RESUMO
AIMS: Our main goal is to study the effects on the carbohydrate metabolism. Thus, we designed various experimental surgical models on healthy non-obese Wistar rats to reproduce several conditions. In this sense, we report a new experimental model. It is well known that bariatric surgery has important effects on the control of Type 2 Diabetes Mellitus. The underlying reasons are yet unknown, although the different theories focused in the release of different hormones after the pass of the nutrients through the tract. These released hormones have opposite effects that come together in a balanced glycemic metabolism. MATERIALS AND METHODS: After bariatric surgical techniques, the modified anatomy resulted in an imbalance of the secreted hormones. Wistar rats were randomized in two groups Sham and surgical group. Our model consisted on the transposition of the terminal ileum right after the pylorus. Weight gain, food intake, and basal glycemia were measured weekly. RESULTS: We did not obtain significant differences between both groups for these functional variables. CONCLUSIONS: This technique involved an early pass of the bolus through the ileum. The change on the luminal pH, along with the lack of enzymes to absorb the content, or the changes in the release of several hormones must be variables to the study. The mortality rate was assumable considering it was an experimental model on animals.
OBJETIVO: Crear un nuevo modelo quirúrgico experimental en ratas Wistar sanas no obesas para estudiar los efectos del metabolismo glucídico. Es bien sabido que las técnicas de cirugía bariátrica tienen un efecto importante sobre la resolución de la diabetes mellitus tipo 2. Se han invocado diferentes hipótesis, algunas centradas en el papel que tienen distintas hormonas secretadas por el propio tubo digestivo tras el paso de los nutrientes a su través, pero las razones últimas subyacentes permanecen desconocidas. El efecto contrapuesto de dichas hormonas consigue un efecto de control glucémico. El desequilibrio hormonal tras las alteraciones anatómicas de las cirugías bariátricas podría estar en la base de dicha mejora del metabolismo glucídico final. MATERIAL Y MÉTODOS: Las ratas fueron operadas en dos grupos (control quirúrgico y experimental) y se procedió a disponerles el íleon anastomosado al antro pilórico, previo al esfínter pilórico. Medimos distintos parámetros funcionales (ganancia de peso, ingesta y glucemias semanales). RESULTADOS: No obtuvimos diferencias significativas en la evolución de estos parámetros. CONCLUSIONES: Este modelo será útil para nuestro propósito de estudiar el íleon, en su componente secretor de enterohormonas, cuando el paso de los nutrientes se produzca tempranamente. La mortalidad fue asumible, dada la innovación técnica realizada.
Assuntos
Glicemia/metabolismo , Duodeno/cirurgia , Trânsito Gastrointestinal/fisiologia , Íleo/cirurgia , Modelos Animais , Anastomose Cirúrgica/métodos , Anastomose Cirúrgica/mortalidade , Animais , Cirurgia Bariátrica/métodos , Cirurgia Bariátrica/mortalidade , Glicemia/análise , Metabolismo dos Carboidratos , Diabetes Mellitus Tipo 2/metabolismo , Duodeno/fisiologia , Ingestão de Alimentos , Íleo/fisiologia , Incretinas/metabolismo , Masculino , Piloro/fisiologia , Distribuição Aleatória , Ratos , Ratos Wistar , Aumento de PesoRESUMO
Hydrogen sulphide (H(2)S) has shown to relax gastrointestinal muscle. Here in, we evaluated the effects of H(2)S donors on gastric emptying and in pyloric sphincter muscle relaxation, and whether these effects involved K(ATP) channels or TRPV1 receptors. Mice were treated with l-cysteine (alone or with propargylglycine-an inhibitor of H(2)S synthesis), NaHS, Lawesson's reagent (H(2)S donors) or saline. After 30 min, mice were gavaged with a liquid meal containing a nonabsorbable marker and then killed at 10, 20 or 30 min intervals to assess marker recovery from the stomach and intestine. This experiment was repeated in mice pre-treated with K(ATP) channel (glibenclamide) or TRPV1 receptor (capsazepine) antagonists. In addition, pyloric sphincter muscles were mounted in an organ bath, incubated with saline, glibenclamide or capsazepine, and NaHS dose-responses were determined. H(2)S donors and l-cysteine enhanced gastric emptying in a dose-dependent manner; propargylglycine reversed the effect of l-cysteine. Both glibenclamide and capsazepine abolished l-cysteine and H(2)S donors' augmentation of gastric emptying. Dose-dependent inductions of pyloric sphincter relaxation by NaHS were abolished by glibenclamide or capsazepine. These data suggest that H(2)S donors-induced acceleration of gastric emptying and relaxation of pyloric sphincter muscle by K(ATP) channel and TRPV1 receptor activations.
