Ian L. Taylor's research while affiliated with Tulane University and other places

Publications (141)

Article
Two trials were conducted to investigate the efficacy of in ovo administration of various dosages of peptide YY (PYY) on jejunal glucose absorption in hatchling poults from two strains of turkeys, Egg Line (EL) selected for egg production and British United Turkey (BUT) selected for growth. In both trials, either 100 µl saline (1.025% w/v) or sa...
Article
Neuropeptide Y (NPY) and peptide YY (PYY) are members of the pancreatic polypeptide family which have a high degree of primary and tertiary structural homology. They function as neurotransmitters and humoral agents in central nervous system and gastrointestinal function. During the last two decades, NPY body fluid concentrations and NPY/PYY brain r...
Article
The effects of in ovo peptide YY (PYY) or epidermal growth factor (EGF) administration on chick growth, yolk absorption and yolk stalk function in posthatch (0-5 days) meat-type or broiler chicks were determined. At Day 18 of incubation, treated eggs were injected into the air cell with 100 microl of either PYY (Trial 1) or EGF (Trial 2) at a dosag...
Article
Neuropeptide Y (NPY) and peptide YY (PYY) are members of the pancreatic polypeptide family which have a high degree of primary and tertiary structural homology. They function as neurotransmitters and humoral agents in central nervous system and gastrointestinal function. During the last two decades, NPY body fluid concentrations and NPY/PYY brain r...
Article
We have previously reported the Ts65Dn (Ts) mouse has impaired intestinal absorptive function and amino acid metabolism. Peptide YY (PYY) has enhanced glucose absorption in mice and turkeys. Other studies have reported that persons with Down syndrome have increased intestinal absorption of aluminum. Alzheimer's-like lesions have been reported in Ts...
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Full-text available
The effects of in ovo Peptide YY (PYY) administration on growth and feed conversion ratios in a commercial broiler line were investigated. Six hundred Ross male x Cobb female eggs were administered either 0.9% saline (control) or 600 microg/kg egg weight PYY in ovo at Day 18 of incubation. On day of hatching, 210 birds from each treatment group wer...
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In recent years, there has been a growing perception that limitations in gastrointestinal absorption may be detrimental to posthatch survival and subsequent performance. This perception is based on a large body of information demonstration that genetic selection for growth in domestic poultry alters intestinal structure from that of their wild coun...
Article
Mice trisomic for the distal portion of MMU 16 (Ts65Dn) were examined for differences in jejunal function and plasma amino acids as compared to diploid controls. Eighteen control and 19 Ts65Dn mice were compared for whole-body and intestinal O2 consumption, jejunal glucose uptake, and plasma amino acid concentrations. Ts65Dn mice consumed less (P <...
Article
Intestinal glucose absorption occurs via Na+-dependent glucose cotransporters (SGLT1) located in the luminal membrane of enterocytes and is driven by an electrochemical gradient maintained by Na+/K+ ATPase located on the basolateral membrane. Twenty percent of whole animal energy expenditures can be accounted for by the gastrointestinal tract, most...
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To investigate the role of hypercorticism in the development of compromised beta-adrenergic signalling in adipocytes of mature C57BL/6J-ob/ob mice. DESIGN AND EXPERIMENTAL UNITS: Mature male ob/ob mice and their lean littermates were treated with vehicle or the specific glucocorticoid receptor (GR) antagonist, RU-486 (30 mg/kg bw/d) for 21 d. Blood...
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The role of hypercorticism in the development of compromised beta-adrenergic signaling in adipose tissue was assessed in ob/ob mice adrenalectomized at 4 weeks of age and studied 1 and 3 weeks thereafter. Adrenalectomy prevented the rapid increase in body weight and fat deposition between 4 and 5 weeks of age in ob/ob mice and produced a phenotype...
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Full-text available
The role of hypercorticism in the development of compromised beta-adrenergic signaling in adipose tissue was assessed in ob/ob mice adrenalectomized at 4 weeks of age and studied 1 and 3 weeks thereafter. Adrenalectomy prevented the rapid increase in body weight and fat deposition between 4 and 5 weeks of age in ob/ob mice and produced a phenotype...
