Meal In Dogs Research Articles

Digestibility of insect meals for dogs and their effects on blood parameters, faecal characteristics, volatile fatty acids, and gut microbiota

To evaluate the effects of the inclusion of three insect meals in dogs’ diets (Madagascar cockroach, MC; cinerea cockroach, CC; and superworm, SW) at two different levels (7.5 and 15%) on nutrients digestibility, blood parameters, faecal characteristics, volatile fatty acids, and gut microbiota, a digestibility trial was performed in a 3×2 factorial scheme in Latin square design 6×6. Experimental diets consisted of insect meals replacing the reference diet (dry and moist commercial feeds) on each of the two levels. Apparent metabolised energy of dry matter (AMEDM) was higher for dogs fed with SW than MC meal in both inclusion levels and, with CC meal at 7.5% of inclusion. The digestibility for dry and organic matter and protein was higher for dogs fed with SW than for MC meals. The faecal pH was lower for the dogs fed with CC than for the MC meal. Butyrate was higher for dogs fed with CC than MC and SW meals. Phenol was higher for dogs fed with MC than SW meal. The relative abundance of the phyla Proteobacteria and the genusSutterella were higher at 7.5% of inclusion than 15%. Dogs fed with SW meal had a greater abundance ofPrevotella,Faecalibacterium, and an unidentified genus in the family Ruminococcaceae than dogs fed with MC meal. The abundance ofAllobaculum was higher for dogs fed with SW meal than CC meal. Even though all the insect meals evaluated can be included in adult dogs’ diets, the superworm meal appears as a highly digestible ingredient for dogs with lower negative impacts on intestine fermentative products and microbiota profile.

Preparation and the assessed efficacy of oral baits for the vaccination of free-roaming dogs against rabies.

Background and Aim:Rabies is considered a highly fatal zoonotic disease and many deaths in humans have been associated with dog bites. This study was designed to prepare an oral anti-rabies vaccine in the form of baits to eliminate the disease in free-roaming dogs and subsequently protect humans from dog bites.Materials and Methods:The Evelyn Rokintniki Abelseth (ERA) rabies virus strain was propagated in baby hamster kidney cell cultures and adjusted to the recommended dose for application. Four forms of oral baits were employed with the rabies vaccine, which was evaluated for safety, acceptability, and potency in different dog groups. Enzyme-Linked Immunosorbent Assay (ELISA) and the serum neutralization test (SNT) were used to determine the protective rabies antibody titer in the sera of vaccinated dogs.Results:According to the results, a dose of 3 mL of the ERA strain, containing a viral titer of 107.6 TCID50/mL, induced a mean antibody titer of 25.6 by SNT, and the PI% was 75.7 by Block ELISA, providing a protective level of the rabies antibody in 100% of vaccinated dogs. All used baits were found to be safe, inducing no abnormal general post-vaccination signs (the signs are limited to mild fever, mild loss of appetite, and mild-to-moderate loss of energy for 24-36 h after vaccination).Conclusion:It was found that most of the accepted and highly potent bait types consisted of a mixture of wheat flour, vegetable oil, sodium alginate, corn starch, meat meal, cellulose gum, and water. This dog meal was covered with bran and edible wax to seal the bait cavity after inserting the vaccine sachet. This bait was able to induce a protective level of rabies antibodies in 100% of vaccinated dogs after receiving one bait/dog. Hence, such a bait could be recommended for use in the protection of free-roaming dogs and the elimination of the disease.

