The immunoelectronmicroscopic localization of human platelet factor 4 in tissue mast cells

An immunoperoxidase method has been developed for staining heparin in the granules of mast cells. The method employs human platelet factor 4 (or anti-heparin) and a rabbit antiserum to this polypeptide. Platelet factor 4 binds to mast cell heparin and provides the basis for immunoperoxidase staining using the rabbit antiserum. Preliminary studies of mast cells in various tissues indicate that the stain is quite specific for the content of mast cell granules, presumably heparin and possibly other glycosaminoglycans.

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Human platelet factor 4 and tissue mast cells

Thrombosis Research ◽

10.1016/0049-3848(80)90431-4 ◽

1980 ◽

Vol 19 (1-2) ◽

pp. 293-297 ◽

Cited By ~ 34

Author(s):

Kathryn M. McLaren ◽

Linda Holloway ◽

Duncan S. Pepper

Keyword(s):

Mast Cells ◽

Human Platelet ◽

Platelet Factor 4 ◽

Platelet Factor

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Half-Life of Platelet Factor 4 (PF-4) in Plasma and Platelets from Macaca Mulatta

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649203 ◽

1977 ◽

Vol 37 (01) ◽

pp. 073-080 ◽

Cited By ~ 5

Author(s):

Knut Gjesdal ◽

Duncan S. Pepper

Keyword(s):

Macaca Mulatta ◽

Half Life ◽

Human Platelet ◽

Gel Filtration ◽

Platelet Factor 4 ◽

Active Protein ◽

Platelet Factor ◽

Membrane Bound

SummaryHuman platelet factor 4 (PF-4) showed a reaction of complete identity with PF-4 from Macaca mulatta when tested against rabbit anti-human-PF-4. Such immunoglobulin was used for quantitative precipitation of in vivo labelled PF-4 in monkey serum. The results suggest that the active protein had an intra-platelet half-life of about 21 hours. In vitro 125I-labelled human PF-4 was injected intravenously into two monkeys and isolated by immuno-precipita-tion from platelet-poor plasma and from platelets disrupted after gel-filtration. Plasma PF-4 was found to have a half-life of 7 to 11 hours. Some of the labelled PF-4 was associated with platelets and this fraction had a rapid initial disappearance rate and a subsequent half-life close to that of plasma PF-4. The results are compatible with the hypothesis that granular PF-4 belongs to a separate compartment, whereas membrane-bound PF-4 and plasma PF-4 may interchange.

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Complete Covalent Structure of Human Platelet Factor 4

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657071 ◽

1979 ◽

Vol 42 (05) ◽

pp. 1652-1660 ◽

Cited By ~ 4

Author(s):

Francis J Morgan ◽

Geoffrey S Begg ◽

Colin N Chesterman

Keyword(s):

Amino Acids ◽

Molecular Weight ◽

Amino Acid ◽

Amino Acid Sequence ◽

Human Platelet ◽

Platelet Factor 4 ◽

Platelet Factor ◽

Disulphide Bonds ◽

Covalent Structure

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.

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Human Platelet Factor 4 (PF 4) Disappearance in Rabbits Fed an Atherogenic Diet

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661467 ◽

1986 ◽

Vol 55 (01) ◽

pp. 146-146 ◽

Cited By ~ 1

Author(s):

Marco Prosdocimi ◽

Alberto Zatta ◽

Fabrizio Fabris ◽

Giuseppe Cella

Keyword(s):

Human Platelet ◽

Atherogenic Diet ◽

Platelet Factor 4 ◽

Platelet Factor

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Clearance and In Vivo Release by Heparin of Human Platelet Factor 4 (PF4) in the Rabbit

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661162 ◽

1984 ◽

Vol 52 (02) ◽

pp. 157-159 ◽

Cited By ~ 5

Author(s):

M Prosdocimi ◽

N Scattolo ◽

A Zatta ◽

F Fabris ◽

F Stevanato ◽

...

Keyword(s):

Half Life ◽

Human Platelet ◽

Slow Component ◽

Platelet Factor 4 ◽

Platelet Factor ◽

In Vivo Release ◽

Partial Release ◽

Different Doses ◽

New Zealand Rabbits

Summary13 male New Zealand rabbits were injected with two different doses (25 μg/Kg and 100 μg/Kg) of human platelet factor 4 antigen (PF4). The disappearance of the protein was extremely fast with an half-life for the fast component of 1.07 ± 0.16 and 1.76 ± 0.11 min respectively. The half-life for the slow component, detectable only with the highest dosage, was 18.8 min.The administration of 2500 I.U. of heparin 30 min after PF4 administration induced a partial release of the injected protein and its clearance from plasma was slow, with half-life of 23.3 ± 5.9 min and 30.9 ± 2.19 min respectively.

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