Guinea pig Hageman factor as a vascular permeability enhancement factor

Area of Science:

• Biochemistry
• Hematology
• Physiology

Background:

• Hageman factor (HF) is a key component of the intrinsic coagulation pathway.
• Understanding HF's properties and functions is crucial for hemostasis and inflammation research.
• Guinea pigs serve as a model organism for studying various physiological processes.

Purpose of the Study:

• To purify and characterize guinea pig Hageman factor.
• To investigate the vascular permeability-inducing activity of purified Hageman factor and its active form.
• To compare the potency of active Hageman factor with bradykinin as a vascular permeability factor.

Main Methods:

• Purification of Hageman factor from guinea pig plasma using column chromatography.
• Characterization of purified Hageman factor by SDS-PAGE and gel filtration.
• Assay of clotting time correction activity, vascular permeability induction in vivo, and enzyme inhibition.

Main Results:

• Homogeneous single-chain guinea pig Hageman factor (MW 76,000 Da) was purified, with amino acid composition similar to other species.
• Purified Hageman factor and plasma corrected clotting time in deficient plasma and showed potent vascular permeability-enhancing activity (beta-HFa form).
• The active form (beta-HFa) was significantly more potent than bradykinin and its activity was inhibited by diisopropylfluorophosphate.

Conclusions:

• Guinea pig Hageman factor shares biochemical similarities with Hageman factor from other species.
• Active Hageman factor (beta-HFa) is a highly potent endogenous vascular permeability factor in guinea pigs.
• This finding suggests a significant role for Hageman factor in inflammatory responses involving vascular permeability changes.