Nutritional Evaluation of Pulses and Soybean Meal in Dogs

Six adult Labrador dogs were used in this experiment to evaluate total tract apparent nutrient digestibility and energy values of some protein feedstuffs. Seven digestibility trials were conducted. The 30% of basal diet was replaced with test ingredient which included one conventional feed ingredient i.e. soybean (Glycine max) meal (SBM) and five pulses (black-eyed pea or roongi (Vigna unguiculata), red lentil or masoor (Lens culinaris) dhuli, moong (Vigna radiata) dhuli, split bengal gram or chana (Cicer arietinum) dal and split black gram or urad (Vigna mungo) dhuli dal). The prepared mash diets were cooked and then fed to each dog as per their body weight and nutrient requirement. The difference/substitution method was used to estimate total tract apparent nutrient digestibility and energy values of these six protein ingredients. The DM, OM, CP, EE digestibility of masoor dhuli dal was significantly (P<0.05) higher than all other protein ingredients. The digestibility of DM, CP, EE, CF and DE in SBM was similar to that in masoor dhuli dal, however, ME value of masoor dhuli dal was higher (P<0.05) than that of SBM. The ME value of chana dal and mung dhuli dal was similar to that of SBM. It was concluded that masoor dhuli dal could be used as an effective protein source in dog diets.

Suspected Isolated Pancreatic Enzyme Deficiencies in Dogs

Suspected Isolated Pancreatic Enzyme Deficiencies in Dogs

Cystic Echinococcosis in Sardinia: Farmers’ knowledge and dog infection in sheep farms

Cystic Echinococcosis (CE) is one of the most widespread parasitic diseases in Sardinia, the second largest Mediterranean island where almost 3,558,000 milk sheep were raised extensively. The aim of this survey was to evaluate the level of farmers’ knowledge on CE transmission, focusing on the role of human to facilitate the persistence of this zoonosis in Sardinia after 14 years after the last campaign against CE. The other goal of the survey is to update on presence of Echinococcus granulosus in its definitive hosts through three ELISA coproantigen tests. An interview was carried out with 172 farmers. The questionnaire was designed to include possible factors associated with the transmission of Echinococcosis: ownership and number of dogs, the use of anthelmintic drugs against dog cestode, frequency of anthelmintic treatment in dogs, home slaughtering and offal disposal. Individual faecal samples were retrieved from 300 dogs, and after a preliminary macroscopic examination to discover adult worms and/or proglottids, was submitted to copromicroscopic examination. Coproantigens were then extracted according to the protocol described by Allan et al. (1992), and subsequently stored at −20°C until use.Faecal soluble antigens from E. granulosus were detected using three different ELISA coproantigen assays: (a) the commercially produced Chekit Echinotest (Bommeli, Bern, CH) based on polyclonal antibodies against adult excretory/secretory (E/S) antigens; (b) a sandwich ELISA that uses rabbit polyclonal antibodies against adult E/S antigens and biotinylated monoclonal antibody EmA9 produced against adult Echinococcus multilocularis somatic extract (Malgor et al., 1997); and (c) a sandwich assay that uses monoclonal antibody EgC3 produced by immunization with adult E. granulosus E/S products (Casaravilla et al., 2005).Questionnaire results reveal that on all farms home-slaughtering was done, and offal was used as dog meal raw (17%) or after boiling (37%), discarded in the trash (23%), or buried superficially (15%). Most farmers (69%) declared to deworm their dogs, but only 10% used cestodicidal drugs. The coprological survey of 300 farm dogs using sedimentation, flotation and three different coproantigen (CA) ELISAs resulted in a faecal prevalence of 8.3% for taeniid eggs, while the CA tests gave prevalences of 3% (Chekit Echinotest, Bommeli), 6% (EmA9 sandwich ELISA) and 10% (EgC3 sandwich ELISA). Our results show that this is not only an educational problem, but also an economic one, stressing the need that future control plans should follow an integrative approach including veterinary and medical services, farmers, breeders’ associations and the Government.

Orally administered kappa but not mu opiate agonists enhance gastric emptying of a solid canned food meal in dogs.