Article
Pancreatic polypeptide (PP) is a regulatory peptide that modulates gastrointestinal function. Previously we demonstrated PP receptors in the brainstem and interpeduncular nucleus, and the PP receptors in the brainstem appear to modulate gastric motility and pancreatic exocrine secretion. The purpose of this study is to extend our understanding of t...
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Full-text available
The role of hypercorticism in the development of compromised b-adrenergic signaling in adipose tissue was assessed in ob/ob mice adrenalectomized at 4 weeks of age and studied 1 and 3 weeks there- after. Adrenalectomy prevented the rapid increase in body weight and fat deposition between 4 and 5 weeks of age in ob/ob mice and pro- duced a phenotype...
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Full-text available
Terminal hydrolysis of oligosaccharides at the small intestinal brush border yields monomeric glucose, most of which is then absorbed by the transepithelial route. This involves carrier-mediated processes requiring specialized functional proteins situated in the brush border (SGLT1) and basolateral (GLUT2) membranes. Glucose translocation at the en...
Article
Sixteen Dorset crossbred ewes were used to determine the effect of recombinant methionyl bovine somatotropin (bST) on small intestinal nutrient absorption. Ewes were kept indoors in individual pens and allowed free access to a concentrate diet (18% CP). bST (150 μg kg-1) or saline were subcutaneously injected once daily for 10 d. An in vitro assay...
Article
We have very recently shown that intracisternal injection of apolipoprotein A-IV (apo A-IV), a glycoprotein produced in the small intestine by fat, dose-dependently inhibited gastric acid secretion in pylorus-ligated conscious rats. These results suggest that apo A-IV acts centrally as a neuromodulator to inhibit gastric secretion. The present stud...
Article
We recently showed that intracisternal injection of apolipoprotein A-IV (apo A-IV), a protein produced by the small intestine in response to fat, inhibits gastric acid secretion. The aim of this study was to investigate the mechanism of acid inhibition by central apo A-IV. Gastric acid secretion was determined in pylorus-ligated conscious rats. The...
Article
Thyrotropin-releasing hormone (TRH) stimulates pancreatic exocrine secretion through the vagus nerve when injected into rat cerebrospinal fluid. However, little is known about the exact site of action of TRH in the brain to stimulate pancreatic secretion. Recent neuroimmunochemical and neurophysiological studies suggest that TRH could be a neurotra...
Article
Various tissues were obtained from the well-characterized genetic model (C57BL/6J-ob/ob) of non-insulin-dependent diabetes mellitus (NIDDM) and from a diet-induced model of NIDDM produced in the same genetic background (C57BL/6J). The objectives were to determine whether the previously observed changes in guanine nucleotide-binding regulatory prote...
Article
Pancreatic polypeptide (PP), a hormone released from the pancreas, inhibits pancreatic secretion in vivo but not in vitro, suggesting that the inhibitory action of PP on pancreatic secretion is indirect. Circulating PP in physiological concentrations binds to specific receptors in the dorsal vagal complex in the brainstem. Therefore, the hypothesis...
Article
Epididymal adipocytes were isolated from Fischer 344 rats aged 3, 6, 12, and 24 months, to study the mechanisms responsible for age-dependent diminution in cellular adrenergic responsiveness. Messenger RNA (mRNA) levels for the beta 1-, beta 2-, and beta 3-adrenergic receptors (ARs) were compared across age groups and related to adenylyl cyclase ac...
Article
Various tissues were obtained from the well-characterized genetic model () of non-insulin-dependent diabetes mellitus (NIDDM) and from a diet-induced model of NIDDM produced in the same genetic background (C57BL/6J). The objectives were to determine whether the previously observed changes in guanine nucleotide-binding regulatory protein (G protein)...
Article
Epididymal adipocytes were isolated from Fischer 344 rats aged 3, 6, 12, and 24 months, to study the mechanisms responsible for age-dependent diminution in cellular adrenergic responsiveness. Messenger RNA (mRNA) levels for the beta 1-, beta 2-, and beta 3-adrenergic receptors (ARs) were compared across age groups and related to adenylyl cyclase ac...
