Bovine Pancreatic Polypeptide Research Articles

Distinct localization of FMRFamide- and Bovine Pancreatic Polypeptide-like material in the brain, retrocerebral complex and suboesophageal ganglion of the cockroach Periplaneta americana L.

One bovine pancreatic polypeptide (BPP) antiserum and two FMRFamide antisera were applied in the peroxidase-antiperoxidase (PAP) immunohistochemical technique on a complete series of sections of brains, suboesophageal ganglia (SOG), corpora cardiaca (CC) and corpora allata of Periplaneta americana L. Double immunohistochemical staining demonstrated that the same perikarya and processes were stained by both the BPP and FMRFamide antisera. This was caused by cross-reaction of the BPP and FMRFamide antisera with common antigenic determinants as was shown by a number of solid-phase absorptions. Application of a third FMRFamide antiserum, which was especially selected for its inability to react with bovine and avian pancreatic polypeptide, showed that more than half of the structures that were stained with the ‘unspecific’ BPP and FMRFamide antisera, contained material which was genuinely FMRFamide-like. This peptide material was located in cerebral neuronal structures, in the SOG, in the storage site of the CC and in numerous nerve fibres throughout the neuropile regions, which suggested a neurotransmitter/modulator as well as a neurohormonal role. The FMRFamide-like peptide was also found to be present in the same brain sites as an adipokinetic hormone-like peptide, but double labelling revealed that these two substances were never located in the same perikarya or fibres.

Distribution of neuropeptide Y in the forebrain and diencephalon: an immunohistochemical analysis

The distribution of neuropeptide Y (NPY)-like immunoreactive (NPYI) structures in the rat forebrain and upper brainstem was examined by means of indirect immunofluorescence and peroxidase-antiperoxidase methods. The present study has demonstrated a much wider and more abundant distribution of NPYI structures in the forebrain and diencephalon than earlier studies in which antisera against avian pancreatic polypeptide or bovine pancreatic polypeptide were used, suggesting that NPY is involved in a variety of brain functions.

Action of pancreatic polypeptide on rat pancreatic secretion: in vivo and in vitro

The biological activity of bovine pancreatic polypeptide (BPP) on rat exocrine pancreatic secretion was compared in vivo and in vitro. In anesthetized rats prepared with a bile-pancreatic duct cannula, BPP inhibited cholecystokinin (CCK)-stimulated (10 IDU . kg-1 X h-1) protein secretion in a dose-related manner (P less than 0.001). CCK, from 5-20 IDU . kg-1 X h-1, did not alter the degree of inhibition by BPP at 40 micrograms . kg-1 X h-1, suggesting a nonsurmountable inhibition. Analogues of BPP, including rat pancreatic polypeptide, neuropeptide Y, peptide YY, and the C-terminal hexapeptide of PP, also inhibited CCK-stimulated protein secretion. To determine whether BPP acts directly on acinar cells to suppress enzyme secretion, in vitro studies were performed. BPP and its analogues did not suppress octapeptide of CCK (CCK-8)-stimulated amylase release from either isolated rat pancreatic acini or preparations of pancreatic lobules. Specific binding of 125I-BPP to pancreatic acini was also not observed. From our data we conclude that BPP acts to inhibit pancreatic enzyme secretion in the rat in a noncompetitive manner. Absence of an effect by BPP or its analogues in vitro coupled with an absence of 125I-BPP binding to acini suggest that the inhibitory action of PP on exocrine pancreatic function is mediated by indirect mechanisms.

An FMRFamide antiserum differentiates between populations of antigens in the ventral nervous system of the locust, Schistocerca gregaria

The distribution of FMRFamide immunoreactive neurones in the ventral nerve cord of the locust, Schistocerca gregaria, is described. These neurones are found only in the suboesophagael and thoracic ganglia, although immunoreactive processes are found in the neuropils of the abdominal ganglia. Many of these neurones also react with an antiserum raised against bovine pancreatic polypeptide (BPP), but this antiserum also reveals another population of cells in the abdominal ganglia. The staining obtained with the BPP antiserum is blocked by preabsorption of the antiserum with FMRFamide; the converse is not true: FMRFamide-like immunoreactivity is not suppressed by preincubation with BPP. These results suggest that there are at least two endogenous peptide antigens in the locust nerve cord: one is found in cells of the suboesophageal and thoracic ganglia, and the other is found in cells of the abdominal ganglia.

