Basal Acid Research Articles

Phosphate fertilization and bioactivator influences on fractions of organic matter and soil microbial biomass

Soil organic matter is considered a potential source of phosphorus (P) for plants because of biological cycling. Bioactivators are characterized as tools that can help soil microbial activity and the availability of P demanded by plants. The objective of this study was to evaluate the influence of the use of bioactivators and phosphate fertilization on the activity of soil microbial biomass and humified fractions of organic matter. The experimental design was completely randomized in a factorial scheme (6 × 2), with the first factor consisting of six doses of phosphorus applied to the soil (0, 30, 60, 90, 120, and 150 kg ha-1 of P2O5), using triple superphosphate as the source, and the second factor being the presence or absence of soil and plant bioactivator application, with four replications. The evaluated characteristics were soil microbial biomass carbon (SMBC), soil basal respiration (SBR), microbial biomass nitrogen (MBN), metabolic quotient (qCO2), microbial quotient (qmic), total organic carbon (TOC), fulvic acid fraction carbon (FAC), humic acid fraction carbon (HAC), and humin fraction carbon (HUMC). The use of soil and plant bioactivators and mineral phosphate fertilizer promoted changes in soil microbial activity. Increasing doses of phosphate fertilization promoted a reduction in the carbon characteristics of microbial biomass and basal soil respiration in the presence or absence of soil and plant bioactivators. Moreover, the use of bioactivator promoted higher averages for soil microbial biomass carbon, soil basal respiration, metabolic quotient, humic acid and humin and reduced the levels of microbial quotient, total organic carbon and fulvic acid.

P92 Effect of increasing level of calcium on basal ileal endogenous amino acid losses in cannulated pigs fed nitrogen-free diets

P92 Effect of increasing level of calcium on basal ileal endogenous amino acid losses in cannulated pigs fed nitrogen-free diets

P104. Basal endogenous amino acid losses in the digestive tract are determined by experimental conditions, a meta-analysis

P104. Basal endogenous amino acid losses in the digestive tract are determined by experimental conditions, a meta-analysis

Grape Pomace Ingestion by Dry Cows Does Not Affect the Colostrum Nutrient and Fatty Acid Composition.

Simple SummaryThe introduction of alternative feedstuff such as grape pomace into the diets of dry cows could decrease the cereal needs in ruminant feeding systems and could modify the composition of colostrum. Grape pomace is a by-product of the wine industry. It contains polyphenols and fatty acids, which have the potential to improve the animal product quality. The nutritional quality of colostrum and the quality of colostral fat is affected by dry cow nutrition in the late stages of pregnancy. This study determined the potential of grape pomace feeding to increase colostral protein, which, according to the literature, is connected with the concentration of immunoglobulin G, better passive immunisation, and the health of calves. The addition of grape pomace was determined to have no effect on colostral nutrient and fatty acid concentrations. Thus, grape pomace can be used as a nutrient source for dry cows.The utilisation of different by-products from the food industry as nutrient sources for farm animals is both possible and beneficial. Grape pomace is a by-product that contains polyphenols and fatty acids, both of which have the potential to improve the nutritional quality of cow colostrum. This study aimed to explore how the addition of grape pomace to the diet of dry cows affects the concentration of nutrients and fatty acids of colostrum. Sixteen Slovak spotted cows in late pregnancy were used in this study. From the seventh day before expected calving to the day of calving, cows in the grape pomace group received a diet supplemented with dried grape pomace, at 0.116 kg/cow/day. Colostrum samples were analysed for basal nutrients and fatty acid concentrations. Between the control and experimental groups, the nutrient and fatty acid concentrations of all the colostrum samples did not show significant differences. The nutrient levels in the colostrum from both groups of cows were typical, as related to the time from calving. The addition of the grape pomace into the diet of dry cows had no effect on nutrient concentrations and the fatty acid composition of the colostrum. The somatic cell score of the colostrum sampled at the 12th hour after calving (4.2 versus 2.6) was positively affected by grape pomace addition. The results of this study revealed that grape pomace (fed in an amount of 0.116 kg/cow/day) had no positive or negative effect on the base nutrients and fatty acids of cow colostrum, and, therefore, grape pomace can be used as a nutrient source for dry cows in small amounts.