The effects of oral administration of selective mu (D-Ala2, N-Me-p-nitro-Phe4, Gly5-ol-DAGO, morphine) and/or kappa (3,4 dichloro-N-methyl N [2-(1. fyrrolidinyl) cyclohexyl]-benzene acetamide-U-50488, tifluadom) or mixed agonist (N-desmethyltrimebutine) opioid on gastric emptying have been evaluated using a radiolabelled [57Co] canned food meal in dogs fitted with gastric cannulas. In control conditions (placebo) the percentage of solids emptied 1 h after feeding was 27.3 +/- 4.1%. When given orally at doses of 0.01 to 0.5 mg kg-1, U-50488 increased significantly (P less than 0.05) by 29.1 to 60.8% in a dose-related manner (r-0.94, P less than 0.01) the amount of gastric emptying of the meal in 1 h. This effect was reproduced by oral administration of tifluadom (0.01 to 0.1 mg kg-1) and by N-desmethyltrimebutine (0.1 to 1 mg kg-1). In contrast, the gastric emptying was unaffected by DAGO and morphine at low doses (0.01 and 0.1 mg kg-1) but significantly (P less than 0.05) slowed with higher doses of morphine. The increases in amount of gastric emptying induced by tifluadom, U-50488 and N-desmethyltrimebutine were abolished by previous administration of naloxone (0.1 mg kg-1 i.v.) and [(3-furylmethyl) noretazocine]-MR 22-66 (0.1 mg kg-1 i.v.). These results indicate that orally administered kappa, but not mu agonists at doses not exceeding 1 mg kg-1 enhance the amount of gastric emptying of a solid meal in dogs and suggest that this is due to a selective local stimulation of kappa mucosal or submucosal opiate receptors at antroduodenal level.

Comparison of the carbon 13-labeled octanoic acid breath test and ultrasonography for assessment of gastric emptying of a semisolid meal in dogs

To compare the rate of gastric emptying of a semisolid meal by use of the carbon 13-labeled octanoic acid breath test (13C-OBT) and gastric emptying ultrasonography (GEU) in dogs. 10 healthy dogs. Food was withheld from dogs for 12 hours before ingestion of a test meal (bread, egg, and skimmed milk) containing 13C-octanoic acid. The gastric antrum was visualized by use of a 6.5-MHz microconvex transducer, and the area of the ellipse defined by the craniocaudal and ventrodorsal diameters of the stomach was measured. Samples of expired air and antral images were obtained 30 minutes before ingestion of the test meal and then every 15 minutes for 4 hours and every 30 minutes for a further 2 hours. The half-dose recovery time with the 13C-OBT (t1/2[BT]) and the gastric half emtying time with GEU (t50%[GEU]) was calculated. Mean +/- SD values for the t1/2(BT) and t50%(GEU) were 3.44 +/- 0.48 hours and 1.89 +/- 0.78 hours, respectively. A significant correlation was detected between the t1/2(BT) and t50%(GEU), although there was a large (1.55 hours) mean difference between these indices. Results indicated that there was a correlation between the rate of solid-phase gastric emptying assessed by use of GEU and the 13C-OBT in dogs. Gastric emptying ultrasonography may be a useful, noninvasive method for assessment of the rate of solid-phase gastric emptying in dogs.

EVALUATION OF BAITS FOR DELIVERY OF ORAL RABIES VACCINE TO DOGS IN GUATEMALA

Acceptance of oral baits by dogs was evaluated in Guatemala. Eight bait matrix/attractant combinations were produced using commercial materials available in the United States. Two baits were produced using local materials in Guatemala. All baits included a plastic sachet that contained a placebo vaccine (water). Bait trials were conducted February-April, 2002, at five sites using 261 dogs. Bait acceptance ranged from 50.0% to 87.1%, and the combined proportion of sachets either swallowed or punctured ranged from 23.1% to 83.9%. The four bait types with the highest acceptance by dogs were the wax-coated sachet coated with poultry oil and poultry meal (87.1%), the dog meal polymer coated with poultry oil and poultry meal (82.8%), the fish meal polymer coated with poultry oil and poultry meal (77.4%), and the chicken head bait (77.8%). These four bait types were accepted most often as determined both by consumption and combined proportion of sachets swallowed or punctured (P = 0.0001). Future trials should demonstrate efficacy of oral rabies vaccination in Guatemala based on the use of selected bait matrices and the poultry oil/poultry meal attractant.

