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1.
Acta Paediatr ; 91(1): 51-4, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11883818

RESUMO

UNLABELLED: Deaths following childhood diarrhoea, a major health problem in developing countries, are often associated with malnutrition and septicaemic complications. Folic acid has been used in the treatment of acute and chronic diarrhoea in the tropics. Using a rat model, we evaluated the protective effect of large doses of folic acid on diarrhoea, small intestinal bacterial overgrowth and translocation of enteric bacteria into mesenteric lymph nodes induced by a raw red kidney bean-based diet containing lectin (phytohemagglutinin). Long-Evans rats in 2 groups of 5 each (60 g to 70 g in weight, 28 d old) were used. All 10 rats, individually kept in metabolic cages, received a raw red kidney bean-based diet for 10 d, and 5 of them also received a daily folic acid supplement (160 microg/g feed) both during and for 10 d before the experiment. The faecal weight was measured and a quantitative aerobic bacterial culture of the small intestinal mucosal scrapings and of the mesenteric lymph nodes was made. Folic acid supplementation did not reduce faecal output nor did it prevent loss of body weight associated with lectin-induced diarrhoea. However, the mean total count of enteric bacteria translocated to the mesenteric lymph nodes was significantly reduced in the supplemented rats (1.27 +/- 0.61 vs 2.66 +/- 0.84, p = 0.028) and a trend towards reduced bacterial count in the small intestinal mucosal scrapings (0.40 +/- 0.89 vs 1.42 +/- 1.31, p = 0.16) was documented. A significant positive correlation was also seen between the bacterial count in the jejunal mucosal scrapings and in the mesenteric lymph nodes. CONCLUSION: Although large-dose folic acid supplementation did not prevent diarrhoea and malnutrition induced by a lectin-based diet, it substantially reduced the count of enteric bacteria translocated into the mesenteric lymph nodes and showed a trend towards a reduction in indigenous bacteria adhering to jejunal mucosa. These findings could be of relevance in the prevention of septicaemic complications following many clinical conditions, including diarrhoea with malnutrition in children known to have bacteraemic and septicaemic complications.


Assuntos
Translocação Bacteriana/efeitos dos fármacos , Diarreia/microbiologia , Diarreia/prevenção & controle , Suplementos Nutricionais , Ácido Fólico/farmacologia , Linfonodos/efeitos dos fármacos , Animais , Fenômenos Fisiológicos Bacterianos , Contagem de Colônia Microbiana , Dieta , Modelos Animais de Doenças , Feminino , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Linfonodos/microbiologia , Masculino , Mesentério , Projetos Piloto , Probabilidade , Ratos , Ratos Endogâmicos LEC , Valores de Referência , Sensibilidade e Especificidade
2.
Jpn J Pharmacol ; 85(2): 133-8, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11286394

RESUMO

Prostaglandin (PG) and nitric oxide (NO) have been known to inhibit the lesion formation induced by necrotic agents. However, no clear correlation between PG and NO has been shown in the gastroprotective action against necrotic agent-induced gastric mucosal lesions in rats. Thus, the present study was performed to clarify this correlation. Gastric mucosal lesions were induced by the oral administration of 0.6 M HCl in rats. 16,16-Dimethyl PGE2 (0.3-3 microg/kg, p.o.; dim-PGE2), sodium nitrite (0.3 and 1 mg/kg, s.c.) and sodium nitroprusside (30 and 100 microg/kg, i.v.; SNP) dose-dependently inhibited the lesion formation. Orally administered sodium nitrite or SNP (3 mg/kg) also significantly inhibited the lesion formation. The gastroprotective action by dim-PGE2 was not affected by the pre-treatment with N(G)-nitro-L-arginine methylester (10 mg/kg, i.v.). The gastroprotective effect by sodium nitrite or SNP was markedly attenuated by the pre-treatment with indomethacin (10 mg/kg, s.c.). These findings suggest that NO donating compounds inhibit the HCl-induced mucosal lesions mainly through prostaglandin, but dim-PGE2 directly inhibits the lesions without involvement of NO in rats.