Sham Feeding Induced Gastric Acid Secretion in Patients with Caustic Induced Esophageal Stricture.

Caustic ingestion can lead to structural changes in the upper gastro-intestinal tract. However, there is limited data on the effect of caustic ingestion on gastric secretion. This study was planned to determine changes in gastric acid output after sham feeding in patients with caustic induced esophageal stricture and to compare it with healthy controls. It was a prospective study done at tertiary care center in North India. Consecutive patients with caustic induced esophageal stricture were evaluated for the study. Gastric secretory function was estimated in the basal state and after modified sham feeding. These results were compared withage-matched controls. The mean age of the included patients (n = 18) was 30.11 ± 9.19years and 13 patients were male. 16 (88%) patients had history of acid ingestion. Patients with caustic sequelae had significantly lower basal and stimulated acid secretion compared to controls (n = 10) (5.84 ± 2.44mmol/hr; p < 0.01 and 17.16 ± 7.53mmol/hr; p < 0.01; respectively). Patients with lower esophageal stricture (n = 8) had significantly lower increase in acid output compared to patients with stricture elsewhere in esophagus (0.20 ± 0.3 vs. 2.31 ± 1.74mmol/hr, p < 0.01). Patients with lower esophageal involvement had significantly lower stimulated acid secretion and increase in acid secretion compared to controls (4.74 ± 4.67 vs. 17.16 ± 7.53mmol/hr; p < 0.01 and 20 ± 0.3 vs. 2.09 ± 0.88mmol/hr; p < 0.01; respectively).

Dihydroquercetin (taxifolin) attenuates dexamethasone activity on prostaglandin E-2 but potentiates thromboxane-A2 action in gastric acid secretion in wistar rats

The activity of dexamethasone and taxifolin {(2R, 3R)-2-(3, 4-Dihydroxyphenyl)-3,5,7-trihydroxy-2,3-dihydrochromen-4-one}supplementation on prostaglandin E2 and thromboxane A2 in gastric acid secretion and anti-ulcer was studied. Twenty male Wistar rats (180g-200g body weight) were used. The rats were randomly selected into four groups containing 5 rats each. Group 1 was the control group fed on normal rat feed. Group 2 received 3mg/kg of Dexamethasone (intraperitoneally) at one day interval. Group 3 received 3mg/kg of Dex. intraperitoneally and 1mg/kg body weight of taxifolin orally while group 4 received 1mg/kg body weight of taxifolin. At the end of 6 weeks, basal and peak gastric acid output was measured by continuous perfusion of rats stomach under anaesthesia with normal saline at the rate of 1ml/min. Gastric acid, mucus secretion, ulcer index, PGE-2 and thromboxane A2 activity were determined according to standard procedures. Results showed a significantly (p&lt;.05) decreased prostaglandin and mucus secretion level and a raised thromboxane concentrations and gastric acid output in dexamethasone administration. Taxifolin significantly (p&lt;.05) lowered thromboxane A2 concentration in Dex treatment while increasing the prostaglandin E2 level. We conclude that Taxifolin decreases dexamethasone- induced gastric acid secretion, increases prostaglandin activity but reduces thromboxane concentration.