Assuntos
Esvaziamento Gástrico/fisiologia , Sulfeto de Hidrogênio , Canais KATP/fisiologia , Canais de Cátion TRPV/fisiologia , Animais , Capsaicina/análogos & derivados , Capsaicina/farmacologia , Esvaziamento Gástrico/efeitos dos fármacos , Glibureto/farmacologia , Canais KATP/antagonistas & inibidores , Masculino , Camundongos , Relaxamento Muscular/efeitos dos fármacos , Bloqueadores dos Canais de Potássio/farmacologia , Piloro/efeitos dos fármacos , Piloro/fisiologia , Canais de Cátion TRPV/antagonistas & inibidoresRESUMO
This study was aimed to clarify the mechanisms of gastroprotection by centipedic acid (CPA), a natural diterpene from Egletes viscosa LESS. (Asteraceae) using ethanol-induced gastric mucosal damage in mice and gastric secretion in 4-h pylorus-ligated rats as model systems. In mice, intragastrically administered CPA (25, 50, 100 mg/kg) greatly reduced the mucosal lesions induced by 96% ethanol (0.2 ml, p.o.) by 18, 53, and 79%, respectively, whereas N-acetylcysteine (NAC, 300 mg/kg, i.p.), the reference compound produced a 50% inhibition. In 4-h pylorus-ligated rats, CPA (50 mg/kg) applied intraduodenally decreased both gastric secretory volume and total acidity. Similar to NAC, the plant diterpene effectively prevented the ethanol associated decrease in non-proteic sulfhydryls (NP-SH) and the elevated thiobarbituric acid-reactive substances (TBARS) in gastric tissue, suggesting that these compounds exert an antioxidant effect. Pretreatment of mice with indomethacin, the cyclooxygenase inhibitor but not with capsazepine, the transient receptor potential vanilloid-1 (TRPV1)-receptor antagonist greatly suppressed the gastroprotective effect of CPA. Furthermore, CPA gastroprotection was significantly attenuated in mice pretreated with L-NAME or glibenclamide the respective inhibitors of nitric oxide synthase and K(+)(ATP) channel activation. These data suggest that CPA affords gastroprotection by different and complementary mechanisms, which include a sparing effect on NP-SH reserve, and roles for endogenous prostaglandins, nitric oxide, and TRPV1-receptor and K(+)(ATP) channel activation.
Assuntos
Antiulcerosos , Asteraceae/química , Diterpenos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Furanos/farmacologia , Acetilcisteína/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Capsaicina/farmacologia , Depressores do Sistema Nervoso Central , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Etanol , Sequestradores de Radicais Livres/farmacologia , Mucosa Gástrica/patologia , Glibureto/farmacologia , Hipoglicemiantes/farmacologia , Indometacina/farmacologia , Masculino , Camundongos , NG-Nitroarginina Metil Éster/farmacologia , Neurônios Aferentes/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Piloro/fisiologia , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Úlcera Gástrica/prevenção & controle , Compostos de Sulfidrila/farmacologia , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
Literature has been showing a tendency of reducing the limits of Whipple's resection. The main technical advance was the pylorus preserving resection, technique proposed by Traverso and Longmire in 1978. The pancreticoduodenectomy for chronic pancreatitis, is probably the best opportunity to apply this type of procedure. In these specific patients, the author preserved the pylorus and the third portion of the duodenum. The gastrointestinal transit was reconstructed by the duodenumduodenal anastomosis and the bile duct and the pancreas were drained in a Roux-en-way loop. Follow-up showed no important complication, with no problems related to gastric emptying and without pain
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Anastomose Cirúrgica , Pancreaticoduodenectomia , Pancreatite/complicações , Piloro/fisiologia , Doença CrônicaRESUMO
The aerial parts of Artemisia douglasiana have been used in folk medicine as a cytoprotective agent against the development of peptic ulcer. Dehydroleucodine [1], its active principle, significantly prevents the formation of gastric lesions induced by the exposure of the rats to absolute ErOH. It was found in this study that (a) pretreatment of rats with 1 (40 mg/kg, po) caused a significant increase in glycoprotein synthetic activity, approximately sevenfold as large as that of the control; and (b) pretreatment of the rats with the thiol reagent N-methylmaleimide (NEM) significantly diminished the cytoprotection provided by 1. However, the protective effect of 1 was not totally abolished by pretreatment with a combination of indomethacin and NEM, indicating additional mechanisms are involved in the cytoprotective action of 1.