Assuntos
16,16-Dimetilprostaglandina E2/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Ácido Clorídrico/toxicidade , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Nitrito de Sódio/farmacologia , Úlcera Gástrica/prevenção & controle , Administração Oral , Animais , Mucosa Gástrica/metabolismo , Ácido Clorídrico/administração & dosagem , Ácido Clorídrico/antagonistas & inibidores , Indometacina/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Úlcera Gástrica/metabolismo
4.
Jpn J Pharmacol ; 82(2): 168-70, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10877537

RESUMO

Nitric oxide (NO) is involved in the mechanism of castor oil-induced diarrhea. This study was performed to elucidate the source of NO. Diarrhea was induced by oral administration of castor oil in rats. Diarrhea was significantly inhibited by the pre-treatment with a relatively selective nerve NO synthase inhibitor, 7-nitroindazole. This effect was attenuated by the treatment with L-arginine. Capsaicin-sensitive afferent nerve degeneration did not affect the diarrhea. N(G)-Nitro-L-arginine methylester significantly inhibited diarrhea even in capsaicin-pretreated rats. These data suggest, at least in part, the involvement of NO from nerves on the diarrhea induced by castor oil in rats.


Assuntos
Óleo de Rícino/toxicidade , Diarreia/induzido quimicamente , Óxido Nítrico/fisiologia , Animais , Relação Dose-Resposta a Droga , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Sprague-Dawley
7.
Nihon Yakurigaku Zasshi ; 110(2): 77-82, 1997 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-9306416

RESUMO

To clarify the mechanism of castor oil-induced diarrhea, this study was performed by using rats in relation to nitric oxide (NO) and prostaglandin (PG). Castor oil induced diarrhea in all rats within 3 hr in the control group. The pretreatment of NG-nitro-L-arginine methyl ester prevented the diarrhea, and this effect was attenuated by the combined treatment of L-arginine. Amino-guanidine inhibiting inducible NO synthase had no effect on the diarrhea, but dexamethasone, an inhibitor of both inducible NO synthase and phospholipase A2 that synthesizes PGs, significantly prevented it. Indomethacin, an inhibitor of cyclooxygenase that synthesizes PGs, also significantly prevented diarrhea. Therefore, the mechanism of the preventive effect by dexamethazone on diarrhea was suggested to be the inhibition of PGs generation. From the above results, it became clear that PG and NO, especially that synthesized by constitutive NO synthase, are involved in the mechanism of diarrhea induction by castor oil in rats.


Assuntos
Óleo de Rícino , Catárticos , Diarreia/induzido quimicamente , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico/fisiologia , Prostaglandinas/fisiologia , Animais , Dexametasona/farmacologia , Guanidinas/farmacologia , Indometacina/farmacologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley
8.
Am J Clin Nutr ; 63(5): 741-5, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8615358

RESUMO

We examined the correlation between the incidence of Crohn disease and dietary change in a relatively homogeneous Japanese population. The incidence and daily intake of each dietary component were compared annually from 1966 to 1985. The univariate analysis showed that the increased incidence of Crohn disease was strongly (P < 0.001) correlated with increased dietary intake of total fat (r = 0.919). animal fat (r = 0.880), n-6 polyunsaturated fatty acids (r = 0.883), animal protein (r = 0.908), milk protein (r = 0.924), and the ratio of n-6 to n-3 fatty acid intake (r = 0.792). It was less correlated with intake of total protein (r = 0.482, P < 0.05), was not correlated with intake of fish protein (r = 0.055, P > 0.1), and was inversely correlated with intake of vegetable protein (r = -0.941, P < 0.001). The multivariate analysis showed that increased intake of animal protein was the strongest independent factor with a weaker second factor, an increased ration of n-6 to n-3 polyunsaturated fatty acids. The present study in association with reported clinical studies suggests that increased dietary intake of animal protein and n-6 polyunsaturated fatty acids with less n-3 polyunsaturated fatty acids may contribute to the development of Crohn disease.


Assuntos
Doença de Crohn/epidemiologia , Doença de Crohn/etiologia , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Ácidos Graxos Insaturados/administração & dosagem , Adulto , Doença de Crohn/fisiopatologia , Dieta/normas , Gorduras na Dieta/efeitos adversos , Proteínas Alimentares/efeitos adversos , Ácidos Graxos Ômega-6 , Ácidos Graxos Insaturados/efeitos adversos , Feminino , Humanos , Incidência , Japão/epidemiologia , Masculino , Análise Multivariada
9.
J Gastroenterol ; 30 Suppl 8: 91-4, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8563902

