outcome of unilateral surgical intervention. Captopril-stimulated RVR indices were valuable in detecting the functionally significant renal artery stenosis and predicting surgical curability in renovascular hypertension.


Assuntos
Captopril , Hipertensão Renovascular/diagnóstico , Veias Renais , Renina/sangue , 1-Sarcosina-8-Isoleucina Angiotensina II , Adulto , Feminino , Humanos , Hipertensão/sangue , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertensão Renovascular/sangue , Hipertensão Renovascular/complicações , Masculino , Pessoa de Meia-Idade , Obstrução da Artéria Renal/sangue , Obstrução da Artéria Renal/complicações , Obstrução da Artéria Renal/diagnóstico
7.
Am J Hypertens ; 12(11 Pt 1): 1063-70, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10604481

RESUMO

To determine whether platelet response to mental stress is altered in essential hypertension, platelet aggregability and plasma beta-thromboglobulin were determined in 24 patients with essential hypertension (11 patients with World Health Organization (WHO) stage I and 13 patients with stage II) and 14 normotensive controls before and after a 10-min arithmetic stress (serial subtraction of 7 from 1000). In normotensive subjects, arithmetic stress did not affect primary aggregations to 1.0 micromol/L adenosine diphosphate (ADP) and to 2.5 micromol/L 5-hydroxytryptamine (5-HT), ADP threshold for biphasic aggregation and plasma beta-thromboglobulin level. In hypertensive patients with WHO stage I, these parameters were similar to those in normotensives before arithmetic stress, but the arithmetic stress test significantly increased primary aggregation to reagents and beta-thromboglobulin level, and decreased threshold of ADP for biphasic aggregation. In WHO stage II patients, platelet aggregability to reagents and beta-thromboglobulin level were already enhanced as compared with WHO stage I patients and normotensive subjects before arithmetic stress. However, the stress-induced changes in platelet function were less pronounced in WHO stage II patients compared with stage I patients. In conclusion, platelet aggregability and proaggregatory effect of mental stress differed depending on the severity of hypertension in patients with essential hypertension; the transient activation of platelet function during stress with no enhancement under the resting condition in the early phase of hypertension and the continuous activation of platelet function in the advanced phase with hypertensive organ damage.


Assuntos
Plaquetas/fisiologia , Hipertensão/fisiopatologia , Agregação Plaquetária , Estresse Psicológico/fisiopatologia , Difosfato de Adenosina , Adulto , Idoso , Aldosterona/sangue , Sítios de Ligação , Biomarcadores/sangue , Catecolaminas/sangue , Feminino , Humanos , Hipertensão/sangue , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Renina/sangue , Serotonina , Índice de Gravidade de Doença , Estresse Psicológico/sangue , beta-Tromboglobulina/metabolismo
8.
Am J Hypertens ; 12(9 Pt 1): 921-4, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10509551

RESUMO

We investigated whether plasma brain and atrial natriuretic peptide (BNP and ANP, respectively) levels could reflect left ventricular (LV) geometry and function in patients with mild to moderate essential hypertension. A positive correlation was found between LV mass index (LVMI) and plasma ANP levels in 84 untreated, hypertensive patients, but not between LVMI and plasma BNP levels. As compared with other geometric patterns, plasma BNP levels were increased in concentric hypertrophy, in which LVMI was increased and LV diastolic function was decreased. These data suggest that production of BNP was increased in hypertensive patients with concentric hypertrophy via LV overload or depression of diastolic function.