181 Effects of Aspergillus oryzae prebiotic on energy and nutrient digestibility of growing pigs

Abstract The objective of this study was to determine the effects of an Aspergillus oryzae prebiotic (AOP, Amaferm®) on nutrient digestibility in growing pigs fed high fiber diets. Eighteen growing barrows (initial BW = 50.60 ± 4.90 kg) were surgically equipped with a T-cannula at the distal ileum. Three diets were formulated by including 29.65% corn-distillers dried grains with solubles (DDGS), 36.65% rice bran (RB) or 24.59% wheat middlings (WM) in corn and soybean meal-based diets to meet nutrient requirements for 50 to 75 kg growing pigs. Three additional diets were formulated by supplementing 0.05% AOP at the expense of corn in DDGS (DDGS + AOP), RB (RB + AOP), and wheat middlings (WM + AOP) diets. Pigs were allotted randomly to a triplicated 6 × 2 Youden square design with 6 diets and 2 successive periods. Feces and ileal digesta were collected for 2 d after a 21 d adaptation period, and nutrient content was analyzed to calculate apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID). Standardized ileal digestibility (SID) of amino acids was calculated by correcting AID with basal endogenous amino acid losses determined from the same set of pigs. Supplementation of 0.05% AOP increased (P &amp;lt; 0.05) ATTD of DM, GE, CP, NDF, and ash in DDGS, RB, and WM diets. Diet DE was 35 kcal/kg greater (P &amp;lt; 0.05) in pigs fed AOP supplemented diets compared with those fed diets without AOP. Pigs fed DDGS+AOP diet had greater (P &amp;lt; 0.05) AID of ether extract compared to those fed DDGS diet. However, supplementation of AOP did not (P &amp;gt; 0.05) affect AID of GE, DM, CP, NDF, ash or SID of amino acids. In conclusion, supplementation of AOP in high fiber diets containing DDGS, RB, or WM increased total tract energy value and nutrient digestibility.

Regression-Derived Ileal Endogenous Amino Acid Losses in Broiler Chickens and Cannulated Pigs Fed Corn Fiber, Wheat Bran, and Pectin.

Simple SummaryFor animal agriculture to be environmentally sustainable, nitrogen excretion must be reduced. This means diet must be formulated to closely meet the requirements of the animal. Accounting for basal endogenous amino acid (EAA) losses during diet formulation helps in formulating diets that closely match amino acid requirements. These studies examined the effect of three or two different ingredient types on basal losses of amino acids in broiler chickens or pigs, respectively. Corn fiber resulted in higher ileal EAA losses compared with wheat bran in broiler chickens. With the exception of His, Leu, and Tyr, there was no difference in basal ileal EAA losses between corn fiber and pectin in cannulated growing pigs. These studies show that in addition to fiber effects, dietary nitrogen sources could have a different effect on basal ileal EAA losses.The objective of these studies was to determine the effect corn fiber (CF), wheat bran (WB) and pectin (PEC) on basal ileal endogenous amino acid (EAA) losses in broiler chickens (Exp. 1) and cannulated pigs (Exp. 2) using the regression method. Semi-purified diets containing 100 g/kg of CF, WB, or PEC (broiler chickens) and CF or PEC (pigs) were fed to replicate cages consisting of eight birds per cage of 21-d-old broiler chickens and six replicates of pigs consisting of one pig per pen. Ileal endogenous His, Glu, and Pro losses were higher (p < 0.05) for CF and WB compared with birds fed diets containing PEC. Contrasts between CF and WB showed higher (p < 0.05) ileal endogenous nitrogen, total amino acid, His, Ile, Met, Glu, Pro, and Tyr losses in birds fed the CF diets (Exp. 1). Contrasts of EAA losses between birds fed the WB and PEC diets showed higher (p < 0.05) losses for His, Glu, and Pro. In the cannulated pigs, CF resulted in higher (p < 0.05) ileal endogenous His, Leu, and Tyr losses. In summary, CF induced higher ileal EAA losses in broiler chickens and cannulated pigs.