Forward of reverse gastric pacing do not affect gastric emptying of liquid meal in dogs

Forward of reverse gastric pacing do not affect gastric emptying of liquid meal in dogs

Forward of reverse gastric pacing do not affect gastric emptying of liquid meal in dogs

the changes in gastric motility, using electrugastrogram (EGG) and miniature pressure sensor placed in the antrum, and autonomic nerve functions after administration of CRH. [Subjects and Methods] 7 healthy volunteers participated in this study (6 male and 1 female, 18-22'].o.). EGG electrodes were attached on the bilateral mid-cravicular line of the hypochondrium and reference electrode was placed on 2cm above of the umbilicus. Dominant frequency of the EGG was calculated by FFT method. EGG frequency data were expressed as % of each range of the waves (Brady 1.6-2.4cpm, Normal 2.4-3.6cpm, Tachy >3.6). Antral manometry catheter was inserted into the gastric antrum and recorded in the data logger. Motility index (M.I.) was calculated by gastrointestinal motility software produced by White chapel Society. Heart rate variability were computed by holter ECG using FFT method and calculated LF/HF. EGG, gastric manometry and heart rate variability were recorded for 2 hr in the fasting period and 2 hr after administration of CRH (lOO/~g, bolus injection). Data, 20 minutes each, were calculated before and after CRH injection. Statistical evaluation was performed using Wilcoxon's signed-rank test. All the data were expressed as mean -+SD. [Conclusion] Peripheral injection of CRH has no influence on EGG, astral motility and sympathetic discharge in normal controls.

EM574, an erythromycin derivative, improves delayed gastric emptying of semi-solid meals in conscious dogs

The gastroprokinetic effects of de( N-methyl)- N-isopropyl-8,9-anhydroerythromycin A 6,9-hemiacetal (EM574), a non-peptide motilin receptor agonist, were investigated in conscious dogs in a normal state and with experimentally-induced gastroparesis. Gastric emptying of semi-solid meals was assessed indirectly from acetaminophen absorption with simultaneous recording of gastric antral motility. In the normal state, post-prandial intraduodenal administration of EM574 (30 mg/kg) stimulated antral motility and significantly enhanced gastric emptying as potently as did intravenous porcine motilin (0.003 mg/kg/h). Intraduodenal cisapride at 1 mg/kg denal cisapride at 1 mg/kg elicited antral contractions and tended to accelerate gastric emptying but at 3 mg/kg, gastric emptying was not enhanced despite a further increase in the motor index. In dogs with gastroparesis induced by intraduodenal oleic acid or intravenous dopamine, EM574 (0.03 mg/kg) increased antral motility and reversed the delayed gastric emptying completely. Cisapride (1 mg/kg) partially ameliorated the impaired emptying under these conditions. In atropinized dogs, no acceleration of gastric emptying by EM574 was observed. These results indicate that EM574 potently accelerates gastric emptying of caloric meals in dogs in a normal state and with experimentally-induced gastroparesis, and also suggest that the effect is mediated through stimulation of a cholinergic neural pathway.

Intraduodenal lipid inhibits central vagal stimulation of gastric acid secretion through activation of CCK a receptor in rats

Background: Intestinal lipids inhibit gastric acid secretion induced by meal in dogs and gastric emptying in rats via CCK and vagal capsaicin-sensitive afferent pathway (Lloyd et al: Gastroenterology, 102: 131,1992. Holzer et al: Am J Physiol267: G625, 1994). Intracisternal injection (ic) ofTRH is widely used to stimulate vagal efferent activity and mimics the cephalic phase of acid secretion. Aim: To investigate I) whether intraduodenal lipids inhibit central vagal gastric acid stimulation-induced by ic TRH analog; 2) whether CCK receptors are involved in these responses. Methods: Male SD rats (270-310 g) fasted for 24 h were anesthetized with urethane. Gastric acid secretion was induced by ic TRH analog, RX 77368 (5 ng) and measured by flushing the stomach through a gastric cannula. Intraduodenal (id) intralipid (0.5 ml) was administered through a duodenal fistula. Results: RX 77368 ic induced a net acid output of 56.8 ± 8.0 /Lmo1/90 min. CCK-8S (0.5 and 1 nmol/kg/h) iv infusion started 10 min before the ic RX 77368 inhibited the acid secretion by 23% and 82% respectively. The inhibitory action of CCK-8S was completely prevented by the CCK A receptor antagonist devazepide (l mg/kg) injected iv 10 min before the CCK-8S infusion. Intraduodenal intralipid (5%, 10% and 20%) administered 20 min before ic RX 77368 dose-dependently reduced by 24%, 83% and 100% the acid response and the inhibitory effect of intralipid was completely prevented by devazepide(l mg/kg). The CCK B receptor antagonist L-365260 (l mg/kg) had no effect on the inhibitory effect of intraduodenal lipid (Table). Conclusion: Intraduodenal lipid inhibits central TRH-induced gastric acid secretion through releasing endogenous CCK and the inhibitory action is mediated by CCK A receptors.

