The isolation from spleen tissue of high molecular weight proteins which alter vascular permeability: Investigation of their pharmacological properties

Abstract

A soluble extract from rat spleen, spleen permeability factor (SPF), predominantly protein in content, increases vascular permeability in rat skin by release of histamine and 5-HT from tissue stores. Increase in vascular permeability by SPF is markedly reduced by pretreatment with a combination ofmepyramine and methysergide or by local depletion of skin tissue amines by48/80. SPF releases histamine and 5-HT from rat peritoneal mast cells. This differs from histamine release by antigen, 48/80 and octylamine as it is blocked by 0.1 mM iodoacetic acid and is unaffected by calcium lack or by preheating the cells to 45~ for 5 minutes. There is no detectable kinin release by SPF which is devoid of general proteolytic or TAMe esterolytic activity at neutral pH. Nor does it seem to contain prostaglandins. The possible importance of SPF in the inflammatory response in delayed hypersensitivity reactions is discussed.

Chemical properties of a high molecular weight spleen extract with permeability activity

“…The bioassays were generally carried out in the form of 2 + 2 assays and their statistical evaluation is described in the following paper [4]. The bioassays were generally carried out in the form of 2 + 2 assays and their statistical evaluation is described in the following paper [4].…”

“…The bioassay is described in the preceding paper [4]. The bioassay is described in the preceding paper [4].…”

“…Neither did acetone extraction which might have been expected to remove lipid soluble material such as prostaglandins [17] appreciably reduce the permeability effects of SPF [4]. Our samples of SPF were subjected to dialysis over a wide range of pH without apparent loss of activity.…”

“…The following paper [4] will describe SPF 40/70, an extract from spleen tissue, as containing non-dialysable proteins capable of causing increased vascular permeability in rat skin through the release of histamine and 5-HT.…”