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At least 19 recordsLinked to original sources
PubMed1997

Functional characterization of neural and smooth muscle motilin receptors in the chicken proventriculus and ileum.

To characterize the motilin receptors present in the chicken, the effects of chicken motilin (Phe-Val-Pro-Phe-Phe-Thr-Gln-Ser-Asp-Ile-Gln-Lys-Met-Gln-Glu-Lys-Glu-Arg -Asn-Lys-Gly-Gln), Leu13 porcine motilin, canine motilin and three erythromycin derivatives (EMA, EM523, GM611) on the contractility of the chicken gastrointestinal (GI) smooth muscles were investigated in vitro and compared with those in the rabbit duodenum. In the proventriculus longitudinal and circular muscle layers, chicken motilin (3 nM-1 microM) caused an atropine- and a tetrodotoxin-sensitive contraction (EC50 = 39-49 nM), and potentiated the EFS-induced contraction without affecting the responsiveness of acetylcholine. EM523 and GM611 (3-100 microM) contracted the proventriculus longitudinal muscle, and the maximum amplitudes of contraction were about 60% of that induced by chicken motilin. Chicken motilin (0.1 nM-100 nM) also caused contraction of the ileum (EC50 = 7 nM) through direct action on the smooth muscle cells. On the other hand, erythromycin derivatives showed only a weak contractile efficacy (about 20% of the maximum response of chicken motilin) even at high concentrations (10-100 microM). The rank order of potency in the ileum was chicken motilin > canine motilin > or = Leu13 porcine motilin > > GM611 > or = EM523 > or = EMA. GM109 slightly inhibited the ideal contractions induced by Leu13 porcine motilin at 100 microM (pA2 = 3.86). In the rabbit duodenum, chicken motilin was a full agonist with the same intrinsic activity as Leu13 porcine motilin, canine motilin and the erythromycin derivatives. However, the rank order of potency (Leu13 porcine motilin > or = canine motilin > chicken motilin > GM611 > or = EM523 > EMA) was different from that in the chicken ileum. In conclusion, chicken motilin causes an excitatory response in the chicken GI tract through activation of neural (proventriculus) and smooth muscle motilin receptors (ileum). The motilin receptor present in the ileum is different from that demonstrated in the rabbit intestine, because of a different rank order of motilin peptides in producing the contraction, low contracting activity of erythromycin derivatives and low antagonistic efficacy of GM109. Different pharmacological characteristics of the mechanical response induced by motilin peptides and erythromycin derivatives between the proventriculus and the ileum are discussed.

Animals↗
PubMed1991

Hormonal control of avian pancreas by gastrin-releasing peptide from the proventriculus.

Endocrine cells in the acid-secreting part of the avian stomach, the proventriculus, contain two forms of gastrin-releasing peptide (GRP) of 27 and 6 residues, respectively. We have examined the actions of exogenous GRP-27 and GRP-6 and endogenously released GRP in the control of pancreatic secretion in urethan-anesthetized turkeys. Chicken GRP-27 and the structurally related amphibian peptide bombesin were potent stimulants of fluid and protein output from the pancreas (at 6-100 pmol/kg, iv). GRP-6 had no significant effect at doses up to 1,000 times higher. A bombesin antagonist, (CH3)2-CHCO-[D-Ala24]GRP-20--26-NHCH3, inhibited the action of exogenous chicken GRP-27 but did not inhibit intravenous cholecystokinin octapeptide (CCK-8). Distension of the proventriculus with a solution of peptone produced an increase in the flow of pancreatic juice and an increase in protein output, which was not reduced by atropine. The bombesin antagonist produced a reversible inhibition of this response. A CCK-gastrin antagonist, BOC-beta-Ala-Trp-Leu-Asp-O(CH2)2- phenyl(4F), which inhibited the action of exogenous CCK, had no effect on the pancreatic response to exogenous GRP-27 or to distension of the proventriculus with peptone. We suggest that protein-rich solutions in the proventriculus release GRP, which in turn acts directly on the pancreas to stimulate enzyme secretion.