RESUMO

Crohn's disease (CD) often flares up and requires frequent hospitalization and/or surgery. Cyclic home elemental enteral alimentation (C-HEEA) was developed to prevent flare-up of CD and to minimize patient hospitalization. However, its therapeutic efficacy has not been studied in a large patient population. Therefore, questionnaires were sent to members of the Inflammatory Bowel Disease (IBD) Research Group of Japan to evaluate the therapeutic efficacy of C-HEEA and to define the factors that may affect the efficacy of the treatment. Data for 410 patients (C-HEEA-treated n = 322; drug-treated n = 88) were collected from 29 institutions and analysis showed the following results. The cumulative remission and non-hospitalization rates of the C-HEEA treated group were significantly higher than the rates of the drug-treated group in all patients and in those with ileitis and ileo-colitis (P < 0.0001, P < 0.001, and P < 0.01, respectively), but no significant difference was noted in patients with colitis. Cumulative remission and non-hospitalization rates were also influenced by the daily calorie content of the elemental diet (ED); more than 1200 kcal of the ED per day was found to be more effective than lower amounts to maintain remission and to prevent hospitalization. The therapeutic efficacy of C-HEEA was shown to be superior to that of drug treatment in patients with CD with ileal involvement, and it is suggested that more than 1200kcal per day should be supplied by the ED to enhance its therapeutic efficacy.


Assuntos
Doença de Crohn/terapia , Nutrição Enteral , Alimentos Formulados , Serviços de Assistência Domiciliar , Estudos de Casos e Controles , Doença de Crohn/epidemiologia , Ingestão de Energia , Hospitalização/estatística & dados numéricos , Humanos , Japão/epidemiologia , Indução de Remissão , Inquéritos e Questionários , Resultado do Tratamento
10.
J Gastroenterol ; 30 Suppl 8: 98-101, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8563904

RESUMO

We investigated the therapeutic efficacy of n-3 polyunsaturated fatty acids (PUFAs) on trinitro-benzene sulfonic acid (TNBS)-induced colitis in the rats, which condition is considered an experimental Crohn's disease (CD). In rats with TNBS-induced colitis, feeding with an elemental diet (ED) plus 2% n-3 PUEA-rich perilla oil significantly suppressed plasma leukotriene (LT) B4 and ulcer index compared to that in rats fed with ED plus 2% n-6 PUFA-rich safflower oil (34.2 +/- 12.3 s 63.8 +/- 13.2 pg/ml and 8.8 +/- 12.1 vs 66.4 +/- 33.1, P < 0.01, respectively). Moreover, the plasma LTB4 and the ulcer index were significantly correlated (P < 0.05). Feeding with ED plus 2% alpha-linolenic acid (A-LA)-rich vegetable oil significantly reduced plasma LTB4 and colonic weight compared to that in rats fed with ED plus 2% eicosapentaenoic acid (EPA)/docosahexaenonic acid (DHA)-rich fish oil in this model (61.6 +/- 10.5 vs 85.0 +/- 20.9 pg/ml and 0.83 +/- 0.13 vs 0.96 +/- 0.08g, P < 0.05, respectively). This study suggested that dietary fat manipulation with perilla oil can reduce colonic damage and that this is correlated with the suppression of plasma LTB4. The therapeutic efficacy of A-LA in controlling intestinal inflammation in experimental CD may be superior to that of EPA and DHA.


Assuntos
Doença de Crohn/terapia , Ácidos Graxos Ômega-3/uso terapêutico , Alimentos Formulados , Animais , Colite/induzido quimicamente , Colo/patologia , Doença de Crohn/induzido quimicamente , Óleos de Peixe/uso terapêutico , Leucotrieno B4/sangue , Masculino , Tamanho do Órgão , Ratos , Ratos Sprague-Dawley , Óleo de Cártamo/uso terapêutico , Ácido Trinitrobenzenossulfônico , Ácido alfa-Linolênico/uso terapêutico
11.
Gut ; 36(3): 379-81, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7698696

RESUMO

Red kidney beans were fed to weanling Long-Evans rats to cause diarrhoea (mean (SD) faecal wet weight: 2.66 (0.73) g/day in six rats fed beans v 1.12 (0.47) g/day in six control rats, p < 0.01) and increased faecal energy loss (4.87 (0.41) v 2.14 (0.23) kcal/day, p < 0.01). In addition, the rats fed beans had heavier small intestines (80.6 (4.6) v 51.9 (8.4) g/kg body weight, p < 0.01), heavier mesenteric lymph nodes (0.72 (0.27) v 0.08 (0.08) g/kg body weight, p < 0.05), and translocation of indigenous intestinal bacteria, Citrobacter Spp and Escherichia coli, to the mesenteric lymph nodes. (Translocation positive, that is, > 100 colonies per g of nodal tissue: 75% v 0%, p < 0.005.) These data suggest that diarrhoea induced by red kidney beans is a suitable model for studies of an important cause of persistent diarrhoea--that is, systemic complications. This rat model of lectin induced diarrhoea with translocation of intraluminal enteric bacteria into mesenteric lymph nodes should be useful in understanding the well known septicaemic complications associated with prolonged diarrhoea in infants and small children and in studies on factors that may modify or prevent bacterial translocation.


