Spectrum effects of a new polypeptide (third hormone?) isolated from the chicken pancreas

Hazelwood, Robert L.; Turner, Stewart D.; Kimmel, Joe R.; Pollock, H.G.

doi:10.1016/0016-6480(73)90109-3

Cited by 109 publications

(22 citation statements)

References 16 publications

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“…This brain region, implicated in the central control of gastrointestinal function, is also a site of Y4 expression in mammals (Larsen & Kristensen 2000). The existence of Y4 mRNA in the gut is consistent with the reported stimulation of gastric secretion by pancreatic polypeptide from the proventriculus in the chicken (Hazelwood et al 1973); this was the site in which the strongest gastrointestinal expression of Y4 was observed. Cells immunoreactive for pancreatic polypeptide and PYY (El-Salhy et al 1982) have been observed in the chicken gut, consistent with a role for these peptides in mediating the effects of Y4 on gastrointestinal function.…”

Section: Discussionsupporting

confidence: 68%

“…This may be related to the fact that, in contrast to its action in mammals, insulin is not antilipolytic in birds (Langslow & Hales 1969), and pancreatic polypeptide appears to have taken over this function. In the chicken liver, pancreatic polypeptide has been reported to mobilise glycogen (Hazelwood et al 1973). The effects of pancreatic polypeptide on the spleen and oviduct have not been studied in birds, although the presence of Y4 mRNA in these organs is suggestive of a role for the receptor in mediating erythropoietic/immune and smooth muscle functions respectively.…”

Section: Discussionmentioning

confidence: 99%

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Chicken neuropeptide Y-family receptor Y4: a receptor with equal affinity for pancreatic polypeptide, neuropeptide Y and peptide YY

Lundell

Boswell²,

Larhammar³

2002

Journal of Molecular Endocrinology

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Within the neuropeptide Y (NPY) family of peptides, pancreatic polypeptide is the most divergent across species. It differs in 20 of 36 positions between human and chicken. In mammals, it binds primarily to the Y4 receptor, to which NPY and peptide YY (PYY) bind with lower affinities. Because of these large sequence differences in pancreatic polypeptide, we decided to characterise the chicken Y4 receptor. We report here that Y4 displays the least sequence conservation among the Y-family receptors, with only 57-60% overall amino acid identity between chicken and mammals, compared with 64-83% for the Y1, Y2 and Y5 receptors. After expression of the chicken Y4 receptor in COS-7 cells, I-pPYY, chicken pancreatic polypeptide bound with high affinity at 140 pM. Interestingly, chicken PYY bound with even greater affinity at 68 pM. The affinity of NPY, 160 pM, was similar to that of pancreatic polypeptide. Chicken Y4 is less sensitive than is mammalian Y4 to truncation of the amino terminus of the NPY molecule. RT-PCR revealed expression in several peripheral organs, including adipose tissue and oviduct. In brain, Y4 mRNA was detected in the brainstem, cerebellum and hippocampus. In situ hybridisation to brain sections showed expression in the dorsal motor nucleus of the vagus in the brainstem. Thus the chicken Y4 receptor is less selective and anatomically more widespread than that in mammals, probably reflecting the original properties of the Y4 receptor.

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Section: Discussionsupporting

confidence: 68%

Section: Discussionmentioning

confidence: 99%

Chicken neuropeptide Y-family receptor Y4: a receptor with equal affinity for pancreatic polypeptide, neuropeptide Y and peptide YY

Lundell

Boswell²,

Larhammar³

2002

Journal of Molecular Endocrinology

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“…PP was discovered in 1973 (37,38) and its localization to a specific endocrine cell type in the pancreas was described in 1974-1976 (39-41). The PP release in response to food is under vagal cholinergic control (42)(43)(44)(45).…”

Section: Discussionmentioning

confidence: 99%

Proghrelin peptides: Desacyl ghrelin is a powerful inhibitor of acylated ghrelin, likely to impair physiological effects of acyl ghrelin but not of obestatin

Kumar

Salehi

Rehfeld

et al. 2010

Regulatory Peptides

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Background. Proghrelin, produced by the ghrelin (A-like) cells of the gastric mucosa, gives rise to cleavage products, including desacyl ghrelin, acyl ghrelin and obestatin. The products are thought to be secreted concomitantly. In an earlier study we found acyl ghrelin and obestatin, but not desacyl ghrelin, to suppress the release of hormones from isolated islets of mouse and rat pancreas.Results. Using isolated mouse pancreatic islets to study the suppression of the spontaneous secretion of pancreatic polypeptide (PP) by acyl ghrelin and obestatin, we determined the EC 50 values for the two peptides. For acyl ghrelin it was 2 x 10 -13 M (ranging from 1.7 to 2.8 x 10 -13 M), for obestatin it was 10 -13 M (ranging from 0.3 to 1.1 x 10 -13 M). The Hill coefficient (i.e. the midpoint slope) for the acyl ghrelin dose-response curve was 0.30 (ranging from 0.21 to 0.35); the corresponding value for obestatin was 0.35 (ranging from 0.21 to 0.35). The PP-releasing effect of acyl ghrelin, but not that of obestatin, was counteracted by desacyl ghrelin. The acyl ghrelin dose-response curve was shifted to the right in a parallel manner by increasing concentrations of desacyl ghrelin. A Schild plot was constructed with a slope of 0.78, giving an apparent pA 2 value of 14.Conclusions. The results favour the view that acyl ghrelin and obestatin suppress spontaneous PP secretion at physiologically relevant concentrations and that they act on separate receptors. However, we conclude also that desacyl ghrelin acts as a competitive, surmountable (and quite potent) inhibitor of acyl ghrelin. In view of the allegedly high circulating concentrations of desacyl ghrelin it is to be expected that the effect of acyl ghrelin -but not that of obestatin -will be impaired, in fact probably severely blunted by desacyl ghrelin, thereby compromising the functional significance of circulating acyl ghrelin. In addition, we suggest that isolated pancreatic islets are well suited for studies of receptors to acyl ghrelin and obestatin, and that suppression of PP secretion represents a convenient way to measure the effect of both these peptides.

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“…So far, the physiological role of the "pancreatic polypeptide" is poorly understood, but recent evidence suggests that it is a hormone-like substance regulating the functions of the exocrine pancreas, the liver, the gallbladder, as well as of the gastric mucosa [11,12,13,26,27,28]. Nothing is known as yet about its possible importance in the physiopathology of diabetes, but an important hint is the observation of Floyd and Fajans [29] of increased plasma-levels of HPP in juvenile diabetics.…”

Section: Discussionmentioning

confidence: 99%

Hyperplasia of “pancreatic polypeptide”-cells in the pancreas of juvenile diabetics

1977

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Spectrum effects of a new polypeptide (third hormone?) isolated from the chicken pancreas

Cited by 109 publications

References 16 publications

Chicken neuropeptide Y-family receptor Y4: a receptor with equal affinity for pancreatic polypeptide, neuropeptide Y and peptide YY

Chicken neuropeptide Y-family receptor Y4: a receptor with equal affinity for pancreatic polypeptide, neuropeptide Y and peptide YY

Proghrelin peptides: Desacyl ghrelin is a powerful inhibitor of acylated ghrelin, likely to impair physiological effects of acyl ghrelin but not of obestatin

Hyperplasia of “pancreatic polypeptide”-cells in the pancreas of juvenile diabetics

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