Amino Acid Sequence↗
PubMed2002

Proventriculus-specific cDNAs characterized from the tsetse, Glossina morsitans morsitans.

Peritrophic matrix (peritrophic membrane or PM) is an important structure in the gut of most insects at some stage in their development. It is composed of chitin, proteins and proteoglycans. Multiple roles for the PM ranging from partitioning of digestive enzymes and food to protection of gut epithelial cells from viral and parasitic invasion have been proposed. While most adult members of Diptera have a Type I PM synthesized in response to a blood meal, the medically and agriculturally important vector insect, tsetse has a sleeve-like Type II PM which is constitutively synthesized by cells in the proventriculus (cardia). Using a differential hybridization approach, we have identified three abundant cDNAs from a proventriculus cDNA library of GLOSSINA MORSITANS MORSITANS: GmPro1, GmPro2 and GmPro3. DNA sequence analysis indicates that GmPro1 and GmPro2 share similarities with the peritrophin-15 family of larval PM proteins, while GmPro3 is a member of the serine protease family. Northern analysis indicates that transcripts for all three cDNAs are preferentially expressed in the proventriculus tissue. The expression profile of these genes in response to the presence of trypanosome indicates that transcription of GmPro1 is increased in the presence of parasites (immune sensitive), while the other two are not affected. Western analysis using antibodies developed against the recombinant GmPro2 shows its primary localization in the gut to be within the peritrophic matrix structure. We discuss the molecular characteristics of these proventriculus specific cDNAs and their products as well as their potential role for vector control studies.

Animals↗
PubMed1986

Ultrastructural differentiation of glandular stomach (proventriculus) in chick embryo.

Cytochemical characterization of mucosubstances of chick glanular stomach (proventriculus) changes from 15 days of development to postnatal and adult stages was studied. To corroborate these data cytochemical, ultrastructural and ultracytochemical study of chick embryo proventriculus from 7 to 20 days of development was performed. At the 7th day several layers of undifferentiated cells formed an epithelium which covered the walls of the glandular stomach. Mocosubstances were not found. Between the 9th and 5th day a single layer of cylindrical cells was encountered forming invaginations which originated deep glands. Three types of cells were separated from the above mentioned layer, dark, clear and undifferentiated. The dark cells had organelles which are involved in protein synthesis and the clear ones were rich in mitochondria. Argentaffine cells appeared at 15th day instead mucosubstances formed a thin coat on the epithelium at 9th day which increased at the end of development in the apical cytoplasm and gland cells. These observations demonstrate that proventriculus of chick embryo has ultrastructurally differentiated cells involved with enzymatic and hydrochloric acid secretion after the 9th day. These progressive events are correlated with the digestion process of yolk during embryogenesis. At the end of development the proventriculus has completely organized the glandular layer.

Animals↗
PubMed1992

Development and birthdates of vasoactive intestinal peptide immunoreactive neurons in the chick proventriculus.

To gain insight into the mechanisms regulating expression of transmitter phenotypes in the enteric nervous system, we have studied the development and birthdate of vasoactive intestinal peptide immunoreactive (VIP-IR) myenteric neurons in the chicken proventriculus (secretory portion of the avian stomach) by a combination of immunocytochemistry and radioautography. The appearance and numbers of VIP-IR neurons in whole mounts of the myenteric plexus from chick embryos and chickens were examined. We found that VIP-IR neurons first appeared at embryonic day (E) 5.5-6.5 in the distal part of the proventriculus. At E7.5, VIP-IR neurons were found singly, in pairs, or in small groups, which together with unlabeled cells formed primitive myenteric ganglia. VIP-IR fibers were found within the developing fiber tracts which connected the ganglia. The number of VIP-IR neurons was found to be maximum in the E15.5 embryo and to decline to 68% of maximum in the 4 week old chicken. Birthdate studies were performed by application of either single pulses or cumulative doses of [3H]-thymidine to embryos between E3 and E14. Whole mounts of the myenteric plexus from the proventriculus of these embryos were immunostained for VIP at E10 or E17. The whole mounts were subsequently sectioned and processed for radioautography. We found that VIP-IR myenteric neurons were born between E3 and E10 with a peak at E7. Most cells underwent terminal division between E5 and E9. These data will be useful in determining the time and conditions when cells make decisions about transmitter phenotypes.