Assuntos
Diarreia/microbiologia , Modelos Animais de Doenças , Animais , Contagem de Colônia Microbiana , Diarreia/etiologia , Linfonodos/microbiologia , Mesentério , Fito-Hemaglutininas , Ratos , Ratos Endogâmicos , Desmame
12.
Urol Int ; 51(3): 129-32, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8249222

RESUMO

A study was conducted to assess the clinical and microbiological effects of antimicrobial treatment for chronic prostatitis as a means of defining the role of Ureaplasma urealyticum. Significant U. urealyticum cells were considered to be isolated from the prostates of 18 of 143 prostatitis patients. These patients with ureaplasma-associated prostatitis were randomly treated with either ofloxacin or minocycline for 2 weeks; 4 patients were excluded due to voluntary withdrawal. U. urealyticum was eradicated in all the patients. Symptoms were resolved in 10 patients, and leukocytes in expressed prostatic secretion were cleared in 4 patients; both drug treatments revealed similar results. Even if we exclude 3 patients with significant coexistent Staphylococcus epidermidis cells before treatment, 3 of 11 patients evaluated showed complete resolution of symptoms and clearance of leukocytes in expressed prostatic fluid. These results suggest that U. urealyticum is a causative organism in some patients with chronic prostatitis.


Assuntos
Minociclina/uso terapêutico , Ofloxacino/uso terapêutico , Prostatite/tratamento farmacológico , Infecções por Ureaplasma/tratamento farmacológico , Ureaplasma urealyticum , Adulto , Idoso , Doença Crônica , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Prostatite/sangue , Prostatite/microbiologia , Infecções por Ureaplasma/sangue , Ureaplasma urealyticum/isolamento & purificação
13.
Int Urol Nephrol ; 25(1): 45-9, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8514473

RESUMO

A case of renal medullary fibroma in a woman is presented. A CT scan, which was performed for examination of cholelithiasis, incidentally revealed a mass in the left renal pelvis, and retrograde pyelography showed a filling defect in the same site. Left nephrectomy was performed. Histological examination revealed a renal medullary fibroma. The diagnostic and therapeutic dilemmas associated with this condition are discussed.


Assuntos
Fibroma/epidemiologia , Medula Renal/patologia , Neoplasias Renais/epidemiologia , Idoso , Feminino , Fibroma/diagnóstico por imagem , Humanos , Neoplasias Renais/diagnóstico por imagem , Nefrectomia , Tomografia Computadorizada por Raios X , Urografia
14.
Biochemistry ; 31(12): 3236-43, 1992 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-1372826

RESUMO

A number of cell surface proteins have been shown to be anchored to the plasma membrane by a covalently attached glycoinositol phospholipid (GPL) in amide linkage to the C-terminus of the mature protein. We applied several criteria to establish that folate binding protein (FBP) in brush border membranes of rat kidney contains a GPL anchor. Brush border membranes were isolated and labeled with [3H]folate, and the complex of FBP and [3H]folate was shown to be released to the supernatant by incubation with purified bacterial phosphatidylinositol-specific phospholipase C (PIPLC) but not by incubation with a purified bacterial phosphatidylcholine-specific phospholipase C. The FBP-[3H]folate complex both in crude extracts and after FBP purification by ligand-directed affinity chromatography interacted with Triton X-114 micelles, and prior incubation with PIPLC prevented this detergent interaction. Individual residues characteristic of GPL anchors were found to be covalently associated with FBP following polyacrylamide gel electrophoresis in sodium dodecyl sulfate. These included glucosamine and ethanolamine, which were radiolabeled by reductive methylation and identified by chromatography on an amino acid analyzer, and inositol phosphate, which was inferred by Western blotting with an anti-CRD antisera. This antisera gave positive immunostaining only after FBP had been cleaved by PIPLC, a reliable diagnostic of a GPL anchor. The relationship between GPL-anchored FBP in biological membranes and soluble FBP in biological fluids also is discussed.