Assuntos
Fator Natriurético Atrial/sangue , Ventrículos do Coração/diagnóstico por imagem , Hipertensão/sangue , Peptídeo Natriurético Encefálico/sangue , Remodelação Ventricular , Adulto , Idoso , Biomarcadores/sangue , Ecocardiografia , Epinefrina/sangue , Feminino , Humanos , Hipertensão/diagnóstico por imagem , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/sangue , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Radioimunoensaio , Renina/sangue
9.
Am J Clin Pathol ; 94(2): 217-21, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2371975

RESUMO

A 62-year-old woman was admitted for evaluation of muscular weakness, skin pigmentation, dry mouth, and interstitial pneumonia. During the course of her stay, adult respiratory distress syndrome, hemolytic anemia, renal failure, neurologic dysfunction, and thrombocytopenia appeared. A clinical diagnosis of thrombotic thrombocytopenic purpura (TTP) accompanied by polymyositis and Sjögren's syndrome was made. She died two weeks after the beginning of plasmapheresis, and an autopsy was performed. Immunohistochemistry disclosed deposits of IgM, fibrinogen, and C1q in glomeruli and arterioles and deposits of C3 in small arteries. von Willebrand's factor antigen, which promotes the adhesion of platelets to the subendothelium, was positive in onion-peeled arteries of the kidney and the spleen. These results suggest that immune complexes may have triggered a sequence of events from vascular endothelial injury to TTP.


Assuntos
Doenças Musculares/patologia , Púrpura Trombocitopênica Trombótica/patologia , Síndrome de Sjogren/patologia , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Doenças Musculares/complicações , Doenças Musculares/metabolismo , Púrpura Trombocitopênica Trombótica/complicações , Púrpura Trombocitopênica Trombótica/metabolismo , Síndrome de Sjogren/complicações , Síndrome de Sjogren/metabolismo
10.
Arch Surg ; 128(9): 1065-9, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8396388

RESUMO

PURPOSE: Although autotransfusion is used in a wide variety of surgical procedures, it is largely unexplored for use in oncologic operations. This study evaluates the impact of autotransfusion in hepatectomy for hepatocellular carcinoma. PATIENTS AND METHODS: Fifty-four patients with hepatocellular carcinoma underwent hepatectomy by receiving autologous blood transfusion (group 1). Fifty patients receiving homologous blood without any autologous blood were matched for comparison (group 2). RESULTS: No statistical differences were found between group 1 and group 2 patients in cumulative recurrence rates (62.8% vs 67.3%, respectively) or cumulative survival rates (61.9% vs 52.8%). Autologous transfusion reduced the mean volume of homologous blood used (814 mL vs 3466 mL). The mean postoperative hemoglobin level, platelet count, prothrombin time, and partial thromboplastin time were comparable between groups. CONCLUSIONS: Autotransfusion is a safe and effective procedure in patients with hepatocellular carcinoma undergoing hepatectomy.


Assuntos
Transfusão de Sangue Autóloga , Carcinoma Hepatocelular/cirurgia , Hepatectomia , Neoplasias Hepáticas/cirurgia , Idoso , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Feminino , Seguimentos , Hemoglobinas/análise , Humanos , Cuidados Intraoperatórios , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Contagem de Plaquetas , Complicações Pós-Operatórias , Cuidados Pré-Operatórios , Estudos Prospectivos , Tempo de Protrombina , Recidiva , Taxa de Sobrevida , Resultado do Tratamento
11.
Hypertens Res ; 21(4): 259-66, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9877519