Aging↗
PubMed1977

[Development and function of endocrine cells in the proventriculus of the chicken (author's transl)].

An argyrophil endocrine cell type with typical intraepithelial development is seen initially on the 8th day of incubation in the epithelium of the main lumen of the chicken-proventriculus. During the embryonic period, rapid development of these cells can be observed with a quantitative maximum on the 13th day of incubation. At this time increased digestive efficiency is necessary for the chicken embryo with the start of gastric secretion combined with the first swallowing of albumen. There is a subsequent decrease in the number of endocrine cells in the main lumen epithelium, their function in hatched or adult specimens is largely taken over by cells which appear in the epithelium of the glands of the proventriculus on the 16th and later days of incubation. On the 2nd day after hatching the adult distribution pattern of endocrine cells in the proventriculus is attained.

Age Factors↗
PubMed2000

Histochemistry of the cuticle from proventriculus in stingless bee, Melipona quadrifasciata anthidioides (Hymenoptera, Apidae).

Histochemical study of the proventriculus from stingless bee Melipona quadrifasciata anthidioides revealed for the first time the presence of cysteine-rich proteins in the cuticle that covers the bulb of the proventriculus and its associated hair-like process. The presence of tyrosine-rich proteins was observed in the same structure, but not in hair-like projections. The cuticle of the crop and a small portion of the proventriculus contained no acid carbohydrates or fats and small amounts of neutral carbohydrates. These results are discussed in relation to different composition of insect cuticle depending on its different functions.

Alcian Blue↗
PubMed1995

Lectin histochemical study of glycoconjugates in the chick embryo proventriculus.

A lectin histochemical study was performed to investigate the glycoconjugate saccharidic moieties of the lining and glandular epithelium of the chick embryo proventriculus from day 7 to hatching. The sugar residues D-galactose-(beta 1-->3)-N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, alpha/beta-N-acetyl-D-galactosamine and alpha-D-mannose were present at the lining epithelium of the proventriculus from the 7th day onwards; alpha-D-fucosyl residues were never detected. The same sugar residues were detected in the cells of the deep glands from the 7th day; alpha-L-fucose appeared later. The sugar residues appeared in the cells of the superficial glands at different times during the development of the proventriculus. In comparison to that of the deep glands, the secretion of the superficial glands was characterized, by the absence of N-acetylgalactosamine and alpha-D-mannose. From day 20 onwards, the composition of the mucus released by the two types of glands was identical from a qualitative point of view. The histological and histochemical results showed that the superficial glands are well defined morphological structures and not "an artefact of contraction", as claimed by other authors.

Animals↗
PubMedDate not supplied

[The proventriculus of the Xenopsylla cheopis flea studied by scanning electron microscopy].

The proventriculus of the flea X. cheopis was studied by means of scanning electron microscopy. The external surface of the proventriculus is a rigid structure with an alveolate surface ("wasp nest") formed by muscular cords. The internal surface of the proventriculus is represented by numerous acanthae which fall close together. They have a shape of bent dens with longitudinal sharply angular edges and concave spaces between them. Some edges are crenate.

Animals↗
PubMed1991

Immunocytochemical and ultrastructural characterization of endocrine cells in chicken proventriculus.