Pancreatic polypeptide immunoreactivity in rat brain is actually neuropeptide Y

Radioimmunoassay was combined with high pressure liquid chromatography and immunohistochemistry to establish the identity of pancreatic polypeptide-like immunoreactive material in the central nervous system of the rat. Antisera to avian pancreatic polypeptide, bovine pancreatic polypeptide, the invariant amidated carboxyterminal hexapeptide fragment of mammalian pancreatic polypeptides and the structurally related peptide, neuropeptide Y, were used immunocytochemically to localize neurons containing immunoreactive pancreatic polypeptide-like material in rat brain. Adjacent brain sections stained by the indirect immunofluorescent technique and single sections from double-staining experiments demonstrated that identical fibers and perikarya stained for pancreatic polypeptide-like immunoreactive material by antisera directed against each of the four peptides. Characterization of pancreatic polypeptide-like immunoreactive material in chromatographed rat brain extracts by radioimmunoassay using antisera to either neuropeptide Y or the carboxy-terminal portion of the pancreatic polypeptide molecule revealed that the major peak of immunoreactive material, as measured by either assay, appeared to co-elute with synthetic porcine neuropeptide Y. A minor peak of immunoreactive material co-eluting with peptide YY standard was indicated by the neuropeptide Y radioimmunoassay. This was contrasted by data obtained from chromatographic profiles of rat pancreas, which showed that the main immunoreactive peak, as measured by the neuropeptide Y assay, co-eluted with porcine peptide YY, with a minor peak co-eluting with porcine neuropeptide Y. The main peak of immunoreactive material in pancreas, as measured by the pancreatic polypeptide carboxy-terminal radioimmunoassay, eluted considerably earlier than standard peptide YY, neuropeptide Y and bovine pancreatic polypeptide, and is probably identical to rat pancreatic polypeptide. The results of the study showed that pancreatic polypeptide is not present in rat brain but the major peak of immunoreactive pancreatic polypeptide-like material in rat brain is actually neuropeptide Y. A very small amount of peptide YY is also contained in brain. In pancreas peptide YY was present in concentrations much higher than those of neuropeptide Y, but the predominant peptide of the neuropeptide Y/peptide YY/pancreatic polypeptide family appeared to be rat pancreatic polypeptide.

Effect of pancreatic polypeptide on gallbladder filling

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 underwent laparotomy with placement of catheters into the gallbladder and common bile duct. The gallbladder was perfused with [ 14C]polyethyleneglycol ([ 14C]PEG)-labeled lactated Ringer's solution (LR) at 0.1 ml/min. Effluent from the common bile duct was collected at 5-min intervals during 30-min intravenous infusions of LR, LR + 2% serum albumin, and LR + 2% serum albumin + bovine PP (10 and 50 ng/kg/min). Gallbladder pressure was continuously recorded. Total and incremental fillings were calculated based on volume and [ 14C]PEG concentration changes. Infusion of PP, 50 ng/kg/min, induced significant gallbladder filling. The filling response was progressive and peaked during the final 10 min of peptide infusion. These findings coupled with the observation that serum PP levels are increased for up to 6 hr postprandially suggest that PP may play an important role in the regulation of interdigestive gallbladder filling.

The distribution of bovine pancreatic polypeptide/FMRFamide‐like immunoreactivity in the ventral nervous system of the locust

The distribution of bovine pancreatic polypeptide (BPP) FMRFamide-like immunoreactivity is described in the ganglia of the ventral nerve cord and in the peripheral median nervous system of the locust, Schistocerca gregaria. Immunoreactive cell bodies occur in three regions of the thoracic ganglia: 1) two pairs of cells lie in the anterior of the ganglion ventral to the root of nerve 1 and the anterior ventral association centre; 2) a group of cells lies in the ventral midline at the level at which nerves 3 and 4 leave the ganglion; 3) and two bilaterally symmetrical, posterior lateral groups lie between nerves 5 and 6 at the edge of the ganglion. Immunoreactive cell bodies in the suboesophageal and abdominal ganglia are confined to the midline and are distributed along the anterior-posterior axis both dorsally and ventrally. The processes of the posterior lateral groups have been traced into the neurohaemal organs of the median nerve and beyond. In the periphery such processes innervate the salivary glands and various muscles. The nature of the endogenous antigen contained in the immunoreactive cells has been investigated with the use of antisera against other peptides of the pancreatic polypeptide family, namely avian pancreatic polypeptide, neuropeptide Y, and peptide YY. In addition, BPP antisera not specific for the C terminal hexapeptide have been tested. Liquid preabsorption experiments with BPP and FMRFamide (the molluscan cardioacceleratory peptide) suggest that the endogenous peptide antigen contained in the stained neurones may belong to the pancreatic polypeptide family or to the FMRFamide family.

