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D Celener

Publications and source records attributed to D Celener.

At least 19 recordsLinked to original sources
PubMed1998

Offspring of streptozotocin diabetic rats: size changes in Langerhans islets with time after birth.

It has been demonstrated that, in the diabetic rat, pregnancy and lactation are severely altered: in this study, we have measured the size of Langerhans islets of rat pups, the offspring of experimental diabetic mothers and nondiabetic controls. Diabetes was induced through streptozotocin administration (dose, 60 mg/kg body wt.). This drug was injected in every animal; their blood sugar was measured 1 week later (Haemo-Glukotest, Boehringer Mannheim), and they were then separated into three groups according to their fasting blood sugar levels: (a) severe diabetics (above 16.5 mM/l); (b) mild diabetics (6.5-16.5 mM/l); and (c) nondiabetic normals. They received insulin therapy (2-4 I.U./day) as the mild diabetics exhibited a slightly higher than normal fasting blood sugar, and the diabetic ones, above 15 mM/l. The areas of Langerhans islets of pups were measured 1 and 5 days after parturition; pancreas sections were dyed (haematoxylin-eosin) and morphometry was then performed using a digitalized magnetic tabloid connected to a Zeiss Morphomat 30 (Kontron). On the first day after parturition, the pancreas section areas in pups from mildly and severely diabetic mothers were smaller than those in neonates from nondiabetic controls (P < 0.001). The areas in neonates from severely diabetic mothers showed a more intense decrease than those from mildly diabetic animals (P < 0.01). On day 5 after delivery, the areas of Langerhans islets in offspring from normal mothers decreased and those in pups from diabetic mothers tended to normalize (P < 0.01), particularly those from the severely sick group (P < 0.01). We conclude that after parturition the offspring is no longer exposed to the high blood sugar levels found in both diabetic groups of mothers, thereby no hyperinsulinemia is needed; as time elapses, then, the area of their Langerhans islets tends to normalization.

Aging↗
PubMed1994

Influence of pirenzepine on colonic serotonin changes induced by short chain fatty acid.

In this work we have demonstrated the influence of a short chain fatty acid (acetate) on the number of enterochromaffin (EC) cells containing serotonin (5HT), at two different pH (pH 6.9 absorptive stimuli, and pH 2.9 secretory stimuli), infused into the colon during one hour. The number of EC cells decrease significatively, specially in the cecum with a solution of low pH (2.9). The action of piprenzepine in preventing this reduction demonstrated that was partly mediated by a cholinergic receptor mechanism. On the other hand, a decrease on the release of 5HT to the lumen was a observed under the influence of pirenzepine. We conclude that the short chain fatty acid acetate, at a low pH induces the release of serotonin through a cholinergic mechanisms indicated by the inhibition observed with antimuscarinic drug.

Acetates↗
PubMed1993

Ulex europeus agglutinin I binding pattern during chemical carcinogenesis in the rat gastrointestinal tract.

BACKGROUND: Fluorescein isothiocyanate-Ulex europeus agglutinin I stain (UEA1) was postulated as a prominent histochemical marker for premalignant mucosa in dimethylhydrazine (DMH)-treated animals. UEA1 (evaluated by two scanning methods) and high iron diamine Alcian blue (HIDAB) stain were used in attempt to detect premalignant colonic mucosa in this animal model. The authors also examined the influence of the duodenal medium on colonic segments transposed to the upper gastrointestinal tract. METHODS: Rats were placed into three groups: those with interposed intestine, those receiving the sham operation, and controls. Half of the animals received DMH, and surviving rats were killed at 2, 4, and 8 months. RESULTS: The authors found no differences in tumor development in the transposed and nontransposed colons of animals treated with DMH. Several transposed segments of animals without carcinogen induction showed dysplastic areas. These findings suggest a trophic role of certain duodenal factors in the epithelial kinetics of the transposed colons. The authors did not find HIDAB stain useful in the identification of premalignant colonic mucosa. The quantitative evaluation method of UEA1 binding was more reliable. Fifteen percent of all the colon specimens of animals without chemical induction were stained with UEA1 with this form of evaluation. Positive staining of the interposed colon samples was the most important factor for these findings. CONCLUSIONS: In this animal model, UEA1 staining is a potentially useful marker of premalignant mucosa, particularly when the nontransposed distal colon of animals treated with DMH is considered.

Animals↗
PubMed1993

Action of cisapride on rat colonic secretion.