STUDY OF ANTISECRETORY ACTIVITY OF DINITRATE 2-PHENYL-9-DIETHYLAMINOETHYLimidazo[1,2-A] BENZIMIDAZOLE BY METHOD OF CONTINUOUS PERFUSION OF RATS’ STOMACHS

Nowadays, effective pharmacotherapy of acid-dependent gastrointestinal diseases remains an urgent problem of modern gastroenterology. In this regard, the search for new drugs with a pronounced antisecretory activity still continues; their aim is to keep the control over the acid production safe and effective.The aimof this study was an experimental study of the antisecretory activity of the substance and the finished dosage form (FDF) of dinitrate 2-phenyl-9-diethylaminoethylimidazo[1,2-a]benzimidazole.Materials and Methods.The study of antisecretory activity was performed by method of a continuous perfusion of rats’ stomachs. The studied substance was administered at the doses of 3, 10 and 30 mg/kg, and the FDF – at the doses of 13 and 26 mg/kg. The substance of Ranitidine (Sigma Аldrich, USA) was used as a reference object in the study of the antisecretory activity of the substance under study, and Ranitidine (Hemofarm A.D., Serbia) was used as a reference drug in the study of the FDF. In order to determine the stimulated secretion immediately before collecting the samples of the perfusate, histamine was administered subcutaneously at the dose of 5 mg/kg. The content of hydrochloric acid in the perfusate was determined by titration of a 0.01 M sodium hydroxide solution. The acidity value was determined in terms of the debit-hour of hydrochloric acid.Results and discussion.The obtained experimental data showed that the studied substance at the dose of 30 mg/kg decreased the basal hydrochloric acid secretion by 54%, which significantly exceeded the antisecretory effect of Ranitidine by 1.8 times. The FDF at the dose of 26 mg/kg, statistically reliable relative to the control and the group treated with Ranitidine, decreased the basal secretion of gastric juice by 33%. The substance at the dose of 30 mg/kg reliably suppressed the stimulated secretion of hydrochloric acid by 80%, while Ranitidine did it by 56%. The FDF at the dose of 26 mg/kg decreased the histamine-stimulated secretion by 66%, and Ranitidine did it by 52%, which was statistically reliable.Сonclusions.The studied substance and its dosage form are more effective in suppressing basal activities and exceed the anisecretory activity of H2 -histamine antagonists of Ranitidine under the conditions of the secretion stimulated by histamine.

1945-P: The Mitochondrial Protein DRP1 Is Required for Endogenous Fatty Acid Oxidation

Introduction: Mitochondria are organelles that routinely undergo fission and fusion in a process known as mitochondrial dynamics. Increased mitochondrial fission is implicated in the pathogenesis of obesity, type 2 diabetes, and metabolic disease. DRP1 has been identified as a key regulator of mitochondrial fission. We and others have demonstrated that loss of DRP1 is associated with improvements in glucose homeostasis, however, the role of DRP1 in mitochondrial fatty acid oxidation is unknown. The purpose of this study was to measure endogenous fatty acid oxidation in DRP1-deficient skeletal muscle cells. Methods: C2C12 myoblasts were stably transfected with DRP1 shRNA (KO) or a scrambled control (CT). Myoblasts were then cultured in a substrate-limited DMEM (0.5mM glucose, 0.5mM carnitine, 1mM glutamine, and 1% FBS) overnight. 15 minutes prior to assay, etomoxir was added to inhibit endogenous fatty acid oxidation (FAO). Cells were then challenged with either bovine serum albumin (BSA) or palmitate (PA) and assessed for mitochondrial function using whole cell respirometry (Agilent XFe24). Additionally, cells were treated with 14C-labeled PA in the absence and presence of increasing glucose concentrations to assess metabolic flexibility and fatty acid oxidation. Results: Basal whole cell (P&amp;lt;0.05) and endogenous fatty acid (P&amp;lt;0.05) oxygen consumption were reduced in KO cells relative to CT (P&amp;lt;0.05). Furthermore, ATP linked fatty acid oxidation was blunted in the KO cells (P&amp;lt;0.05). Conclusion: Here, we show that DRP1 is required for FAO. After inhibition of FAO with etomoxir, basal and ATP-linked respiration were ablated in DRP1-deficient cells. These findings suggest that loss of DRP1 ablates the ability of cells to use endogenous fatty acids as substrate when carbohydrate is not available. These data suggest that impaired lipid metabolism, rather than inhibition of mitochondrial fission, may explain improvements in glucose homeostasis with the loss of DRP1. Disclosure W.T. King: None. C.L. Axelrod: None. G. Davuluri: None. R.C. Noland: None. J.P. Kirwan: None. Funding National Institutes of Health (R01DK108089, U54GM104940, R01DK103860)