Candidate canine enterogastrones: acid inhibition before and after vagotomy

The relative contributions of several gut-derived peptides as enterogastrones known to be released in response to a fatty meal and to inhibit acid secretion have not previously been compared directly. We determined the acid-inhibitory activities of increasing intravenous doses of several peptides before and after highly selective vagotomy (HSV) during intragastric titration of a peptone meal in dogs. Before HSV, threshold inhibitory doses of peptide YY (PYY), cholecystokinin (CCK), and secretin were 5, 7, and 10 pmol.kg-1.h-1, respectively, whereas neurotensin, glucagon-like peptide-1 (GLP-1), and oxyntomodulin failed to inhibit acid secretion at doses up to 1,000 pmol.kg-1.h-1. The calculated dose producing 50% acid inhibition (ID50) of secretin (62 pmol.kg-1.h-1) was one-half that of PYY (128 pmol.kg-1.h-1). Maximal (90%) acid inhibition was produced by 100 pmol.kg-1.h-1 secretin and 500 pmol.kg-1.h-1 PYY. The highest dose of CCK that did not cause vomiting (100 pmol.kg-1.h-1) inhibited peptone-stimulated acid output by only 60%. After HSV, 500 pmol.kg-1.h-1. PYY and 200 pmol.kg-1.h-1 CCK failed to inhibit acid output by more than 50%. Threshold doses for inhibition by PYY and CCK were 200 and 100 pmol.kg-1.h-1, respectively. Secretin remained a potent inhibitor after HSV, with an ID50 of 80 pmol.kg-1.h-1 and a threshold dose of 10 pmol.kg-1.h-1. HSV also failed to affect inhibition caused by somatostatin. This study has shown that PYY and secretin are somewhat more potent and efficacious inhibitors of acid secretion than CCK but that all three peptides are far more active than GLP-1, neurotensin, and oxyntomodulin. PYY and CCK inhibit acid secretion in large part through vagal innervation of the gastric fundus, but the inhibitory effects of secretin are independent of fundic vagal innervation.

Role of nitric oxide in the renal hemodynamic response to a meat meal

Ingestion of a high-protein meat meal results in significant increases in renal plasma flow (RPF) and glomerular filtration rate (GFR). The mechanism involved in this hemodynamic response to the meat meal has not yet been fully elucidated. The present study was designed to test the hypothesis that nitric oxide (NO) is involved in the renal hyperemic responses to a meat meal. To test this hypothesis, renal hemodynamic response to a meat meal (10 g/kg) was determined in conscious, chronically instrumented dogs with (n = 9) and without (n = 7) an intrarenal NO synthesis inhibition with NG-nitro-L-arginine methyl ester (L-NAME, 3 micrograms.kg-1.min-1 intrarenally). Under control conditions, the meat meal resulted in significant renal hyperemia. Three hours after ingestion of the meat meal, GFR (43 +/- 3 to 59 +/- 6 ml/min) and RPF (128 +/- 10 to 160 +/- 17 ml/min) progressively increased by approximately 40 and 25%, respectively. In contrast, pretreatment with intrarenal infusion of L-NAME abolished the GFR (48 +/- 6 to 52 +/- 6 ml/min) and RPF (129 +/- 20 to 121 +/- 17 ml/min) increases induced by the meat meal. Pretreatment with L-arginine (0.5 mg.kg-1.min-1) plus L-NAME (3 micrograms.kg-1.min-1) did not modify the meat meal-induced changes in GFR (41 +/- 4 to 66 +/- 6 ml/min) and RPF (127 +/- 9 to 182 +/- 14 ml/min). In summary, a meat meal in dogs results in marked increases in RPF and GFR. Intrarenal NO synthesis inhibition abolished the RPF and GFR responses to the meat meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucose turnover after a mixed meal in dogs: glucoregulation without change in arterial glycemia.