Histological and immunohistochemical studies of the Segi's cap, a large aggregation of endocrine cells on the intestinal villi of porcine fetuses and neonates.

Segi's cap, a large aggregation of endocrine cells on the top of intestinal villi, was studied in porcine fetuses and neonates by histological and immunohistochemical methods. The following observations were made: 1) Segi's caps were found in the proximal small intestine in all fetuses larger than 17 cm (beyond 10 weeks of gestation), in neonates before suckling and in 1-4 day-old piglets (suckling neonates); they were not found in a 1 week-old animal. 2) Segi's caps were seen more frequently in the distal duodenum and proximal jejunum than in the proximal and middle duodenum. 3) The Segi's cap consisted mainly of numerous argyrophil cells as demonstrated by Grimelius' method and a few argentaffin cells as identified by a modified Masson-Hamperl's method. 4) Immunohistochemically, ten kinds of immunoreactive cells were dispersed in the mucosal epithelium, outside of Segi's caps, in the proximal small intestine of fetuses: 5-hydroxytryptamine (5-HT)-, gastrin-, bovine pancreatic polypeptide (BPP)-, secretin-, somatostatin-, cholecystokinin-, gastric inhibitory polypeptide (GIP)-, motilin-, leucine-enkephalin- and neurotensin-immunoreactive cells. Except for neurotensin-immunoreactive cells, all of these cells were detected also in the caps. 5) Regional differences were noted in the distribution of cells in the caps; gastrin-, BPP- and secretin-immunoreactive cells were dominant in the caps in the proximal duodenum, while 5-HT-immunoreactive cells were most numerous in those in the proximal jejunum.

Pancreatic polypeptides affect luteinizing and growth hormone secretion in rats

We have examined the effects of third cerebroventricular (3V) injections of avian and bovine pancreatic polypeptide (APP and BPP) and the C-terminal hexapeptide amide of human PP (CHPP) on the secretion of anterior pituitary hormones in conscious ovariectomized rats. Injection of APP (2.0 μg; 472 pmoles) or BPP (5.0 μg; 1191 pmoles) decreased plasma levels of luteinizing hormone (LH) when compared to pre-injection levels in these animals or to saline-injected controls. The lower dose of BPP (0.5 μg; 119 pmoles) decreased plasma LH versus pre-injection levels and control animals, however, these effects diminshed at later times. Plasma growth hormone (GH) also decreased following 3V injections of APP (2.0 μg) or BPP (5.0 μg). The lower dose of BPP (0.5 μg) initially inhibited GH release, however, this effect was rapidly reversed and GH levels were significantly greater than those in controls at 60 and 120 min. Injections of BPP or APP did not alter prolactin (PRL) or thyroid stimulating hormone (TSH) secretion. Administration of 2.0 μg and 0.2 μg of CHPP (2488 and 249 pmoles) produced no significant effects on plasma LH, GH, PRL or TSH. APP and BPP had no consistent effects on hormone secretion from dispersed anterior pituitary cells. The results indicate that APP and BPP exert potent central effects which inhibit LH and GH release from the pituitary gland.