Phytoremediation affects microbial development on a limestone quarry

ABSTRACTPhytoremediation was used to regenerate a limestone quarry area. Plant growth mixed medium added over the quarry surface, consisting of a mixture of pyrolusite byproducts, natural soil, sand, and rice husk. Three different plant species: pine, cypress, and broom were planted at 9 randomized plots in order to assess the effects of vegetation on the microbial development, which was measured for the following 3 years. Substrate samples were analyzed for organic carbon content (Corg), microbial biomass (Cmic), basal CO2 respiration activity (BR), alkaline phosphatase (ALP), and acid phosphatase activities at each plant specie and year. Furthermore, the ratio Cmic/Corg, the metabolic quotient (qCO2), and the C mineralization quotient (qM) were determined. The highest survival rates occurred for broom (93.52%), followed by cypress and pine (82.41%) at the final year, while the content of Cmic, BR, and ALP was increased significantly under plants (pine, cypress, and broom) compared with control. Cmic content and BR was plant dependent. Cypress sites had the highest values of Cmic (214.9 μgCg−1) and BR (112.8 μgCO2-Cg−1d−1) at the 3rd year. The plant root environment clearly enhances and regulates the microbial community, in correspondence to the species used. Below ground enhanced activity could fulfill the scope of phytoremediation strategies.

Gastric antiulcer, antisecretory and cytoprotective properties of celery (Apium graveolens) in rats

Celery seed is generally regarded as safe for human consumption as a spice, natural seasoning and plant extract/essential oil. 500 grams of the shade dried aerial parts of celery was coarse powdered and macerated in 3 liters of 96% ethanol for 72 hours using percolation method. Wistar albino rats were used. Celery extract produced a dose-dependent significant protection against the ulcerogenic effect induced by indomethacin. In the ethanol and strong alkali-induced ulcer protocol, it was observed that the treatment with ethanolic extract of celery (250 and 500 mg/kg) significantly reduced the lesion index. A highly significant reduction of ulceration in rats' stomach and intraluminal bleeding was recorded after celery extract pretreatment of the dose of 500 mg./kg orally. In the gastric secretion determination model, using ligated pylorus for 6h, the treatment with celery extract (250 and 500 mg/kg i.p.), reduced the volume of the basal gastric secretion, titratable acidity and ulceration significantly in comparison with control group. The results show that ethanol extract of celery displays gastroprotective activity, as demonstrated by its significant inhibition of the formation of ulcers induced by different experimental models and its ability to decrease basal gastric acid secretion. This gastric antiulcer capacity of celery extract could be related to its antioxidant properties, resulting in reduction of the lipid peroxidation and elevation of the NP-SH contents, besides improving mucus coat of the stomach. Therefore, we suggest that due to its antioxidative effects, it may be useful in the prevention of gastric disorders.

Sa1725 FFA2 Activation Suppresses Basal and Stimulated Gastric Acid Secretion via 5-HT3 Receptor Activation in Rats

Sa1725 FFA2 Activation Suppresses Basal and Stimulated Gastric Acid Secretion via 5-HT3 Receptor Activation in Rats