Assuntos
Antiulcerosos/farmacologia , Mucosa Gástrica/metabolismo , Lactonas/farmacologia , Muco/metabolismo , Sesquiterpenos/farmacologia , Compostos de Sulfidrila/metabolismo , Animais , Antiulcerosos/antagonistas & inibidores , Etanol , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Indometacina/farmacologia , Lactonas/antagonistas & inibidores , Masculino , Muco/efeitos dos fármacos , Plantas Medicinais/química , Piloro/fisiologia , Ratos , Ratos Wistar , Sesquiterpenos/antagonistas & inibidores , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Úlcera Gástrica/prevenção & controleRESUMO
The aim of the present study was to investigate in vitro the effect of NG-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor, on neurogenic relaxation of human lower esophageal sphincter (LES) and distal pylorus (DP) circular muscle strips induced by electrical field stimulation (EFS). Muscle strips obtained from 5 patients who underwent total gastrectomy were suspended in 10-ml organ baths containing Krebs solution for recording isometric tension. L-NAME (30 microM) reduced the amplitude of the EFS-induced relaxation by 85 +/- 9% (N = 3) in the LES and by 52 +/- 16% (N = 3) in the DP but did not affect sodium nitroprusside-induced relaxation. L-Arginine (300 microM) partially reversed the L-NAME inhibition in the LES and totally in the DP. These findings suggest a role for L-arginine-derived NO in the nerve-mediated NANC relaxation of the human LES and DP.
Assuntos
Relaxamento Muscular/fisiologia , Músculo Liso/fisiologia , Óxido Nítrico/fisiologia , Adulto , Arginina/análogos & derivados , Arginina/farmacologia , Estimulação Elétrica , Junção Esofagogástrica/efeitos dos fármacos , Junção Esofagogástrica/fisiologia , Feminino , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , NG-Nitroarginina Metil Éster , Óxido Nítrico/antagonistas & inibidores , Piloro/efeitos dos fármacos , Piloro/fisiologiaRESUMO
Gastric secretion was studied in two groups of rats in which pyloric ligature was made according to Dai's method. Both groups were put in a hypopressure chamber. One of the groups was normovolemic. The other group was made hypovolemic by acute bleeding. The following parameters were checked in gastire contents: volumen, acid and pepsin secretion, U.P./g. of stomach, chloride, potassium and sodium; in gastric mucosa total U.P. and pepsinogen concentration were measured. In the rats subjected to acute hypovolemia and hypoxia it was found a significant decrease in acid secretion, chloride and potassium mEq/1; there were no statistically significant changes in volume, pepsin secretion; U.P./g. of stomach and sodium mEq/1. Total U. P. and U.P./. of stomach increased in the gastirc mucosa.
Assuntos
Volume Sanguíneo , Suco Gástrico/metabolismo , Hipóxia/fisiopatologia , Piloro/fisiologia , Animais , Cloretos/análise , Feminino , Suco Gástrico/análise , Mucosa Gástrica/análise , Ligadura , Masculino , Pepsina A/análise , Pepsinogênios/análise , Potássio/análise , RatosRESUMO
A comparative study of gastric secretion in rats with pyloric ligature according to either Shays' or Dais' methods was carried on, studying in both groups gastic acid and peptic secretions, mucous pepsinogen, and Na+, K+, and Cl-. The acid-peptic output as well as gastric Pu/g were greater in Dais' method. There were no changes regarding mucous pepsinogen when comparing both methods. Cl- and Na+ determinations showed minimal changes, whereas K+ showed no difference in both methods. We explain these modifications based on the difference in the secreted volume, since the acid concentration and Pu/ml are practically the same when comparing both methods.