Because the dog can respond to a mixed-meal challenge with little or no change in plasma glucose concentration, we used kinetic techniques to quantify the magnitude and duration of changes in glucoregulation. Glucose turnover was measured using [3-3H]glucose and [U-14C]glucose over two 19-h periods in healthy dogs, first during a fast (n = 6) and then throughout the postprandial state (n = 6) after a single mixed meal. Mean arterial glycemia remained constant in the fasted state (7.5 +/- 0.2 mM) and in the fed state (7.6 +/- 0.3 mM). Glucose appearance (Ra), however, increased slowly after the meal from 38 +/- 2 mg/min to a maximum of 79 +/- 8 mg/min after 6 h and stayed elevated until 12 h (P < 0.001). In parallel, glucose disappearance (Rd) rose from 35 +/- 3 to 83 +/- 7 mg/min, closely matching the corresponding Ra. Glucose recycling rose from 25 +/- 8% at baseline to a maximum of 53 +/- 15% (P < 0.05) at 14 h in fed dogs, whereas levels for fasted dogs stayed between 19 +/- 7% at 0 h and 27 +/- 12% at 6 h. Insulin levels rose significantly 30 min after the meal from 67 +/- 7 pM to a peak of 208 +/- 54 pM at 6 h but remained elevated for 12 h. We conclude that 1) the dog was able to maintain postprandial glucoregulation by very precise matching of Ra and Rd such as to maintain glycemia constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric and pancreatic lipase levels during a test meal in dogs.

The levels of gastric and pancreatic lipases in the duodenum and the jejunum were measured during the digestion of a test meal in dogs. Using both a specific enzymatic titration and an enzyme-linked immunosorbent assay, it is shown for the first time that gastric lipase remains active in the duodenal and jejunal contents. An experimental device was set up for measuring the secretions and the intestinal flows of lipases during the digestion of a liquid test meal. In a dog equipped with gastric and duodenal cannulae, the secretion of gastric lipase was stimulated by food ingestion, reaching 3.0 +/- 0.3 mg/h (three times the basal secretion rate) during the 1st h of digestion. The total secretory outputs of gastric and pancreatic lipases recorded over a 3-h period of digestion were 7.2 +/- 1.2 mg and 18.7 +/- 1.2 mg, respectively.

Inhibitory cholinergic effects of esaprazole on gastric secretion and plasma gastrin levels in the dog.

The effects of esaprazole, a novel antiulcer drug, on gastric acid secretion and plasma gastrin levels were investigated in dogs provided with a gastric fistula or Heidenhain pouch. Esaprazole affected in a different extent the tests performed on dogs with a gastric fistula. The greatest inhibitory effect was obtained against 2-deoxy-D-glucose-induced acid output and gastrin release. An intermediate inhibition by esaprazole was detected on bethanechol-evoked secretion, and the lowest activity was found versus histamine-stimulated secretion. All these responses were strongly inhibited by the antimuscarinic drug pirenzepine used as reference drug. Moreover, both esaprazole and pirenzepine prevented the acid secretory response to a test meal in dogs with a Heidenhain pouch, without significantly affecting plasma gastrin levels. The present results suggest that the depressant action of esaprazole on gastric secretion depends on its peripheral anticholinergic activity, consisting of a partial blockade of acid output and a main reduction of vagally mediated gastrin release. On the basis of these findings, the antiulcer activity of esaprazole might be in part ascribed to its inhibitory effects on gastric secretion.