RESUMO

To assess whether we could predict left ventricular (LV) geometric patterns on echocardiography from voltages in standard electrocardiograms (ECG) in patients with essential hypertension, standard 12-lead ECG and echocardiograms were recorded in 106 consecutive, untreated patients (50+/-11 yr old) with essential hypertension. Subjects were assigned to the following four groups based on relative wall thickness (RWT) and LV mass index (LVMI) as determined by echocardiography: a normal geometry group (n = 44), a concentric remodeling group (increased RWT and normal LVMI, n = 10), an eccentric hypertrophy group (increased LVMI and normal RWT, n = 23), and a concentric hypertrophy group (increased RWT and LVMI, n = 29). The following ECG variables were determined: Sokolow-Lyon voltage (SV1 = RV5: SL), Cornell voltage (RaVL + SV3: CN), sum of 12-lead QRS voltage (12-lead sum), and RV6/RV5 ratio (RV6/V5). LVMI correlated with SL, CN, and 12-lead sum, but not with RV6/V5 in the study group as a whole. The concentric hypertrophy group showed increased voltages for all ECG variables except RV6/V5. The concentric remodeling group showed increased voltages for SL and 12-lead sum, but a decreased RV6/V5 ratio. In contrast, the eccentric hypertrophy group had increased voltage only for the 12-lead sum. The combination of SL, RV6/V5, and CN showed modest sensitivity and specificity in the diagnosis of concentric remodeling, concentric hypertrophy, and normal geometry, but not in the diagnosis of eccentric hypertrophy. Conventional ECG criteria can predict LVMI, but not LV geometry in the patients with essential hypertension. The combination of SL, CN, and RV6/V5 is useful in differentiating the four LV geometric patterns seen in essential hypertension.


Assuntos
Ecocardiografia , Eletrocardiografia/métodos , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/etiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
12.
J Pharmacol Toxicol Methods ; 38(1): 33-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9339414

RESUMO

To test the validity of transit-time ultrasound flowmetry for chronic measurement of renal blood flow in dogs, we compared this method with the renal clearance of para-aminohippuric acid (CPAH) (corrected for hematocrit), and with direct volumetric measurements. When flow-probes were implanted without silastic sheeting to stabilize the implant, there was significant disparity between the (within-dog) mean levels of renal blood flow estimated by flow-probe and CPAH. In contrast, when the flow-probe implants were stabilized with silicone sheeting, there was close agreement in each dog between the flow rates measured by the two methods. When flow-probes were calibrated volumetrically in situ, there was a close linear relationship between flow derived from the flow-probe and that measured volumetrically (r = 0.98 +/- 0.02). We conclude that valid, chronic measurement of renal blood flow in dogs can be achieved using transit-time ultrasound flowmetry, provided the implant is stabilized with silicone sheeting.


Assuntos
Rim/irrigação sanguínea , Circulação Renal/fisiologia , Ultrassonografia/métodos , Animais , Velocidade do Fluxo Sanguíneo , Cães , Testes de Função Renal/métodos , Masculino , Próteses e Implantes , Reprodutibilidade dos Testes , Reologia/métodos , Elastômeros de Silicone , Ácido p-Aminoipúrico/farmacocinética
13.
J Hum Hypertens ; 4(1): 13-8, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1971654

RESUMO

To assess the reversibility of left ventricular hypertrophy (LVH) during terazosin therapy, we studied changes in LVH as determined by echocardiography and humoral parameters before and after three and 12 months of terazosin monotherapy in ten patients. Blood pressure decreased within four weeks of treatment and the antihypertensive effect was sustained throughout 12 months. Left ventricular mass index decreased significantly from 126 +/- 22 g/m2 to 109 +/- 24 g/m2 and 98 +/- 23 g/m2 after 3 and 12 months respectively. Interventricular septum (11.2 to 9.8 and 9.0 mm) and posterior wall thickness (10.4 to 9.6 and 8.8 mm) also decreased significantly, whereas left ventricular internal dimensions were unchanged. Total peripheral resistance decreased significantly after initiation of treatment, but cardiac output did not change. Plasma volume, plasma renin activity and plasma noradrenaltine levels were unchanged by terazosin. Thus, terazosin monotherapy reversed LVH associated with decreased peripheral resistance. It is suggested that the reversal of LVH by terazosin is mainly due to the reduction in ventricular afterload and that humoral factors are not involved in its mechanism.