Assuntos
Proteínas de Transporte/química , Ácido Fólico/química , Glicolipídeos/análise , Rim/ultraestrutura , Fosfatidilinositóis/análise , Receptores de Superfície Celular , Animais , Proteínas de Transporte/efeitos dos fármacos , Proteínas de Transporte/isolamento & purificação , Bovinos , Reações Cruzadas , Detergentes , Epitopos/imunologia , Receptores de Folato com Âncoras de GPI , Glicolipídeos/imunologia , Glicosilfosfatidilinositóis , Humanos , Hidrólise , Soros Imunes , Rim/efeitos dos fármacos , Rim/enzimologia , Metilação , Microvilosidades/química , Microvilosidades/efeitos dos fármacos , Microvilosidades/enzimologia , Octoxinol , Fosfatidilinositol Diacilglicerol-Liase , Fosfatidilinositóis/imunologia , Fosfoinositídeo Fosfolipase C , Fosfolipases , Diester Fosfórico Hidrolases , Polietilenoglicóis , Ratos
15.
Br J Urol ; 66(1): 22-5, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2203501

RESUMO

The clinical significance of the antibody-coated bacteria (ACB) test was evaluated with urine from 20 patients with candiduria. The relationship between the in vitro antibody-coating test for Candida albicans, urinary immunoglobulin (Ig) levels and serum antibody titres was evaluated in 40 patients without candiduria, 23 of whom had bacterial urinary tract infection (UTI). Urine specimens from 19 of the 20 patients with candiduria gave a positive result regardless of clinical symptoms; 12/23 specimens of urine from patients with bacterial UTI were positive for antibody-coated C. albicans cells, but there were no positive samples in the patients without UTI. All of the coating-positive patients had serum antibody titres greater than or equal to 1:160, the class of antibody being dependent on the urinary Ig levels. The ACB test for candiduria is of little clinical value in indicating invasive Candida UTI as the Candida cells appear to adhere to antibodies in urine contaminated with circulating fluids.


Assuntos
Teste na Urina com Bactérias Cobertas por Anticorpos , Candidíase/diagnóstico , Imunofluorescência , Infecções Urinárias/diagnóstico , Idoso , Anticorpos Antifúngicos/análise , Bacteriúria/diagnóstico , Candida albicans/imunologia , Feminino , Humanos , Imunoglobulinas/urina , Masculino
16.
Hinyokika Kiyo ; 36(6): 741-5, 1990 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-1700587

RESUMO

Diffusion of ofloxacin (OFLX) into prostatic tissue was studied in 31 patients with benign prostatic hypertrophy. Concentrations of OFLX in the serum and prostatic tissue were measured at scheduled intervals after 200 mg OFLX oral administration. The mean OFLX level in prostatic tissue and tissue/serum ratio at 2 hours, 4 hours and 6 hours was 3.33 +/- 0.96 micrograms/g (1.25 +/- 0.28) in 10 patients, 2.21 +/- 0.55 micrograms/g (0.92 +/- 0.32) in 9 patients and 2.10 +/- 0.99 micrograms/g (1.01 +/- 0.23) in 12 patients, respectively. OFLX levels in prostatic tissue covered the minimum inhibitory concentration for several pathogenic bacteria detected from the infected prostatic fluid. Therefore, OFLX was thought to be a very useful drug for the treatment of bacterial prostatitis and postoperative infection of prostatic surgery.


Assuntos
Ofloxacino/farmacocinética , Próstata/metabolismo , Hiperplasia Prostática/metabolismo , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Ofloxacino/administração & dosagem , Ofloxacino/sangue
17.
Biochim Biophys Acta ; 1024(2): 331-5, 1990 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-2354183

RESUMO

A mildly acidic pH in the lumen of the small intestine markedly enhances the transport of folate. This study investigated the relationship between pH and the affinity between folic acid and the apical membrane transporter using brush border membrane vesicles from rat jejunum and differentiated monolayer cultures of the colon carcinoma cell line, CaCo-2. Uptake studies with BBMV were conducted at folic acid concentrations of 0.1 to 50 mumol/l, conditions which were suitable for analyzing uptake data based on the Michaelis-Menten equation modified to include a nonsaturable component. These analyses yielded apparent Km values of 0.6 and 12.3 microM at pH 5.5 and pH 7.4, respectively (P less than 0.05). Values for Vmax were lower at pH 5.5 than at pH 7.4 (0.8 vs. 1.6 pmol/mg protein per 10 s, P less than 0.05). The studies with CaCo-2 cells employed folic acid concentrations of 0.1 to 5 mumol/l. Under these conditions the apparent Km for folic uptake was lowest at pH 6.0, where the Km was 0.7 mumol/l. The apparent Km increased sharply as a neutral pH was approached; reaching a value of 13.9 mumol/l at pH 7.1. These data suggest that the prominent pH effect on intestinal folate transport is, in part, explained by an increased affinity of the folate substrate for its membrane transporter.