The gastric mucosa 25 years after proximal gastric vagotomy

Objective. Vagotomy causes inhibition of basal and post-prandial acid secretion in humans, but the knowledge about the trophic effect of the vagal nerves is limited. Vagotomy is known to induce hypergastrinemia and we aimed to study the long-term effects of proximal gastric vagotomy (PGV) on the oxyntic mucosa and the enterochromaffin-like (ECL) cell density in particular. Material and methods. Eleven patients operated with PGV because of duodenal ulcer and age- and sex-matched controls were examined 26 to 29 years postoperatively by gastroscopy with biopsies from the antrum and oxyntic mucosa. Neuroendocrine cell volume densities were calculated after immunohistochemical labeling of gastrin, the general neuroendocrine cell marker chromogranin A (CgA) and the ECL cell marker vesicular monoamine transporter 2 (VMAT2). Gastritis was graded and Helicobacter pylori (H. pylori) status was determined by polymerase chain reaction of gastric biopsies. Fasting serum gastrin and CgA were measured. Results. Serum gastrin was higher in the PGV group compared to controls (median 21.0 [interquartile range (IQR) = 22.0] pmol/L vs 13.0 [IQR = 4.0] pmol/L, p = 0.04). However, there was neither a significant difference in serum CgA or in CgA (neuroendocrine) nor VMAT2 (ECL cell) immunoreactive cell volume density in the oxyntic mucosa. There was significantly more inflammation and atrophy in H. pylori-positive patients, but PGV did not influence the grade of gastritis. Conclusion. Despite higher serum gastrin concentrations, patients operated with PGV did not have higher ECL cell mass or serum CgA. Vagotomy may prevent the development of ECL cell hyperplasia caused by a moderate hypergastrinemia.

Sa2024 Involvement of Gastric Secretion and Primary Capsaicin-Sensitive Afferent Nerves in the Gastroprotection Induced by Hydrogen Sulfide in Rat Stomach

Hydrogen sulfide (H2S) modulates a number of physiological actions including vasodilatation, inhibition of oxidant stress and apoptosis. H2S which is formed in gastric epithelium by the activity of two enzymes cysthationine γ-lyase (CSE) and cystathionine β-synthetase (CBS) has been shown to protect the gastric mucosa from ethanol-induced gastric lesions but whether its efficacy against acid-dependent stress-induced damage has been little studied. It also remains unknown how the expression of CSE and CBS contribute to the mucosal damage induced by stress in the presence or absence of H2S. We studied the effect of NaHS, a H2S-donor and L-cysteine, a H2S precursor on 1) gastric acid secretion in rats equipped with chronic gastric fistulas (GF) and water immersion restraint stress (WRS)-induced gastric lesions with intact and capsaicin-denervated sensory nerves (large dose 125 mg/kg s.c for 3 days). Rats were pretreated 30 min before the WRS with A) NaHS (5 mg/kg i.g); B) Lcysteine (10 mg/kg i.g.) with or without the combination with inhibitors of CSE activity, beta-cyano-L-alanine (BCA, 50 mg/kg i.g.) and D,L-propargylglycine (PAG 15 80 mg/kg i.g.). The number of gastric lesions was measured by planimetry, the gastric blood flow (GBF) by H2-gas clearance technique and the mRNA expression of CSE, CBS, HIF-1 α and antioxidizing enzymes SOD and GPx was assessed by RT-PCR and Western Blot. NaHS (120 mg/kg) and cysteine (5-40 mg/kg) dose-dependently inhibited basal and histaminestimulated gastric acid secretion in GF rats. Exposure to WRS caused mucosal hemorrhagic lesions accompanied by the fall in GBF and upregulation of mRNA expression of CSE and CBS. Pretreatment with NaHS and L-cysteine significantly reduced WRS-induced gastric damage and significantly raised GBF and these effects were completely lost in animals with capsaicin denervation. BCA and PAG which dose-dependently augmented the number of WRS lesions, reversed the NaHS and L-cysteine-induced protection and hyperemia against WRS-induced gastric damage. Upregulation of mRNA expression for HIF-1 α mRNA, CSE and CBS in the gastric mucosa exposed to WRS was diminished by NaHS and L-cysteine and these effects were further enhanced in capsaicin-denervated rats treated with NaHS and L-cysteine. The increased expression of SOD and GPx mRNA was observed in NaHSand L-cysteine-pretreated rats but not in those with capsaicin-denervation. We conclude that: 1) an increase in the expression of CSE and CBS, key enzymes in H2S biosynthesis, could compensate for the stress-induced impairment of gastric mucosal defense; 2) antisecretory activity of H2S donors contributes to the attenuation of acid-dependent injury caused by WRS, and 3) sensory mediators and antioxidizing enzymes SOD and GPx play an important role in H2S-induced gastroprotection against WRS-induced ulcerogenesis.