Assuntos
Antagonistas Adrenérgicos alfa/uso terapêutico , Cardiomegalia/tratamento farmacológico , Hipertensão/tratamento farmacológico , Prazosina/análogos & derivados , Idoso , Avaliação de Medicamentos , Eletrocardiografia , Feminino , Ventrículos do Coração/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Volume Plasmático , Prazosina/uso terapêutico , Renina/sangue
14.
J Hum Hypertens ; 6(1): 71-4, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1583634

RESUMO

To investigate the role of cytosolic free calcium, [Ca2+]i, in secondary hypertension, the levels in platelets from 14 secondary hypertensives (7 renovascular hypertension, 7 primary aldosteronism) were compared with those from 21 essential hypertensives and 15 normotensives by means of the fluorescent indicator, quin-2. The mean BP was significantly higher in both the secondary hypertensives and essential hypertensives (122 +/- 8 and 124 +/- 12 mmHg) than in the normotensives (89 +/- 10 mmHg). Cytosolic free calcium in platelets was significantly higher in the essential hypertensives, but not in the secondary hypertensives, compared with the normotensives (182 +/- 34, 141 +/- 17, 138 +/- 15 nM respectively). There was no significant difference in platelet [Ca2+]i between renovascular hypertension and aldosteronism (142 +/- 19 versus 139 +/- 16 nM). There was no correlation between platelet [Ca2+]i and plasma renin activity, plasma aldosterone concentration or plasma noradrenaline concentration in the three groups. Thus, the increase in platelet [Ca2+]i seen in essential hypertension was not found in patients with secondary hypertension. Our results suggest that the cytosolic calcium handling of secondary hypertensive patients with renal artery stenosis or primary aldosteronism differs from that of essential hypertensives.


Assuntos
Plaquetas/química , Cálcio/sangue , Citosol/química , Hiperaldosteronismo/sangue , Hipertensão Renovascular/sangue , Adulto , Idoso , Aldosterona/sangue , Aminoquinolinas , Plaquetas/ultraestrutura , Citosol/ultraestrutura , Feminino , Fluorescência , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Renina/sangue
15.
J Hum Hypertens ; 9(9): 735-9, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8551487

RESUMO

The objective of this study was to assess the regression of vascular structural changes seen in essential hypertension after long-term monotherapy with a calcium antagonist and to clarify the relations to cytosolic free calcium and neurohumoral factors. Blood pressure, minimal vascular resistance (MVR) by strain-gauge plethysmography, cytosolic free calcium in platelets ([Ca2+]i) by Quin 2 method, plasma renin activity (PRA) and plasma aldosterone concentration (PAC), plasma noradrenaline (PNA) and parathyroid hormone (PTH) were measured in 14 essential hypertensives during a placebo period and 2 and 6 months after anti-hypertensive treatment with nilvadipine. Blood pressure decreased from 174 +/- 10/104 +/- 8 mm Hg during the placebo period to 154 +/- 13/93 +/- 14 mm Hg 2 weeks after nilvadipine, and the hypotensive effects were found throughout the 6-month period. Although increased MVR seen in hypertensives did not change after 2 months (from 2.1 +/- 0.7 to 1.9 +/- 0.6 mm Hg/ml/min per 100 ml tissue (PRU), NS), MVR decreased significantly at 6 months (1.6 +/- 0.4, PRU, P < 0.05). Elevated [Ca2+]i seen in hypertensives during the placebo period decreased significantly 2 months after nilvadipine treatment (156 +/- 26 and 140 +/- 27 nM, P < 0.01). The changes in MVR were associated with those in [Ca2+]i 6 months after nilvadipine (r = 0.56, P < 0.05). However, the changes in MVR did not correlate with those in PRA, PAC, PNA or PTH.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Cálcio/metabolismo , Hipertensão/tratamento farmacológico , Nifedipino/análogos & derivados , Resistência Vascular/efeitos dos fármacos , Adulto , Idoso , Análise de Variância , Bloqueadores dos Canais de Cálcio/farmacologia , Citosol/efeitos dos fármacos , Citosol/metabolismo , Feminino , Humanos , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nifedipino/farmacologia , Nifedipino/uso terapêutico , Hormônio Paratireóideo/metabolismo , Pletismografia , Probabilidade , Fatores de Tempo
16.
J Hum Hypertens ; 7(2): 125-30, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8510084