The endocrine cells of the chicken proventriculus were investigated immunocytochemically, using the peroxidase-antiperoxidase technique on paraffin and semithin sections for light microscopy, and immunogold staining in osmium-fixed material for electron microscopy. The fixation procedure also allowed a detailed ultrastructural investigation. Twenty-three antisera were tested and 7 immunoreactive cell-types were identified: D-cells containing somatostatin-like peptide; EG-cells immunoreactive to anti-glucagon, anti-GLP1 and anti-neurotensin; NT-cells labelled only with anti-neurotensin; BN-cells containing bombesin-like material; ENK-cells showing met-enkephalin immunoreactivity; EC-cells reactive to anti-serotonin; and APP-cells positive to anti-avian pancreatic polypeptide. In addition, enterochromaffin-like (ECL) cells, were also detected by electron microscopy. The presence of ENK-cells and the ultrastructure of these and NT-cells are described for the first time in chicken proventriculus, and glucagon. GLP1 and neurotensin are shown to be colocalized in the EG-cells.

Animals↗
PubMed1979

The avian proventriculus is an abundant source of endocrine cells with bombesin-like immunoreactivity.

Radioimmunoassays using specific bombesin antisera revealed high concentrations of immunoreactivity in the turkey proventriculus, and negligible amounts of activity elsewhere in the gut. In immunohistochemical studies the same antisera revealed abundant endocrine-like cells in proventriculus mucosa, and isolated cells in small intestinal mucosa. In contrast to the rat, immunoreactivity was not demonstrated in nerves.

Animals↗
PubMed2000

The nervous system of the chicken proventriculus: an immunocytochemical and ultrastructural study.

The proventriculus constitutes the glandular region of the chicken stomach. This organ is innervated by two parasympathetic networks, the myenteric and submucous plexus, and here we present a systematic study of this system by immunohistochemistry and electron microscopy. All the neurons and fibres were positive for the neural markers, protein gene product 9.5 and the amidating enzymes. Immunoreactivities for the constitutive neuronal isoform of the enzyme nitric oxide synthase and the vasoactive intestinal peptide were present in neuronal bodies suggesting an intrinsic origin for the similarly immunoreactive fibres found in the proventriculus. On the other hand, immunoreactivity to gastric inhibitory peptide was only found in varicose fibres making contact with the blood vessels and the glandular epithelium, but never in the neuronal somas, suggesting that this substance may be provided by an extrinsic nervous system whose neuronal bodies are located elsewhere. Electron microscopy revealed frequent neuromuscular and neuroepithelial connections in the muscle layers, the wall of the blood vessels and the epithelium. In addition, synapsis-like structures were identified in the proximity of cells belonging to the diffuse endocrine system, providing a new example of neuroendocrine contacts. No positivity was found for antibodies against other neural substances including somatostatin, peptide histidine-isoleucine, peptide tyrosine-tyrosine, neuropeptide tyrosine, bombesin, met-enkephalin, serotonin, substance P, galanin, calcitonin gene-related peptide and S-100 protein.

Animals↗
PubMed1990

Arginine vasotocin and mesotocin in the anterior hypothalamus, neurohypophysis, proventriculus and plasma of White Leghorn cockerels, during dehydration.

1. The effect of 96 hrs of water deprivation on plasma electrolytes, osmolarity, arginine vasotocin (AVT), mesotocin (MT), and on AVT and MT content in the neurohypophysis, anterior hypothalamic area (AHA) and proventriculus, was studied at 24 hrs intervals, in adult White Leghorn cockerels. 2. Plasma AVT increased three fold during the first 24 hrs but there was no further change during the next 48 hrs. In the last 24 hrs, plasma AVT decreased in about 25%. Plasma MT did not change during the entire period of dehydration. 3. Plasma sodium and osmolarity gradually increased during that time. 4. Neurohypophysial AVT content was depleted by 95% during the period of dehydration while MT content did not change. 5. In the AHA there was no change in AVT levels during dehydration while the levels of MT increased while in the proventriculus there was no change in either AVT or MT levels. 6. For the data collected during the entire experimental period, no correlation was found between plasma osmolarity and plasma AVT, but there was a highly significant negative correlation between plasma osmolarity and neurohypophysial AVT content. 7. It may be suggested that the depletion in AVT content in the neurohypophysis during progressive water deprivation resulted in an insufficient level of AVT in circulation to enable the cockerels to counter the dehydration. This may explain the death of those cockerels which were dehydrated for a further 24 hr period.