Article
We evaluated the effect of 2-deoxy-D-glucose (2-DG) on gastric emptying of a non nutrient solution in conscious rats using a Phenol red method. Intravenous injection of 2-deoxy-D-glucose dose-dependently increased the rate of gastric emptying. This stimulatory action of 2-DG was abolished by subdiaphragmatic vagotomy. Intracisternal injection of th...
Article
These studies examined the effect of 2-deoxy-D-glucose (2-DG) on gastric mucosal integrity. Intravenous administration of 2-DG in doses of 100 and 125 mg/kg dose-dependently produced multiple, hemorrhagic gastric mucosal lesions while 75 mg/kg of 2-DG failed to induce gastric lesions. Intracisternal injection of 2-DG in doses of 10 and 20 mg/kg als...
Article
We have recently reported that apolipoprotein A-IV (apo A-IV), a protein associated with lipoproteins, acts in the brain to inhibit gastric acid secretion. In the present study, we determined whether or not apo A-IV has an anti-ulcer action via the central nervous system using Sprague-Dawley rats. Intracisternal injection of apo A-IV dose-dependent...
Article
Fat feeding increases not only serum but also cerebrospinal fluid concentration of apolipoprotein (apo) A-IV, a protein produced mainly by the small intestine in the rat. We hypothesized that apo A-IV may have a central effect on gastric secretion. Gastric juice was collected by the pylorus ligation method. Rats underwent pylorus ligation and recei...
Article
We have recently reportd that apolipoprotein A-IV (apo A-IV), a protein associated with lipoproteins, acts in the brain to inhibit gastric acid secretion. In the present study, we determined whether or not apo A-IV has an anti-ulcer action via the central nervous system using Sprague-Dawley rats. Intracisternal injection of apo A-IV dose-dependentl...
Article
The present study was carried out to investigate the central effects of pancreatic polypeptide on gastric secretion and gastric ulcer formation in conscious rats. Intracisternal injection of rat pancreatic polypeptide (62.5, 250, and 1000 ng/rat) into pylorus-ligated rats resulted in a dose-dependent stimulation of gastric acid and pepsin secretion...
Article
In the present study, we evaluated the effects of central administration of pancreatic polypeptide (PP) on gastric emptying of a liquid meal in conscious rats using a phenol red method. Intracisternal injection of PP (0.5-2.0 micrograms) speeds gastric emptying of a test meal in a dose-dependent manner. In contrast, i.p. injection of PP at the same...
Article
G proteins are heterotrimeric membrane-associated proteins that couple a large number of receptors to a variety of effector systems within the cell. Characterization of G proteins expressed in a particular cell type represents an important first step in defining the potential candidates to which a receptor might couple. A difficulty often encounter...
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Neuropeptide Y (NPY) has been suggested to exert antinociceptive actions by inhibiting the release of neurotransmitters from trigeminal and dorsal root ganglia (DRG) neurons, but the site of direct NPY action in vivo and the NPY receptor subtype mediating these effects are unknown. 125I-peptide YY (PYY) was used to localize and characterize NPY rec...
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Adipocytes from genetically obese (ob/ob) mice display an impaired response to beta-adrenergic stimulation, but the molecular defects have not been unequivocally identified. The expression and functional activity of the beta 1-, beta 2-, and beta 3-adrenergic receptor (AR) subtypes in white and brown adipose tissue from genetically lean and obese (...
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The effects of epidermal growth factor on intestinal glucose transport were examined in mice. Glucose transport measurements were performed using an in vitro assay system that estimated the rate of accumulation of [3H]3-O-methyl-D-glucose. In Experiment 1, two-mo-old male and female mice were subcutaneously injected once daily with 0, 150 or 300 mi...
Article
The rationale for this study was to test the hypothesis that peripherally released peptide YY (PYY) acts in the vagal nuclear complex of the medulla oblongata to modulate vagal tone centrally. The objective was to determine whether circulating PYY gains access to and binds to the receptors identified in the dorsal vagal complex (DVC) under physiolo...
Article
The influence of peripheral injection of peptide YY (PYY) on neuronal activity in the rat brain was examined by immunohistochemical detection of c-fos protein. Numerous c-fos-immunoreactive nuclei were found in the area postrema, nucleus tractus solitarius (commissural and medial subnuclei), central amygdala and thalamus (periventricular and medial...