RESUMO

We investigated the effect of one year of enalapril monotherapy on vascular structural changes and calcium metabolism in ten patients with essential hypertension. BP decreased from 169-10/103 +/- 10 mmHg during the placebo period to 138-12/82 +/- 10 mmHg after enalapril therapy. Minimal vascular resistance assessed by the venous occlusion technique with strain-gauge plethysmography was higher in the hypertensive patients than in the normotensive subjects (2.7 +/- 1.2 vs. 1.2 +/- 0.3 mmHg/ml/min per 100 ml tissue, P < 0.01). Although the elevated minimal vascular resistance seen in essential hypertensives decreased to 1.7 +/- 0.5 mmHg/ml/min per 100 ml tissue after enalapril (P < 0.01), it remained higher than that of normotensives (P < 0.05). Cytosolic free calcium ([Ca2+]i) in platelets measured by a Qiun-2 fluorescent indicator was higher in essential hypertensives than in normotensives (189 +/- 38 nM and 138 +/- 14 nM, respectively; P < 0.01). [Ca2+]i of essential hypertensives was reduced to 138 +/- 19 nM after treatment. Plasma renin activity was significantly increased after enalapril. Although plasma ionized calcium concentration did not change, parathyroid hormone was significantly increased after enalapril (from 0.36 +/- 0.22 to 0.58-0.32 ng/ml, P < 0.05). During the placebo period, minimal vascular resistance was correlated with [Ca2+]i (r = 0.62, P < 0.01). There was a close relationship between the changes in minimal vascular resistance and [Ca2+]i (r = 0.78, P < 0.01); however the change in minimal vascular resistance was not associated with changes in BP, catecholamine or parathyroid hormone.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Vasos Sanguíneos/patologia , Cálcio/metabolismo , Enalapril/uso terapêutico , Hipertensão/tratamento farmacológico , Hipertensão/patologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Vasos Sanguíneos/fisiologia , Cálcio/sangue , Feminino , Humanos , Hipertensão/metabolismo , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Fatores de Tempo , Resistência Vascular/efeitos dos fármacos , Resistência Vascular/fisiologia
17.
Hepatol Res ; 17(3): 212-222, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10794975

RESUMO

Background: A hepatic artery-portal vein reciprocal response and hepatic hemodynamics have well been investigated under normal condition, but not under pathologic condition with decreased vascular bed. This study was designed to determine the hemodynamic changes in the hepatic blood flow, tissue perfusion and interrelationship between portal venous flow (PVF) and hepatic arterial flow (HAF) after inflow interruption in the various size of hepatic vascular bed. Methods: Anesthetized dogs were used to measure PVF and HAF using a transit time flow meter and hepatic tissue flow (HTF) using a laser Doppler flow meter before and after portal venous (PVO) or hepatic arterial occlusion (HAO) under various range of portal triad occlusion (PTO). Results: The ratio of HAF/TLF (total liver flow) was 38+/-14% under the basal condition. This ratio did not change under the 30% PTO where there was a similar decrease in PVF and HAF, but reduced to 25+/-12% under the 70% PTO where there was more selective reduction in HAF than PVF. Although a reciprocal HAF increase was observed under any conditions after PVO, the TLF and HTF decreases after PVO were largest under the 70% PTO with the highest PVF/TLF ratio. On the other hand, there was no reciprocal PVF increase in any conditions after HAO, and the TLF and HTF decreases after HAO were minimal under the 70% PTO with the lowest HAF/TLF ratio. Conclusions: With decreasing hepatic vascular bed, dependency of the remnant hepatic hemodynamics and tissue perfusion on the portal blood flow increased. These findings suggest that an integrity of portal venous flow becomes crucial in the remnant hepatic tissue perfusion after extensive hepatic resection.

