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Biomedical subjects

A Thorpe

Publications and source records attributed to A Thorpe.

At least 73 records · Page 4Linked to original sources
PubMed1982

A neuropeptide of the blowfly Calliphora vomitoria with an amino acid composition homologous with vertebrae pancreatic polypeptide.

A neuropeptide purified from the brain of the blowfly (Calliphora vomitoria) that cross-reacts in a bovine pancreatic polypeptide radioimmunoassay has been subjected to amino acid analysis. The amino acid composition of the peptide shows homology with vertebrate pancreatic polypeptide species. Amounts of the neuropeptide calculated from amino acid analysis record with those measured by the pancreatic polypeptide radioimmunoassay. These results suggest that the primary structure of the Calliphora neuropeptide is very similar to that of mammalian pancreatic polypeptides.

Amino Acids↗
PubMed1982

The distribution of pancreatic polypeptide in the nervous system and gut of the blowfly, Calliphora vomitoria (Diptera).

The distribution of a neuropeptide, previously shown to have the same or a very similar amino acid composition as vertebrae pancreatic polypeptide (PP), has been studied in the nervous system gut of the blowfly, Calliphora vomitoria. Neurones immunoreactive to a bovine PP antiserum occur in the thoracic and abdominal ganglionic components of the central nervous system, in addition to the brain and suboesophageal ganglion. Pancreatic polypeptide appears to be relayed from its cells of origin to a neurohaemal organ in the dorsal sheath of the thoracic ganglion. PP immunoreactivity is also found in cells of the hypocerebral ganglion of the stomatogastric nervous system and in associated nerve fibres. The mid-gut contains PP-positive material in flask-shaped cells of its epithelial lining.

Animals↗
PubMed1981

Isolation and partial characterization of pancreatic polypeptide-like material in the brain of the blowfly Calliphora vomitoria.

Using 10(6) flies (5 kg of heads) a pancreatic polypeptide-like material has been partially purified from the blowfly Calliphora vomitoria. The isolated material was eluted on Sephadex G-50 similarly to bovine pancreatic polypeptide and had an RF on polyacrylamide-gel electrophoresis that was identical with that of the bovine hormone. The material diluted linearly and showed parallelism with bovine standards in a bovine pancreatic polypeptide immunoassay. In specificity controls the immunoreactivity was not abolished by trasylol and no cross-reactivity was discerned in assay for glucagon, proangiotensin and cyclic AMP. These data suggest that the pancreatic polypeptide material in the brain of the blowfly has close structural similarity to the mammalian hormone.

Animals↗
PubMed1980

Localisation of pancreatic polypeptide (PP)-like immunoreactive material in neurones of the brain of the blowfly, Calliphora erythrocephala (Diptera).

The brain of the blowfly, Calliphora erythrocephala, has been studied by means of the peroxidase-antiperoxidase immunocytochemical method, with the use of antibodies to bovine pancreatic polypeptide (BPP). A number of immunoreactive neurones have been localised, some corresponding to neurones previously identified tentatively as neurosecretory. This finding is further evidence that biologically active peptides, previously considered to be "vertebrates", also exist in invertebrates. It also supports the concept of their evolutionary origin in nervous tissue.

Animals↗
PubMed1979

Isolation of material displaying insulin-like immunological biological activity from the brain of the blowfly Calliphora vomitoria.

An insulin-like material from the brain of the blowfly Calliphora vomitoria was partially purified by acid alcohol extraction, gel filtration and ion-exchange cellulose chromatography. In addition, the RF value on polyacrylamide-gel electrophoresis was determined. The material was characterized by its ability to cross-react with bovine insulin antibody and by displaying diminished immunoreactivity on dilution. It displaced specifically bound 125I-labelled insulin from rat liver plasma membrane insulin receptors and displayed insulin-like biological activity on the isolated rat fat-cell. Within 30 min of injection into Calliphora, made hypertrehalocaemic and hyperglucaemic as a result of median neurosecretory cell removal, it caused the concentrations of both sugars to return to normal. The hypothesis is put forward that the median neurosecretory cells are the source of the material.

Animals↗