Neuropeptides in a microturbellarian-Whole mount immunocytochemistry

A whole mount immunofluorescence method was used for the localization of immunoreactivity (IR) to four regulatory peptides and the bioamine serotonin in the nervous system of Stenostomum leucops (Turbellaria, Platyhelminthes). The flatworm S. leucops belongs to the taxon Catenulida which, according to the new phylogenetic system by Ax [2], forms a key group between the coelenterates and more advanced flatworm species. Positive IR was obtained using antisera against FMRF-amide, β-endorphin, growth hormone releasing factor (GRF), substance P, and serotonin. The distribution patterns of these neuropeptide-like immunoreactivities differ significantly from each other. Antisera against Leu-enkephalin, bovine pancreatic polypeptide (BPP), bombesin, cholecystokinin (CCK-8), neurotensin, somatostatin, growth hormone (GH), secretin, and neurophysin II gave negative results. This primitive flatworm shows similarities with hydra in the lack of IR to anti-somatostatin, anti-Leu-enkephalin, and anti-BPP. These antisera give positive IR in more advanced flatworm species, indicating a later convergent evolution of vertebrate-like peptides within the phylum Platyhelminthes.

Gastric and enteral pancreatic polypeptide (PP) immunoreactivity in the dog

Extrapancreatic pancreatic polypeptide (PP) was quantified by determination of PP-cell density using antibodies to human PP (hPP) and bovine PP (bPP) in stomach, duodenum, jejunum, ileum, and colon of the dog. Further, these organs of 3 beagles were extracted and subjected to radioimmunoassay again using 2 different antisera (one directed against bPP, the other against hPP). Purification of these extracts were performed by Sephadex chromatography. We found bPP immunoreactive cells in stomach, small and large bowel, but hPP immunoreactive cells, besides in the pancreas, only in stomach and duodenum, thus demonstrating heterogeneity of extrapancreatic PP. Extraction and chromatography confirm the presence of PP immunoreactivity in the pancreas, stomach, small and large intestine. The observation of a postprandial rise of serum PP levels in a man with total duodenopancreatectomy suggests that the extrapancreatic PP cell may release PP.

Sensitive radioimmunoassay for measurement of circulating peptide YY

A radioimmunoassay with sufficient sensitivity to detect the recently discovered, circulating peptide YY in the majority of healthy adults has been developed. The antiserum to synthetic peptide YY raised in rabbits essentially showed no cross-reactivity with bovine or porcine synthetic pancreatic polypeptide, neurotensin, or neuropeptide Y, but cross-reacted to the extent of 0.03% with synthetic peptide HI. The minimum detectable limit of the assay for plasma peptide YY was 20 pg/ml with coefficients of variation < 16%. The immunoreactivity of peptide YY isolated from healthy adult plasma had a gel-filtration chromatographic profile similar to that of synthetic peptide YY. Fasting levels of peptide YY in plasma from 127 of 137 (92.7%) ostensibly healthy adults were measurable and showed a log-normal distribution. Using the maximum-likelihood estimation method, we calculated the normal range to be 13–178 pg/ml with a geometric mean value of 49 pg/ml. The fasting plasma peptide YY levels showed no significant age or sex dependency.

Comparative immunohistochemical and biochemical analysis of pancreatic polypeptide-like peptides with special reference to presence of neuropeptide Y in central and peripheral neurons

Antisera raised against porcine neuropeptide Y (NPY) and peptide YY (PYY) were characterized with regard to immunohistochemical staining, cross-reactivity to several pancreatic polypeptide (PP)-related peptides, and radioimmunoassayable tissue levels in the rat and pig. The NPY antiserum (102B) reacted with nerves in many areas of both the central and peripheral nervous systems, but it did not stain endocrine cells of the pancreas or intestine. No evidence for any cross-reactivity of the NPY antiserum with related peptides of the PP family, such as avian PP, bovine PP, PYY, gamma-MSH, FMRF-amide, or avian PP (31-36), was obtained. The NPY antiserum was N-terminally directed, and regional levels of NPY as seen by radioimmunoassay paralleled well the occurrence of NPY-immunoreactive structures seen in the immunohistochemical study. High pressure liquid chromatography analysis revealed that the NPY-immunoreactive material from cerebral cortex and vas deferens had elution profiles similar to those of standard porcine NPY. The PYY antiserum mainly stained endocrine cells in the pancreas and intestine as well as a small neuron system in the brainstem of the rat. Although this antiserum had a slight cross-reactivity to NPY in radioimmunoassay, the neuronal PYY staining was separate from that of NPY. High levels of PYY were found in the intestine, and levels above the threshold were also seen in the dorsal vagal complex of the rat. The other antisera investigated (raised against avian PP, bovine PP, gamma-MSH, and FMRF-amide) caused neuronal staining that was abolished by preabsorption with NPY. This was also seen even if no detectable cross-reactivity with NPY was found in radioimmunoassay. These latter antisera also stained endocrine cells in the pancreas and intestine with complex cross-reactivity relationships, suggesting the presence of intestinal PP-like peptides in addition to PYY and NPY.