Article
Neuropeptide Y (NPY), a centrally located neurotransmitter, is known to increase appetite in fasted and satiated animals. In addition to evaluating NPY's effect on eating behavior, this study was intended to determine whether intracerebroventricular (ICV) NPY would have an effect on canine gastric and pancreatic secretion. Four dogs were prepared w...
Article
Peptide YY is released into the circulation after ingestion of a meal, a response that is markedly enhanced in patients with malabsorption. The enhanced release of peptide YY slows gastric emptying and transit of meals through the small intestine. The net effect is increased efficiency of digestion and absorption of nutrients. Once the efficiency o...
Article
[125I]Peptide YY was used to localize and characterize peptide YY and neuropeptide Y receptor binding sites in the heart. In the rat and rabbit heart, nearly every artery and arteriole that could be histologically identified also expressed saturable binding sites for [125I]peptide YY. In the arteries, these [125I]peptide YY binding sites were prima...
Article
Quantitative receptor autoradiography localized a high-affinity binding site for 125I-peptide YY to the mucosa in rabbit distal colon. Scatchard binding analysis revealed a single-affinity binding site (KD = 0.29 nM) with binding specificity similar to other peptide YY-preferring receptors (peptide YY > or = neuropeptide Y > pancreatic polypeptide)...
Article
A rise in intracellular calcium is the predominant signal that leads to the activation of the contractile machinery in gastrointestinal smooth muscle. The primary sources of activating calcium are illustrated in Fig. 2. Voltage- and peptide-mediated release of intracellular calcium contribute to activation of some gastrointestinal smooth muscles. H...
Article
Gastrointestinal functions are precisely regulated by hormonal and neural negative feedback loops. In addition to the classic hormonal and vago-vagal reflex mechanisms, these studies indicate that there are direct actions of gut hormones on the dorsal vagal complex. The current data demonstrate that pancreatic polypeptide is released into the circu...
Article
Distal colonic motor activity was measured in 12 control subjects and seven constipation-predominant irritable bowel syndrome patients to examine the effects of intravenous administration of cholecystokinin. In the basal state, no significant motility differences were noted between these two groups. Following the intravenous administration of the h...
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Full-text available
We report here the identification on rat liver plasma membranes and microsomes of proteins that bind pancreatic polypeptide (PP) with high affinity and specificity (plasma membranes: KD = 4.6 nM, Bmax = 3.28 pmol/mg protein; microsomes: KD = 3.45 nM, Bmax = 18.7 pmol/mg protein). These binding proteins appeared coupled to a G-protein, since 0.1 mM...
Article
Pancreatic polypeptide (PP) is released from pancreatic islets after meals or in response to stress. Although PP exhibits a wide spectrum of biological effects, few, if any, are mediated by a direct action of PP on its ultimate target organ. Recently, PP receptors have been identified in areas of the brain with an incomplete blood-brain barrier sug...
Article
Mechanisms regulating ruminant pancreatic exocrine function differ in some respects from those in nonruminants. This may affect the post-ruminal digestion of certain dietary nutrients such as starch. Ruminants do not exhibit clearly defined cephalic and gastric phases of pancreatic regulation, a likely consequence of the continuous nature of digest...
Article
The in vivo and in vitro treatment effects of pancreatic polypeptide (PP) were characterized by studying agonist-stimulated enzyme secretion in pancreatic acini prepared from 8-week-old mice treated for 2 days with PP (200 micrograms kg-1 day-1) and in pancreatic lobules from untreated male rats. In the mouse studies, enzyme secretion was evaluated...
Article
In two previous studies, postprandial pancreatic polypeptide (PP) release was inhibited when pancreatic denervation was combined with distal pancreatectomy. In contrast, postprandial PP release was unaffected by pancreatic denervation without a distal pancreatectomy. These findings suggested a role for the distal pancreas in regulation of postprand...
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Full-text available
Messenger RNA levels for the alpha subunit of G-proteins expressed in adipocytes of lean and obese (ob/ob) mice were compared with relative levels of the encoded proteins. Using both toxin labeling and Western blots, expression of Gs alpha, Gi alpha-1, and Gi alpha-3 was decreased by approximately 2-fold in adipocytes of obese mice, while levels of...