Animals↗
PubMed1988

Gizzerosine raises the intracellular cyclic adenosine-3',5'-monophosphate level in isolated chicken proventriculus.

Gizzerosine, which was originally found in fish meal, is a compound that causes gizzard erosion and ulceration in chicks. The action of gizzerosine on the isolated cells of chicken proventriculus was studied in the present investigations. Gizzerosine increased intracellular cyclic adenosine-3',5'-monophosphate (cAMP) levels, reaching a plateau within 30 min. Similar maxima of cAMP level were observed in the presence of histamine or gizzerosine. However, the potency of gizzerosine was approximately 1,000-fold higher than that of histamine. The action of gizzerosine was depressed by cimetidine, a histamine H2-receptor antagonist, but not by pyrilamine, a histamine H1-receptor antagonist, indicating that gizzerosine is a very strong histamine H2-receptor agonist. The mucosal cells isolated from the proventriculus by the present procedure had both histamine H1 and H2-receptors. Gizzerosine showed a higher affinity to the cell surface histamine receptor than histamine. These results partly explain the potent activity of gizzerosine in inducing gastric acid secretion and causing gizzard erosion and ulceration in chickens.

Animals↗
PubMedDate not supplied

Cryptosporidium sp. infection in the proventriculus of an Australian diamond firetail finch (Staganoplura bella: Passeriformes, Estrildidae).

An Australian diamond firetail finch died following the acute onset and development of severe diarrhea. The bird was purchased from a wholesaler and was housed in a pet store aviary with 12 other birds. Necropsy, histologic evaluation, and electron microscopic evaluation revealed organisms in the proventriculus (surface, ductal, and glandular epithelium) compatible in site of development, size, and morphology with Cryptosporidium spp. Lesions in the proventriculus were focal cuboidal metaplasia of glandular epithelial cells and deposition of amyloid in the perivascular interstitial tissues at the base of the glands. Amyloid also was present in the duodenum, liver, spleen, pancreas, and kidney. Inability to recover other organisms suggested that Cryptosporidium was the primary cause of diarrhea and death. The affected bird likely suffered dehydration as a result of acute gastrointestinal disturbance, concomitant with renal amyloidosis and urate nephrosis.

Animals↗
PubMed1975

Demonstration of acid phosphatase activity in the proventriculus of common weaver bird, Ploceus philippinus and whitebreasted kingfisher, Halcyon smyrnensis.

Acid phosphatase activity was histochemically localized in the proventriculus of two birds namely Ploceus philippinus and Halcyon smyrnensis. It was found that acid phosphatase-rich lysosomal activity appears to be relatively better developed in the proventriculus of piscivorous form, H. smyrnensis than that of granivorous form. P. philippinus. Simultaneously, a possible correlationship between the variable lysosomal activity and specific food diets of the birds has been discussed.

Acid Phosphatase↗
PubMed2002

Refinement of wingless expression by a wingless- and notch-responsive homeodomain protein, defective proventriculus.

Pattern formation during animal development is often induced by extracellular signaling molecules, known as morphogens, which are secreted from localized sources. During wing development in Drosophila, Wingless (Wg) is activated by Notch signaling along the dorsal-ventral boundary of the wing imaginal disc and acts as a morphogen to organize gene expression and cell growth. Expression of wg is restricted to a narrow stripe by Wg itself, repressing its own expression in adjacent cells. This refinement of wg expression is essential for specification of the wing margin. Here, we show that a homeodomain protein, Defective proventriculus (Dve), mediates the refinement of wg expression in both the wing disc and embryonic proventriculus, where dve expression requires Wg signaling. Our results provide evidence for a feedback mechanism that establishes the wg-expressing domain through the action of a Wg-induced gene product.

Animals↗