Immunohistochemical studies on glucagon, glicentin and pancreatic polypeptide in human stomach: normal and pathological conditions.

Endocrine-like cells containing glucagon, glicentin or pancreatic polypeptide immunoreactivity in human foetal and adult stomach, with or without disease, were studied with the indirect immunoperoxidase method and mirror sectioning technique. In foetal and neonatal oxyntic mucosae, there were endocrine-like cells with glucagon and glicentin immunoreactivities and argyrophilia. Cells containing glicentin immunoreactivity alone were detected earlier than glucagon cells during foetal development, and were also distributed throughout foetal to neonatal life. Bovine pancreatic polypeptide immunoreactivity coexisted in a subpopulation of the glucagon-glicentin cells. These cells were absent from normal oxyntic mucosa in the postneonatal period and from normal antral mucosa throughout life. Hamartomatous polyp in adult oxyntic mucosa, hyperplastic oxyntic mucosa in Menetrier's disease and atrophic oxyntic mucosa in a remnant stomach with cancer showed scattered glucagon-glicentin cells, but few or no cells containing bovine pancreatic polypeptide. Intestinalized mucosa showed plentiful glicentin cells with occasional glucagon and/or bovine pancreatic polypeptide immunoreactivity. Some gastric cancer cells of both diffuse and adenoplastic types contained immunoreactive glicentin and, less frequently, glucagon. Bovine pancreatic polypeptide immunoreactivity was detected in a few adenoplastic cancer cells, but not in diffuse type cells. Three different anti-pancreatic polypeptide sera against bovine, porcine or human pancreatic polypeptide detected basically the same cells mentioned above, but pancreatic polypeptide cells lacking human pancreatic polypeptide immunoreactivity were also present in foetal oxyntic mucosa. Immunoabsorption tests revealed that the bovine pancreatic polypeptide immunoreactivity was remote from peptide YY and neuropeptide Y.

VIP inhibition of vascular smooth muscle: complementary to beta 2-adrenoceptor mediated relaxation in the isolated rat portal vein.

Exogenous VIP caused a concentration dependent inhibition of the spontaneous mechanical activity in the isolated rat mesenteric-portal vein preparation via a mechanism which was completely independent of the propranolol-blocked beta-adrenoceptor, of high K+ in the medium and of exogenous bovine pancreatic polypeptide, neurotensin and opioids. The potency of VIP (pD2 = 7.52 +/- 0.18, n = 6) was about 30 times higher than that of isoprenaline in the atropine and phentolamine-blocked preparation. The isoprenaline inhibition was mediated via a beta 2-type of adrenoceptor with low apparent affinity for noradrenaline (intrinsic activity (alpha) = 0.27 +/- 0.01, n = 8). Opposite effects of exogenous VIP and noradrenaline were on the other hand observed in the atropinized and beta-blocked preparation. These results suggest that in the rat portal vein neuronal VIP and circulating adrenaline may be complementary in their antagonism of the alpha-adrenoceptor mediated increase in contractility.

Immunocytochemical demonstration of a homology in peptidergic neurosecretory cells in the suboesophageal ganglion of a beetle and a locust with antisera to bovine pancreatic polypeptide, FMRFamide, vasopressin and α-MSH

In the suboesophageal ganglion of the Colorado potato beetle and the migratory locust three types of peptidergic neurosecretory cells were identified immunocytochemically with antisera to bovine pancreatic polypeptide, FMRFamide, vasopressin and α-MSH. Their locations and immunocytochemical reactions are similar, which suggests that these peptidergic cells in both insect species are homologous and perhaps have similar functions.

Pancreatic polypeptide from rat pancreas.