Article
The effects of substance P, cholecystokinin and neuropeptide Y were examined on rabbit distal colonic motility. All three agents produced increased contractile activity but the mechanisms responsible differed depending on the agent tested. In the intact animal, peptide effects were measured under basal conditions and following exposure to atropine,...
Article
Pancreatic polypeptide and peptide YY are inhibitors of pancreatic exocrine secretion in vivo but not in vitro, which suggests secondarily mediated mechanism(s) of action. To determine the role of extrinsic neural and intrinsic cholinergic elements on this inhibitory effect, a total of nine dogs underwent two-stage extrapancreatic denervation and c...
Article
Available data on the effect of neuropeptide Y (NPY) on insulin release are conflicting and little data exist regarding the effect of NPY on glucagon secretion. The purpose of the present study, therefore, was to characterize the direct effect of NPY on the release of these pancreatic hormones and to examine the role of glucose on these interaction...
Article
The neuropeptide Y (NPY) receptor was solubilized from rat brain membranes with the zwitterionic detergent 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS). The binding of 125I-NPY to CHAPS extracts was protein, time, and temperature dependent. Unlabeled NPY and the related peptides peptide YY (PYY) and pancreatic polypeptide inhi...
Article
Peptide YY (PYY), a newly discovered ileocolonic peptide, is released by nutrients in the proximal and distal intestine and inhibits pancreatic secretion. However, it is not clear whether PYY can be released in the absence of nutrients in the intestine or whether a physiological role exists for endogenous PYY in negative feedback regulation of panc...
Article
1. Smooth muscle from six sites in the cat gastrointestinal tract was evaluated with respect to its ability to generate contractions in calcium-free solutions. 2. Membrane depolarization and carbachol, but not cholecystokinin or neurotensin, increased tension in smooth muscle segments of esophagus, corpus, duodenum, ileum, proximal colon and distal...
Article
Chronic treatment with bovine pancreatic polypeptide (bPP) is reported to decrease body weight and reduce fasting glucose and insulin concentrations in congenitally obese mice. The present study examines the effects of acute and chronic bPP treatment on insulin release and glucose clearance in lean and obese rodents. After single injections of 0, 5...
Article
Pancreatic polypeptide (PP) inhibits pancreatic exocrine secretion by indirect mechanisms that may be centrally mediated. The central site of action of PP that results in inhibition of pancreatic secretion has not been identified. Using autoradiography to identify 125I-PP binding to frozen sections of rat brain, we have identified saturable, high-a...
Article
Six mongrel dogs with gastric and esophageal fistulas (n = 4) or with gastric and pancreatic fistulas (n = 2) were studied to determine the role of taste on gastric and pancreatic secretion. Stimulation of the back of the throat with a range of tastants produced gastric acid, bicarbonate, protein, and pancreatic polypeptide levels that were statist...
Article
A cholecystokinin (CCK) receptor antagonist, MK-329, was used to explore the physiological role of CCK in regulating pancreatic endocrine function in humans. The ability of CCK to increase plasma pancreatic polypeptide (PP) concentrations and blockade of this effect with MK-329 were evaluated in a double blind, balanced, four-period cross-over stud...
Article
In previous studies, postprandial pancreatic polypeptide (PP) release was diminished when pancreatic denervation was combined with distal pancreatectomy in animals without chronic fistulae. In contrast, postprandial PP release was reported to be unchanged when the pancreas was denervated without performing a distal pancreatectomy. These findings we...
Article
Isolated rat ventricular cardiomyocytes were used to study the effects of insulin on glycogen metabolism in cells treated with various agents that activate adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase. Incubation of myocytes with isoproterenol produced a rapid concentration-dependent increase in cAMP concentration, cAMP-depe...
Article
Full-text available
Neuropeptide Y (NPY), a neurotransmitter contained within intrinsic nerves of the small intestine, inhibits secretion when added to the serosal side of intestinal mucosa mounted in Ussing chambers. Using NPY radiolabeled with IODO-GEN, lactoperoxidase, or the Bolton-Hunter reagent, we have localized high affinity NPY receptors to the serosal latero...
Article
Neuropeptide Y (NPY) is widely distributed in the central and peripheral nervous systems where it serves neuromodulator and neurotransmitter functions. NPY is contained within intrinsic nerves of the small intestine and can be demonstrated to inhibit intestinal secretion when added to the serosal side of intestine mucosa mounted in Ussing chambers....
Article
The impact of changes in the activation state of the low Km cAMP phosphodiesterase (PDE) on cAMP output in adipocyte membranes was assessed by measuring the product of cAMP synthesis and degradation in the membrane preparation simultaneously. Crude membranes were prepared from adipocytes treated with the cAMP analog, 8-pCl phi S-cAMP and from adipo...
Article
Little is known about how gastric and pancreatobiliary responses differ after intake of elemental diets from responses to polymeric food. We therefore compared pancreatic and biliary secretions after gastric instillation of albumin (7 g%, with dextrose 21 g%) with an elemental diet in 6 healthy volunteers. The elemental diet contained amino acids (...
Article
To clarify the role of GIP (gastric inhibitory polypeptide) as an incretin, we related temporally the gastric emptying of fat, protein and glucose to plasma levels of glucose, GIP and insulin in man. Five healthy volunteers with a multiple lumen duodenal tube ingested a mixed meal with phase-specific markers for the aqueous phase, liquid fat and th...
Article
Forty-eight Suffolk ram lambs were divided into four groups of 12 and the animals in two of the groups were surgically castrated at weaning. All animals were placed in a controlled environment and half of the animals of each sex phenotype (12 rams, 12 wethers) were exposed to 8 h light followed by 16 h dark (short photoperiod), and half of the anim...
Article
In the present studies we examined the distribution, release, and biological actions of peptide tyrosine tyrosine (PYY) in the rat. The concentration and distribution of PYY was highest in the ileum and colon as determined by both radioimmunoassay of rat tissue extracts and immunocytochemistry. An ultrastructural comparison of rat and dog colonic P...
Article
The receptor for neuropeptide Y (NPY) was identified on rat brain membranes after covalent labeling with 125I-NPY using the homobifunctional cross-linkers disuccinimido suberate and disuccinimido dithiobis(propionate) and the heterobifunctional photoactive cross-linker succinimido 4-azidobenzoate. Analysis by sodium dodecyl sulfate-polyacrylamide g...
Article
The influence of gastric emptying of nutrients on plasma cholecystokinin and pancreatobiliary functions is poorly understood. We therefore temporally related the emptying of fat, protein, and glucose of a mixed meal to release of the gut hormones cholecystokinin, pancreatic polypeptide, and peptide YY and outputs of trypsin, lipase, bilirubin, and...
Article
To determine whether viscous fibers improve glucose tolerance by slowing gastric emptying or impeding intestinal uptake of glucose, 800 mL of 0.2 mol glucose/L were instilled into the stomachs of the dogs and allowed to empty from the stomach out the proximal limb of a duodenal fistula while simultaneously fresh solution was instilled into the dist...
Article
In the present study we report methods for the isolation and culture of colonic peptide YY (PYY) cells and have tested the effects of sodium oleate and other chemotransmitters on PYY release. Enzyme-dispersed canine colonic mucosa cells were separated by a Beckman elutriation rotor, and the enriched PYY fraction was cultured on type I collagen in f...
Article
The delay in gastric emptying after a meal isthought to result from nutrient distention-induced release of peptides and neurotransmitters in the gut. The potential contribution of the brain and central neuropeptides to the postprandial regulation of gastric emptying has not been studied adequately. The purpose of this study was twofold: to examine...
Article
Gastric emptying of solids and liquids was evaluated simultaneously in 11 patients with intestinal pseudoobstruction. Despite a normal upper gastrointestinal series in most patients, over two thirds of the patients had abnormal gastric emptying of solids and/or liquids. Half these patients exhibited delayed emptying of solids and accelerated emptyi...
Article
The effects of peptide YY (PYY) on cholecystokinin-stimulated gallbladder contraction were investigated in the prairie dog model. Twelve animals underwent laparotomy with catheter placement into the gallbladder and common bile duct (vent). The gallbladder was continuously perfused with [14C]polyethylene glycol-labeled lactated Ringer at 0.03 ml/min...
