The secretion of Pancreatic Polypeptide (PP) is stimulated by meal especially protein and fat. PP is also produced by endocrine active tumours in the pancreas and the gastrointestinal tract. These tumours often produce several peptide hormones in the combinations PP-VIP, PP-glucagon or PP-gastrin. Tumours with only PP-secretion have been reported. These tumours may occur at the WDHA or Verner-Morrison syndrome.
Elevated fasting levels of PP in serum are found at the occurrence of PP-producing tumours and endocrine tumours in the pancreas and in the gastrointestinal tract.
The PP EURIA is a highly sensitive and specific radioimmunoassay kit for the determining PP in human serum.
Intended use
The intended use of these reagents is for assay of PP in human serum.
For professional use within a laboratory.
This product is also available as research use only. Product code: RB 316 RUO
For complete product description, claims and use, please refer to the Instructions For Use. Contact your local representative for availability in your country.
Background
Pancreatic polypeptide (PP) is synthesized as an amino-terminal moiety of a precursor peptide. PP isolated from pancreas has 36 amino acid residues with an amidated C-terminal tyrosine. PP is secreted by F-cells of the islets of Langerhans. PP is localized almost entirely in the pancreas although detectable levels throughout gastrointestinal tract have been reported. PP in human plasma is reported to exist in at least four different forms:
PP 1-36, PP 3-36 and two unidentified forms.
PP is released into plasma during stimulation of meal. The physiological role of PP includes inhibition of stimulated gastric and pancreatic exocrine secretions and augmentation of insulin inhibited hepatic glucose production. These actions of PP are mediated by specific receptors. Receptor binding studies have shown that the intact C-terminal tyrosine amide is necessary for biological activity.
Technical information
PP in serum is assayed without extraction by a competetive radioimmunoassay using a rabbit antiserum raised against bovine PP. PP in standards and samples compete with 125I-labelled human PP in binding to the antibodies. 125I-PP binds in a reverse proportion to the concentration of PP in standards and samples. Antibody-bound 125I-PP is separated from the unbound fraction using the double antibody-polyethyleneglycol precipitation technique. The radioactivity of the precipitates is measured. Human, synthetic PP is used for standardization.
Kit components and storage of reagents
The reagents provided in each kit are sufficient for 100 tubes.
Composition of the reagent kit
1. Anti-PP (Reagent A)
Rabbit antiserum raised against bovine PP. For 100 tubes. Lyophilized in 5.0 mL
0.5M phosphate buffer, pH 7.4, 2.5% human serum albumin and 0.5% NaN3.
Reconstitution in 52 mL distilled water.
2. 125I-PP (Reagent B)
Contains 28 KBq or 0.75 μCi of 125I-hPP at the activity reference date. Produced by iodination of synthetic human PP. HPLC-purified, monoiodinated.
Specific activity: 1700-2100 μCi/nmol (62-77 MBq/nmol).
Lyophilized in 1.25 mL 0.5M phosphate buffer, pH 7.4, 2.5% human serum albumin,
0.5% NaN3. Contains 0.12 mL normal rabbit serum.
Reconstitution in 12.5 mL distilled water.
3. Double antibody-PEG (Reagent C)
50 mL diluted goat anti-rabbit-Ig antiserum. Diluent: 0.05M phosphate buffer, pH 7.4, 0.25% human serum albumin and 0.05% NaN3. Contains 7.5% polyethylene glycol 6000 (w/v).
4. Standard diluent (Reagent D)
10.0 mL PP-free human serum, lyophilized. Contains 500 KIU Trasysol/mL. Reconstitution in 10.0 mL distilled water. For preparation of PP-working standards.
5. PP-standard, 2 000 pmol/L (8370 pg/mL) (Reagent E)
2.00 mL, 2 000 pmol/L synthetic human PP-standard. Lyophilized in 0.05M phosphate buffer, pH 7.4, 0.25% human serum albumin, 0.05% NaN3. Reconstitution in 2.00 mL distilled water.
6. Assay buffer (Reagent F)
5.0 mL 0.05 M phosphate buffer, pH 7.4, 0.25% human serum albumin and 0.05% NaN3.
To be used instead of antiserum in the non-specific binding test tubes.
7. Controls (Reagent G-H)
Lyophilized serum controls with low (G) and high (H) concentration of PP.
1.00 mL of each control after reconstitution. The PP concentrations of the controls are given on the label of the vials. Contains 0.05% NaN3.
Reagent preparation and storage
Store all reagents at 2-8° C before reconstitution and use. The water used for reconstitution of lyophilized reagents should be distilled in an all-glass apparatus or be of corresponding purity. Dissolve the contents in a vial by gentle inversion and avoid foaming. The stability of the reagents is found on the labels of the vials. For lyophilized reagents the expiry dates are valid for the unreconstituted reagents. Reconstituted reagents are stable for 10 weeks (no longer than to the expiry date) stored correctly.