Assuntos
Ácido Fólico/metabolismo , Intestino Delgado/metabolismo , Animais , Transporte Biológico , Concentração de Íons de Hidrogênio , Jejuno/metabolismo , Cinética , Microvilosidades/metabolismo , Ratos , Ratos Endogâmicos , Células Tumorais Cultivadas
18.
J Nutr Biochem ; 1(5): 257-61, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-15539213

RESUMO

Binding of [(3)H]folic acid by isolated rat jejunal brush border membranes (BBMs) was analyzed by chromatography on small Biogel P-30 columns. Folic acid binding to BBMs exhibited a prominent pH effect with a sharp maximum at pH 5.5 to 6.0. After acid treatment to strip the BBMs of bound folate, the membranes demonstrated a wider pH optimum (5.5 to 7.5) of folate binding and a higher binding capacity. Scatchard analysis of binding experiments performed at pH 6.0 revealed the existence of two components: one with a high affinity (kd = 12 to 25 nM) and low capacity (V(max) for non-acidified BBMs = 0.259 to 0.264 pmol/mg protein, V(max) for acidified BBMs = 0.41 to 0.71 pmol/mg protein) and the other with a low affinity (kd = 1.1 to 5.1 microM and high capacity (V(max) for non-acidified BBMs = 0.93 to 1.93 pmol/mg protein, V(max) for acidified BBMs = 4.05 to 7.69 pmol/mg protein). Phosphatidylinositol-specific phospholipase C preferentially detached the high affinity component from jejunal BBMs. Phosphatidylinositol-specific phospholipase C-released folate binding protein was precipitated by antibodies to the high-affinity folate-binding protein from rat kidney. These data suggest the existence of two different folate-binding proteins in isolated rat jejunal BBMs. The high-affinity folate-binding protein shares epitopes with the folate-binding protein in the kidney.

19.
Clin Pharmacol Ther ; 44(6): 690-8, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2904311

RESUMO

To study the concentration-response relationship of famotidine, we serially monitored intragastric pH and measured plasma drug concentrations simultaneously after an intravenous injection of this H2-receptor antagonist (0.1 mg/kg) in eight patients with upper gastrointestinal bleeding and in six healthy subjects. By applying the sigmoidal Emax model the mean (+/- SD) plasma famotidine concentrations associated with an intragastric pH of 4.0 in patients and healthy subjects were estimated to be 17.7 +/- 10.7 and 24.8 +/- 10.3 ng/ml, respectively (not significantly different). No significant differences were observed in the mean pharmacokinetic parameters between the two study groups. Multiple regression analysis revealed that not only a pharmacokinetic factor (i.e., elimination t1/2) but also a pharmacodynamic (or sensitivity) factor (i.e., a drug concentration associated with an intragastric pH of 4.0) contributed significantly (p less than 0.01) to the overall variability in the duration of antisecretory effect in our study subjects, with standardized partial regression coefficients of 0.54 and -0.63, respectively. Based on these data, we predict that around-the-clock control of a fasting intragastric pH above 4.0 can be attained by a continuous infusion of famotidine at rates ranging from 6 to 25 mg/day (mean +/- SD, 11 +/- 7 mg/day) in a 70 kg patient whose pharmacokinetic and pharmacodynamic characteristics are similar to those of our patients.


Assuntos
Ácido Gástrico/metabolismo , Hemorragia Gastrointestinal/metabolismo , Antagonistas dos Receptores H2 da Histamina/sangue , Tiazóis/sangue , Adulto , Relação Dose-Resposta a Droga , Famotidina , Feminino , Determinação da Acidez Gástrica , Mucosa Gástrica/efeitos dos fármacos , Meia-Vida , Antagonistas dos Receptores H2 da Histamina/farmacocinética , Antagonistas dos Receptores H2 da Histamina/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Tiazóis/farmacocinética , Tiazóis/farmacologia
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