Article
The hypothesis that pancreatic polypeptide promotes postcontractile gallbladder filling was tested in the prairie dog model. Fifteen animals underwent laparotomy with catheter placement into the gallbladder, distal common bile duct (vent), and femoral vein. The gallbladder was perfused with [14C]polyethylene glycol labeled lactated Ringer's solutio...
Article
Dogs with chronic pancreatic fistulae were given 0.5 ml of nonimmune rabbit serum or antibody S5, an antibody raised against the C-terminal pancreatic polypeptide (PP) hexapeptide. A 3-h infusion of secretin (125 ng/kg/h) and CCK8 (50 ng/kg/h) was started 30 min after injecting serum. Exogenous BPP (400 pmol/kg/h) was administered during the middle...
Article
Peptide YY is a candidate enterogastrone localized to endocrine cells of the ileocolonic mucosa. The purpose of the present study was to determine if blood levels of peptide YY observed after perfusion of the intestine with fatty acids are capable of slowing gastric emptying. Gastric emptying of a 300-ml saline meal was monitored during intravenous...
Article
Intraluminal fat inhibits gastric secretion through as yet undetermined mechanisms which involve release of one or more hormonal enterogastrones. As intraluminal fat releases Peptide YY (PYY) in amounts sufficient to inhibit meal-stimulated acid secretion, this ileo-colonic peptide exhibits the characteristics required of an enterogastrone. The pre...
Article
The present study examines peptide YY responses to regional intestinal perfusion of fatty acids of different chain length--dodecanoate and oleate. Six dogs with chronic gastric, duodenal, and jejunal fistulas were studied. Proximal perfusates were administered into the duodenum and diverted through an intestinal fistula placed 45 cm beyond the duod...
Article
Peptide YY is an ileocolonic peptide that inhibits meal-stimulated pancreatic secretion when infused in a dose of 400 pmol/kg X h. In this study pancreatic secretion was monitored in response to increasing doses of secretin or cholecystokinin-octapeptide (62.5, 125, 250, and 500 ng/kg X h) during the simultaneous infusion of either saline or peptid...
Article
Cholecystokinin, bombesin and pancreatic polypeptide are all reported to induce satiety in rodents. To test the hypothesis that cholecystokinin and bombesin induce satiety through release of pancreatic polypeptide, we compared the satiety inducing properties of each peptide in rats trained to eat a liquid diet (Magnacal). Studies were repeated afte...
Article
Recent studies suggest that pancreatic polypeptide (PP) alters gallbladder pressure and reduces delivery of bile to the duodenum. Whether this peptide influences gallbladder emptying and/or filling is not clear. Using the prairie dog model, we tested the hypothesis that exogenous PP induces gallbladder filling. Animals maintained on control diets u...
Article
To establish normal values for gastric secretory function in preterm infants, we studied 34 healthy preterm infants once a week during hospitalization. Basal acid output, pentagastrin-stimulated acid output, fasting serum gastrin, and fasting serum pancreatic polypeptide were measured during each study. Basal acid output at 1 week of age was 12 mum...
Article
Considerable disagreement exists as to whether prostaglandins improve survival in animals with experimental pancreatitis. In prior studies we have demonstrated a beneficial effect of prostaglandin in the choline deficient, ethionine supplemented diet model of acute hemorrhagic pancreatitis. In the present study we have examined the effects of 1) de...
Article
Peptide YY was recently isolated from porcine intestine and shown to exhibit marked structural homology with pancreatic polypeptide, a potent inhibitor of pancreatic exocrine secretion. We have examined the effects of infused peptide YY on gastric and pancreatic secretion in four mongrel dogs with gastric and pancreatic fistulas. A 15% liver extrac...
Article
This study examined pancreatic polypeptide responses to isocaloric meals of radioactively labeled glucose or starch in six normal and seven vagotomized subjects. Liquid glucose meals were ingested with the subject both erect and supine and starch meals were ingested in the upright posture as a solution and as solid balls. In normal subjects, each m...
Article
We evaluated carbohydrate tolerance in nine thin cystic fibrosis (CF) patients and in six controls, measuring responsiveness to the following insulinotropic secretagogues: oral glucose, IV glucose, and IV tolbutamide. Glucose responses segregated patients into two groups: Group I with normal carbohydrate tolerance associated with normal to slightly...