18.
Am J Med Sci ; 318(6): 413-4, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10616166

RESUMO

A 55-year-old man was admitted to our hospital because of bilateral leg lymphedema. He also showed subcutaneous nodules and CT scan disclosed multiple enlarged lymph nodes at thoracic, abdominal, and inguinal areas. Biopsy of the inguinal lymph node and the subcutaneous nodule revealed noncaseating epithelioid cell granuloma, a finding consistent with sarcoidosis. Lymphedema was attributed to the blockade of lymph flow by the systemic lymph node involvement of the disease. Within 1 week after the initiation of steroid therapy, his leg edema disappeared. Lymphedema could be the initial symptom of systemic sarcoidosis.


Assuntos
Linfedema/etiologia , Sarcoidose/complicações , Sarcoidose/diagnóstico , Diagnóstico Diferencial , Humanos , Perna (Membro) , Linfonodos/patologia , Linfedema/patologia , Masculino , Pessoa de Meia-Idade , Sarcoidose/patologia , Pele/patologia
19.
Arch Pathol Lab Med ; 113(10): 1132-4, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2802942

RESUMO

We describe two long-term hemodialysis patients with hyperaluminumemia, in whom multiple granulomata were found in the livers at autopsy. The granulomata were mainly composed of modified macrophages, and aluminum was constantly detected in the cytoplasm of these macrophages by histochemical analysis, as well as by X-ray microanalysis. These granulomata were also found in the spleen and lymph nodes. The constant presence of aluminum in the mononuclear phagocytic system might have been followed by the development of granulomata. Functional disturbances of the liver were not evident.


Assuntos
Alumínio/sangue , Granuloma/etiologia , Hepatopatias/etiologia , Diálise Renal/efeitos adversos , Adulto , Idoso , Alumínio/análise , Microanálise por Sonda Eletrônica , Feminino , Granuloma/metabolismo , Granuloma/patologia , Humanos , Fígado/análise , Hepatopatias/metabolismo , Hepatopatias/patologia , Masculino
20.
Angiology ; 45(3): 181-6, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8129198

RESUMO

To examine the utility of the single-dose captopril test in detecting renovascular hypertension (RVHT), the authors measured peripheral plasma renin activity (PRA), before and thirty and sixty minutes after an oral dose of captopril (25 mg), in 28 patients with RVHT and 22 patients with high-renin essential hypertension (EHT) without renal artery stenosis who were consuming 8 grams of sodium chloride per day. There was considerable overlap of individual values in basal PRA between the two groups. Sixty minutes after captopril, PRA was higher in RVHT than in EHT patients (74.8 +/- 63.9 versus 15.1 +/- 11.9 ng/mL/hr, P < 0.01). With the cutoff point set at 16 ng/mL/hr, RVHT was detected with a sensitivity of 96% and a specificity of 77%. The discriminating power was also superior to that based on blood pressure response to angiotensin II analogue under sodium depletion, rapid-sequence intravenous pyelography, or renography. These results show that captopril-stimulated peripheral PRA is an adequate screening tool for detecting RVHT in a population with high-renin hypertension.


Assuntos
Captopril , Hipertensão Renovascular/diagnóstico , Hipertensão/diagnóstico , Obstrução da Artéria Renal/complicações , Adulto , Angiografia , Angiotensina II/análogos & derivados , Angiotensina II/antagonistas & inibidores , Pressão Sanguínea/efeitos dos fármacos , Captopril/farmacologia , Diagnóstico Diferencial , Feminino , Humanos , Hipertensão/complicações , Hipertensão Renovascular/etiologia , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Renografia por Radioisótopo , Artéria Renal/diagnóstico por imagem , Obstrução da Artéria Renal/diagnóstico por imagem , Renina/sangue , Sensibilidade e Especificidade , Cloreto de Sódio na Dieta/administração & dosagem , Urografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA