Prolongation of scrapie incubation period by an injection of dextran sulphate 500 within the month before or after infection.

Abstract

A single intraperitoneal injection of 250 micrograms dextran sulphate 500 (DS500) reduced the susceptibility of mice to scrapie given by the same route. A lower dose (25 micrograms) was less effective but still produced significant incubation period lengthening, while a high dose (2.5 mg) further increased the degree of prolongation. This reduced susceptibility occurred with DS500 administered up to at least 4 weeks prior to intraperitoneal scrapie inoculation and up to at least 2 weeks after scrapie inoculation. A reduced average effect, but more variable between mice, was obtained with DS500 given 1 month or 2 months after scrapie. The effective scrapie titre was reduced by 90% when DS500 was injected either 72 h before or 7 h after ME7 scrapie. Using a relatively lower but normally still fatal dose of the 22A strain of scrapie approximately 50% of the treated mice survived. The effective 90% loss of titre was consistent with either of these strains of scrapie in 11 different inbred strains of mice (BALB/c, BSC, BRVR, C3H, C57BL, IM, LM, MM, RIII, VL and VM). No significant increase in the prolongation effect was obtained using multiple DS500 doses in two different time combinations. DS500 causes long-term interference in both the early processing and the replication of scrapie agent, unlike those immunomodulators which increase susceptibility.

• Authors: C F Farquhar, A G Dickinson
• Journal: The Journal of general virology (J Gen Virol) Vol. 67 ( Pt 3) Pg. 463-73 (Mar 1986) ISSN: 0022-1317 [Print] England
• PMID: 2419489 (Publication Type: Journal Article)

Chemical References

• Dextrans
• Phytohemagglutinins
• Prions
• Dextran Sulfate

Topics

• Animals
• Dextran Sulfate
• Dextrans (administration & dosage, immunology)
• Mice
• Peritoneal Cavity (cytology)
• Phytohemagglutinins (pharmacology)
• Prions (immunology, pathogenicity)
• Scrapie (etiology)
• Time Factors