Pancreatic polypeptide (PP) has been isolated from rat pancreas by gel filtration, ion exchange chromatography, and high performance liquid chromatography. The isolation was monitored with a RIA, using antibody to the carboxyl-terminal hexapeptide of bovine PP. Rat PP contains 36 amino acids and is similar in composition to PP from other mammalian sources. The single methionine residue in the peptide appears to oxidize easily to the sulfoxide, thereby giving rise to two immunoactive peaks on high performance liquid chromatography. Reduction to the native peptide can be accomplished with mercaptoethanol. The PP content of rat pancreas is about 2 mg/kg. The amino acid sequence of rat PP is Ala-Pro-Leu-Glu-Pro-Met-Tyr-Pro-Gly-Asp- Tyr-Ala-Thr-His-Glu-Gln-Arg-Ala-Gln-Tyr-Glu-Thr-Gln-Leu-Arg-Arg-Tyr-Ile- Asn-Thr-Leu-Thr-Arg-Pro-Arg-Tyr-NH2. This sequence preserves characteristics necessary for stabilization of the compact globular conformation found in avian PP.

Immunocytochemical localization of neurons in the nervous system of the Colorado potato beetle with antisera against FMRFamide and bovine pancreatic polypeptide.

Particular neurons in the nervous system of the Colorado potato beetle, Leptinotarsa decemlineata, are recognized by antisera against bovine pancreatic polypeptide and FMRFamide. Both antisera react with the same neurons. Solid phase absorptions showed that antiserum against bovine pancreatic polypeptide cross-reacts with FMRFamide, whereas antiserum against FMRFamide cross-reacts with bovine pancreatic polypeptide. Some of the immunoreactive neurons have axons branching extensively within the neuropile, which suggests that the peptide is used as transmitter. In the corpus cardiacum, a neurohaemal organ in insects, numerous immunoreactive axon terminals are present. Here, the peptide material is presumably released as a hormone.

&lt;b&gt;IMMUNOCYTOCHEMICAL INVESTIGATION OF POLYPEPTIDE YY (PYY) AND PANCREATIC POLYPEPTIDE (PP) IN THE GASTROINTESTINAL TRACT OF THREE &lt;/b&gt;&lt;b&gt;RODENTS &lt;/b&gt;

The gastrointestinal tract of three rodents (the mouse, hamster and guinea pig) was investigated immunocytochemically using antisera raised against porcine polypeptide YY (PYY), bovine pancreatic polypeptide (BPP) and the C-terminus (sequence 24-36) of BPP. PYY-Immunoreactive cells were found in the alimentary tract of the three species studied. Neither BPP- nor BPP C-terminus-immunoreactive cells were detected in any parts of the digestive tract of these species. PYY-Immunoreactive cells were observed in the colon and caecum of the three species investigated and in the rectum of the mouse and guinea pig. These cells were seen also in the pylorus, duodenum and ileum of the mouse. PYY-Immunoreactive cells in the three rodents studied were of the open type, i.e. they extended from the basal lamina to the gut lumen. In the mouse colon these cells were found to extend a cytoplasmic process from the basal part towards the neighbouring cells.

A critical examination of the occurrence of FMRFamide immunoreactivity in the brain of guinea pig and rat

Several reports (cf. Weber et al. (1981) Science 214:1248-1251) have described the extensive occurrence, in rat brain, of material immunologically related to the molluscan neuropeptide FMRFamide. We have reexamined these data in guinea pig and rat, using six different antisera to FMRFamide. Immunoreactive perikarya and fibres were found to be distributed throughout the rodent brain (Table 1). This distribution was roughly similar to that found by Weber and coworkers. However, solid-phase absorption of the antisera with bovine pancreatic polypeptide, which shares an arginine and an amidated aromatic amino acid (RYamide) with FMRFamide, showed that staining in most regions could be due to crossreactivity with bovine pancreatic polypeptide-like (or neuropeptide Y-like) material. Double-labelling experiments with antisera to FMRFamide and bovine pancreatic polypeptide led to the same conclusion. The only structures where no apparent crossreactivity occurred were perikarya and fibres in the nucleus dorsomedialis, ventromedialis, periventricularis and paraventricularis hypothalami and fibres in the area lateralis hypothalami, nucleus parabrachialis, substantia grisea centralis mesencephali, various parts of the formatio reticularis, and spinal cord. Hence only these structures might contain material which is more related to the molluscan tetrapeptide.