The stimulating effect of cisapride on the motility of the digestive tract is well known. However, there are only a few studies on the influence of this drug on the absorptive or secretory activity of the colonic mucosa. In the present study, the ability of cisapride to alter the mural transport of water and electrolytes in the colon and its effects on mucus secretion and albumin permeation were studied. The effects of cisapride on the rat colon in vivo were studied under different conditions, by means of an instillation of sodium acetate solution at pH 6.9, which induced absorption of water and electrolytes, and in two models of colonic secretion, one employing the instillation of an acetic acid solution at pH 2.9 and the other, an intravenous infusion of 5-hydroxytryptamine (serotonin) 45 micrograms.kg-1.min-1 together with intracolonic instillation of sodium acetate. Cisapride (i.v.), at a dose of 0.32 mg.kg-1, in rats whose colon was instilled with sodium acetate (pH 6.9) induced an increase in sodium absorption and a reduction in water absorption. Cisapride (i.v.), at doses of 0.32, 0.64 and 1.0 mg.kg-1, inhibited the secretion of water, Na+, Cl-, and mucus and the permeation of albumin induced by acetic acid instillation or by serotonin infusion. It is concluded that the effect of cisapride on the colonic mucosa varies in accordance with the functional mucosal conditions and that this action may be of clinical importance.

Acetates↗
PubMed1993

[The effect of different lactic acid isomers in the colon of rats].

Depending on quantity and/or quality, the presence of lactic acid in the colonic lumen may be associated with metabolic damage of the colon. The influence exerted on the rat colon by the different isomers and racemic of the lactic acid, used at two extreme dilutions (20 and 100 mEq/l), has been the subject of study in this paper. The modifications on pH, water and electrolytes are associated with the absorptive/secretory action of the colonic wall. In addition, a study has been made on the influence of lactic acid on the colonic mucus and albumin permeation. Histopathologic studies of the caecum and left colon have been performed. There is a different colonic wall behaviour for each of the different isomers of the lactic and its racemic; a larger absorption of water, Na+ and Cl- for the D (-) isomer at a low concentration; its behaviour is completely opposite at high concentration. The final pH is higher when the D (-) isomer takes part; comparing the different isomers, there are small variations as far as albumin permeation is concerned. At high concentration there is a decline in Cl- absorption. The high percentage of erosions that take place especially in the caecum, where L (+) isomer can be found at high concentration, it is remarkable. The present observations suggest that the presence of lactic acid in (the) ulcerative colitis deserves great attention, especially in about the quantity and quality in which the acid can be found.

Animals↗
PubMed1993

[Influence of sodium butyrate intake on murine colonic carcinogenesis].

The role of short chain fatty acids (SCFA) in murine colonic carcinogenesis (MCC) has not yet been clarified. In rats, Freeman et al have reported an increased number of colonic tumors induced with dimethylhydrazine (DMH) and sodium butyrate in drinking water. On the other hand, Deschner et al showed that tributyrin intake did not increase MCC induced with azoxymethane. Both of them have reported high levels of fecal butyric acid with sodium butyrate and tributyrin intake. Although salt intake has been positively associated with colorectal cancer some authors do not support this association. We have evaluated the influence of right hemicolectomy (RH) (right colon as main source of SCFA) and the intake of 2%-pH 7 sodium butyrate (S.BUT) and 4 g/l sodium chloride (S.CHL) in drinking water, in MCC. Forty eight male Wistar rats weighing 150 g were divided into 4 groups: RH, S.BUT, S.CHL, control (C). Half of the animals received weekly DMH 20 mg/kg subcutaneously for 12 weeks. Necropsy was performed after 6 months. We have determined fecal SCFA content by gas chromatography. Neoplasm was present in 70% of rats treated with DMH. The number of animals with tumors was: RH 4/6, S.BUT 4/6, S.CHL 3/5, C 6/6. Tumor frequency was: RH 1.17 +/- 0.48, S.BUT 1.50 +/- 0.76, S.CHL 1.20 +/- 0.49, C 1.50 +/- 0.22. S.BUT group, treated with DMH, presented a lower butyric acid concentration (p < 0.05) in comparison with other groups. We have no explanation for this finding; gastric absorption of sodium butyrate may be an important factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Influence of VIP on the number of enterochromaffin and mucosal mast cells in the colon of the rat.