Early metabolic defects in Arab subjects with strong family history of Type 2 diabetes.

It is widely accepted that the genetic make-up of the subject plays a pivotal role in the development of insulin resistance and β cell failure. The objective of this study was to examine whether the same or distinct genetic backgrounds contribute to the development of insulin resistance and β cell failure. We examined insulin sensitivity and β cell function in lean normal glucose tolerance subjects from 3 multigeneration Arab families. Families 1 and 2 had strong history of Type 2 diabetes (T2DM), while no member of family 3 had T2DM. Subjects in family 1 manifested increased basal plasma free fatty acid (FFA) concentration and impaired suppression of plasma FFA during the OGTT compared to subjects in family 3. Subjects in family 2 had comparable fasting plasma FFA and suppression of plasma FFA during the OGTT to family 3. Both the absolute plasma glucose concentrations, and incremental area under the plasma glucose curve (ΔG0-120) during the OGTT were comparable in subjects of families 1 and 2, and were decreased in subjects of family 3. Whole body and muscle insulin sensitivity were comparable in subjects from families 2 and 3, and both were significantly decreased in subjects of family 1. Beta cell function was comparable in subjects of families 1 and 3 and was significantly decreased in subjects of family 2. These results demonstrate that distinct genetic background contributes to the development of insulin resistance and β cell dysfunction in Arab individuals.

Gastric Ulceration in Diabetes Mellitus: Protective Role of Vitamin C

The effect of vitamin C administration on gastric acid secretion and ulcer in diabetic rats was studied. Vitamin C (200 mg/kg b.w.) was administered to both streptozotocin-induced diabetic and control groups orally for 28 days. Gastric acid secretion was measured and ulcer was induced using ethanol. Histological changes were observed in the stomach. Basal and stimulated acid secretion in diabetic control rat was significantly (P < 0.01) decreased when compared to vitamin C-treated diabetic group and control. Administration of vitamin C significantly (P < 0.05) increased the histamine-stimulated gastric acid secretion in diabetics than control while reduction in gastric secretion by ranitidine was similar compared with control. Vitamin C treatment significantly (P < 0.05) reduced ulcer index in diabetic group and increased mucus weight when compared with diabetic group which was also confirmed with photomicrographs. The mean body weight of diabetic rats treated with vitamin C was comparable to the control. The blood glucose level was significantly (P < 0.01) reduced in diabetic group given vitamin C (8.9 ± 1.8 mMol/L) compared to the diabetic control (32.2 ± 2.1 g). It is concluded that vitamin C is beneficial in improving gastric acid secretion and protects against ulceration in streptozotocin-induced diabetes mellitus in rats due to its antioxidant potential.

Gastrin-Deficient Mice Have Disturbed Hematopoiesis in Response to Iron Deficiency