Cholecystokinin receptor antagonist MK-329 blocks intestinal fat-induced inhibition of meal-stimulated gastric acid secretion

MK-329, a selective type A cholecystokinin (CCK) receptor antagonist, was given to dogs to test the hypothesis that CCK is one of the principal physiological enterogastrones mediating fat-induced decreases in gastric acid secretion. Gastric acid secretion in response to 300 mL 8% peptone meals was measured by intragastric titration to pH 5.5 in six awake dogs with chronic gastric, duodenal, and jejunal fistulas. Gastric emptying was measured by a dye-dilution technique. During the last hour of peptone stimulation, the intestine was perfused with either control solution or 20% lipid (Intralipid; Kabi Vitrum, Alamedo, CA) intraduodenally or intrajejunally. Compared with control perfusions, mean gastric acid outputs were decreased significantly after lipid perfusion of the duodenum (47% of control) and jejunum (24% of control). Similarly, mean gastric emptying rates were significantly less after lipid perfusion of the duodenum (56%) and jejunum (26%). Oral pretreatment with MK-329 (1 mg/kg) significantly reversed the inhibition of gastric acid output caused by lipid perfusion of the duodenum and jejunum, but fat-induced inhibition of gastric emptying was not significantly affected. These studies provide evidence for an important inhibitory role for CCK as an enterogastrone but do not implicate CCK as being important in fat-induced delayed gastric emptying of a liquid meal in dogs.

Regulation of renal hemodynamics after protein feeding: effects of loop diuretics

These studies were designed to test the hypothesis that the renal vasodilation and increased glomerular filtration rate (GFR) after a high-protein meal are mediated by the tubuloglomerular feedback (TGF) mechanism. In eight chronically instrumented conscious dogs, a meal of raw beef (10 g/kg) caused GFR to increase from 66 +/- 5 to 90 +/- 7 ml/min and effective renal plasma flow (ERPF) to increase from 191 +/- 25 to 281 +/- 24 ml/min, while plasma alpha-amino N levels rose from 4.0 +/- 0.1 to 7.3 +/- 0.6 mg/dl. On another day the dogs were given an infusion of furosemide to block TGF, and fluid and salt losses were continuously replaced. Furosemide alone caused GFR to increase in most animals, although the average change did not reach statistical significance, and ERPF increased by 31%. Sodium excretion rose from 15 +/- 5 to 2,390 +/- 280 mueq/min, and urine flow rose from 1.17 +/- 0.22 to 20.5 +/- 2.4 ml/min. Autoregulatory capability was also abolished (autoregulatory index = 0.87 +/- 0.09 compared with 0.19 +/- 0.05 before furosemide). However, there was no significant change in GFR and ERPF after a subsequent meat meal in dogs receiving furosemide. On another day, some of the dogs were given another loop diuretic, ethacrynic acid, which caused no change in GFR, whereas its effects on ERPF, sodium excretion, and urine output were similar to those of furosemide. There were also no changes in GFR or ERPF after a meat meal during ethacrynic acid administration, despite normal increases in plasma alpha-amino N.(ABSTRACT TRUNCATED AT 250 WORDS)

Action of endogenous prostaglandins on postprandial pyloric motility: A possible modulation by fats

The involvement of endogenous prostaglandins (PGs) and the effect of exogenous PGs on the myoelectrical activity of the pylorus were examined for 6 hours after a meal in dogs chronically fitted with intraparietal electrodes on the gastroduodenal junction. The animals received either a standard meal or a fat meal which consisted of canned food added or not (standard meal) with arachis oil. The cyclooxygenase inhibitors, indomethacin (1 mg/kg) and piroxicam (0.2 mg/kg) given prior a fat meal singificantly increased the frequency of pyloric spike bursts did not modify the pyloric motility associated with a standard meal. Synthetic derivatives of PGE1 (misoprostol, 5–10 μg/kg) or PGE2 (enprostil 0.5–1 μg/kg) reduced the frequency of pyloric contractions after a fat but not a standard meal. It is suggested that both endogenous and exogenous prostaglandins may modulate postprandial pyloric motility when fats are present in sufficient amount into the meal.