The possibility that VIP (Vasoactive intestinal peptide) could influence the enterochromaffin (EC) cell secretion of serotonin (5HT) and the action of VIP on the mast cell population of lamina propria were investigated in Wistar rat colon infused with a short chain fatty acid solution (sodium acetate), during a 1 h period. Under the action of an intravenous injection of synthetic porcine VIP, 14 micrograms/kg/h), the number of EC cells diminished significantly in the cecum and left colon, when compared to non-injected animals, both infused with a sodium acetate solution. At the same time, the number of mucosal mast cells in the crypts and lamina propria decreased significantly in the cecum. The postulate we put forward is that these VIP-induced changes are exerted through the stimulation of 5HT released from EC cells not only under normal physiological conditions but probably also under pathological conditions.

Animals↗
PubMed1992

Effect of ethanol intake on pancreatic exocrine secretion in mice.

Swiss mice were fed conventional lab chow and 10% ethanol or water as drinking fluid for 2 weeks. Pancreatic juice was obtained by cannulation of the bile pancreatic common duct of mice anesthetized with urethane. Isolated pancreatic lobules were also obtained. The flow rate and the amylase output were determined in pure pancreatic juice. The release of amylase was measured in pancreatic lobule preparations. The basal pancreatic juice flow rate and the amylase output were significantly increased by ethanol consumption. The magnitude of the pancreatic juice flow rate and the amylase output responses to increasing doses of bethanechol, a cholinergic agent, was significantly decreased in ethanol-fed mice. The amount of spontaneously released amylase was higher in pancreatic lobule preparations from ethanol-fed animals than that from control mice, and the difference was abolished by addition of atropine to the incubation media. The amylase release rate in response to increasing doses of bethanechol was significantly reduced in lobule preparations from the ethanol-fed group. These data indicate that ethanol intake in mice has a stimulating effect on the spontaneous pancreatic secretion and lends support to the hypothesis that ethanol consumption increases the intrapancreatic cholinergic tone.

Amylases↗
PubMed1990

Effects of intravenous ethanol on basal bile-pancreatic secretion in nonalcoholic and alcohol-fed rats.

In nonalcoholic (NA) and alcohol-fed rats (AF), intravenous-ethanol-induced percentage changes in bile-pancreatic-secretion (BPS) were evaluated, with and without gastric juice diversion (GJD) and with and without BPS duodenal recirculation (DR). Even with GJD, ethanol elicited a slight increase in BPS. These changes were greater in AF animals even when performed without GJD. When intravenous ethanol was given under conditions of GJD and DR, there were marked differences between the NA and AF animals in the ethanol-elicited post-plateau percentage changes of BPS. NA animals evidenced no significant difference from controls. But in the AF rats, ethanol triggered a marked and significant increase of flow, protein concentration, and output that became progressively greater in successive collection periods. It is postulated that without DR, and the resulting lack of negative duodeno-pancreatic reflexes (DPR), there occurs a change in reactivity to intravenous ethanol of the hypothalamic-bulbar nuclei (HBN) and in the mechanisms that modulate the flow of cholinergic impulses through the intrapancreatic ganglia (IPG). The postulated consequence is predominance (slight in NA rats receiving intravenous ethanol, greater in AF rats) in discharge of positive impulses from HBN and flowing unimpeded through the IPG to the "pancreon" units. In the NA animal with DR, ethanol may enhance BPS values, but in the AF rats, impairment of the negative DPR elicited by chronic alcohol intoxication might, after an acute intravenous ethanol injection, favor the discharge of positive impulses from the HBN flowing unimpeded through the IPG. In the AF rats also, ethanol would activate the nonnicotinic receptors of the neurons of the "antral," "duodenal," and "celiac" autonomic brains.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1989

Concanavalin A binding sites in fetal, adult, transitional, and malignant rectosigmoid mucosa.

We studied mucin histochemistry in 25 rectosigmoid adenocarcinomas and in the transitional mucosa adjacent to these tumors using standard techniques for the detection of neutral and acid sialomucins and sulfomucins and the paradoxical concanavalin A (Con A) stain. This histochemical procedure selectively detects residues of mannose in glycoproteins exposed to brief steps of oxidation and reduction. Those techniques were also used to study histologically normal mucosa of specimens with carcinoma, normal rectosigmoid mucosa of patients without inflammatory or neoplastic bowel disease, hyperplastic rectal polyps, and rectosigmoid mucosa of human fetuses. Normal mucosa and hyperplastic polyps mainly contained sulfomucins and did not display Con A binding activity with any of the variants of the stain. In contrast, fetal, transitional, and malignant mucosa predominantly showed sialomucins and although not reactive with the standard Con A sequence, displayed binding activity for the lectin after short oxidative-reductive steps. These results provide further evidence that transitional and malignant mucosa produce markedly abnormal mucins whose histochemical patterns represent a re-emergence of the fetal type found during development. The principles of the paradoxic Con A reaction may be applied to unmask lectin binding activity in apparently unreactive sites.