Gastrins are peptide hormones important for gastric acid secretion and growth of the gastrointestinal mucosa. We have previously demonstrated that ferric ions bind to gastrins, that the gastrin-ferric ion complex interacts with the iron transport protein transferrin in vitro, and that circulating gastrin concentrations positively correlate with transferrin saturation in vivo. Here we report the effect of long-term dietary iron modification on gastrin-deficient (Gas(-/-)) and hypergastrinemic cholecystokinin receptor 2-deficient (Cck2r(-/-)) mice, both of which have reduced basal gastric acid secretion. Iron homeostasis in both strains appeared normal unless the animals were challenged by iron deficiency. When fed an iron-deficient diet, Gas(-/-) mice, but not Cck2r(-/-) mice, developed severe anemia. In iron-deficient Gas(-/-) mice, massive splenomegaly was also apparent with an increased number of splenic megakaryocytes accompanied by thrombocytosis. The expression of the mRNA encoding the iron-regulatory peptide hepcidin, Hamp, was down-regulated in both Cck2r(-/-) and Gas(-/-) mice on a low-iron diet, but, interestingly, the reduction was greater in Cck2r(-/-) mice and smaller in Gas(-/-) mice than in the corresponding wild-type strains. These data suggest that gastrins play an important direct role, unrelated to their ability to stimulate acid secretion, in hematopoiesis under conditions of iron deficiency.

Effects of tamoxifen on striatal dopamine and 5-hydroxytryptamine release in freely moving male rats: an in-vivo microdialysis investigation.

Recent studies indicating interaction of oestrogens with central cholinergic, dopaminergic and 5-HTergic systems have led to the assumption of a protective role of oestrogens in certain neurodegenerative disorders. The non-steroidal drug tamoxifen, a mixed oestrogen agonist-antagonist, has been shown to modulate central nervous system functions in the corpus striatum. In this study we used a microdialysis technique to examine the effects of tamoxifen upon the striatal dopaminergic and 5-HTergic systems in intact freely moving male rats. The extracellular levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were measured after intraperitoneal administration of either the control or tamoxifen, and were compared with their corresponding baseline levels. Significant 25-35% increases in the baseline levels of dopamine and 3,4-dihydroxyphenylacetic acid were observed after the highest doses of tamoxifen (1.5 mg kg(-1) and 30 mg kg(-1), respectively), whereas the lowest dose of tamoxifen (0.3 mg kg(-1)) elevated dopamine and 3,4-dihydroxyphenylacetic acid levels by a detectable 15% of the basal. In addition, the ratio of 3,4-dihydroxyphenylacetic acid-to-dopamine remained unchanged in comparison with that of the pretreatment levels. Whereas no change in the striatal 5-hydroxyindoleacetic acid concentrations was seen with the lowest and highest dose regimen, the intermediate dose elicited a moderate increase (20%) in basal 5-hydroxyindoleacetic acid levels. The pharmacological relevance of the effects of tamoxifen on the dopaminergic and 5-HTergic systems, as a prelude to the development of non-steroidal oestrogenic compounds in reducing the risk of neurodegenerative disorders such as Alzheimer's disease, is discussed.

Adaptation of the Secretion of Gastric Acid and Gastric Inhibitory Peptide in Response to Propylthiouracil

The purpose of this study was designed to investigate the effects of the intravenous (IV) infusion of propylthiouracil (PTU) on basal and pentagastrin-stimulated gastric acid secretion (GAS), as well as plasma concentrations of gastric inhibitory polypeptide (GIP), and calcium (Ca(superscript 2+)). The polyethylene (PE) tubes were inserted into the esophagus, pylorus, right femoral and jugular veins as luminal and vascular exits respectively in adult male rats. Basal GAS was collected for 45 min before IV infusion of alkaline saline (2 ml/h, control group) or PTU (20 mg/ml/ 300 g BW, experimental group) for 45 min. Infusion of pentagastrin (8 μg/ml/300 g BW) was added for 90 min following infusion of alkaline saline or PTU for an additional 45 min. IV infusion of PTU increased the concentrations of plasma thyroid-stimulating hormone (TSH) and GIP but decreased the level of plasma Ca(superscript 2+) in male rats. Neither the basal nor the pentagastrin-evoked levels of gastric acid secretion were altered by the IV infusion of PTU. These results suggested that the unchanged gastric acid secretion in male rats after IV administration of PTU was at least in part due to an adaption of gastric acid secretion to PTU caused by increased release of GIP and decreased level of plasma calcium.