Adenocarcinoma↗
PubMed1988

Pure pancreatic juice in humans: orange-lemon-juice-induced secretory effects. Comparative analysis with a regular meal, sorbitol, acidified peptone broth and secretin.

The secretory effect elicited by the ingestion of 100 ml of orange-lemon juice (O.-L.J.) was studied on pure pancreatic juice obtained from a catheter placed in the human Wirsung duct at surgery. These changes were compared with those evoked by a regular meal (R.M.), the ingestion of a Sorbitol solution (S.S.), the intragastric infusion of an acidified peptone broth (A.P.B.) and an i.v. single injection of secretin (Boots, 1.0 U/kg). The O.-L.J. induced purer pancreatic secretion response (flow, bicarbonate and enzyme output) than that triggered by the R.M., S.S. and A.P.B. The O.-L.J. evoked peak values, were observed earlier (60 min) than with a R.M. (90 min) ingestion. The 120-min-cumulative values confirmed these findings and disclosed that O.-L.J. elicits a rate of secretion and bicarbonate output closely similar to that of an i.v. secretin injection and amylase response greater than that evoked by this hormone. Thus, O.-L.J. ingestion proved to be an unexpected powerful stimulus of exocrine pancreatic secretion.

Adult↗
PubMed1988

[Post-sectional antral peptic ulcer and antrofundic re-anastomosis in rats (manifestation of a probable antrofundic neuroendocrine center)].

The antrum-fundic section and re-anastomosis (AESR), liberates, in Wistar male rats, genuine antral peptic ulcers. They start within 20 days. They are progressive evolution, penetrating into all gastric walls. Between 7 and 8 months, they involve near organs (spleen, liver, pancreas) and produce a great inflammatory reaction of the peripancreatic ganglions. The antral peptic ulcer is induced if the gastric lesser curvature's nerves are sectioned and a concomitant pyloroplasty is done or not. The gastric hemisection, if anterior or posterior, break out the peptic ulcer only on the same side of the antrum-fundic interruption. In all this situations, except in cases of concomitant pyloroplasty, it is proved a pronounced and significantly increase of the gastric (g/kg), but not pancreatic index. In the AFSR series with nervous section on the lesser curvature and without pyloroplasty, the percentage of antral peptic ulcers in 56%. It is postulated the probably existence, at an antrum-fundic level, of a neuroendocrine center. Its nullification or disturbance by the section and re-anastomosis procedure could generate the antral ulcer and other histologic changes (increase of the "G" cells, hyperplasia of the parietal, ECL and "A like" cells) by one or various hypothetical ways: 1. Direct action, nullifying the normal blocking function of somatostative over the "G" cells and or parietal cells. 2. Disturbing or nullifying the motor pump effect of the gastric antrum, and on this way, enhancing the duodenum-gastric reflux with all know deleterious effects of the bile in the antrum particularly in an acid milieu. 3. Modifying, in the opposite direction, the sensitivity by one hand, of the "G" cells mass and by the other one, of the parietal, ECL and "A like" cells. The depression of the fundic sensitivity will induce the hyperplasia of the "G" cells, the hypersecretion of gastrin and, "a posteriori", all the secretory effects and trophic characteristic of it. 4. Disturbing the prostaglandins secretion, perhaps through a deficit of the nervous innervation, with the resulting epiphenomenon of a cytoprotection deficit mediated through the mucus and bicarbonate production. It is probably that the proposed physiopathogenic mechanism are associated and that the final result, the antral peptic ulcer is the consequence of an increase of the aggressive factors (acid, bile) and a concomitant depression of the defensive factors (cytoprotection), starting normally by the prostaglandins through the mucus and bicarbonate secretion.

Anastomosis, Surgical↗
PubMed1987

Pirenzepine as anti-inflammatory drug in a model of experimental colitis in rat.

Pirenzepine has been widely used for the treatment of gastric and duodenal ulcer. In this work we have proved that this drug could prevent the inflammatory reaction induced in the colon with an intraluminal stimuli as the acetic acid. These data suggest the cholinergic participation in the inflammatory colonic response.

Acetates↗