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The effects of intra-arterially administered histamine on vascular permeability
Insights
Intra-arterial histamine administration reduced dye excretion across the articular barrier in cats, despite increased blood flow. This suggests histamine influences joint barrier permeability.
Area of Science:
- Physiology
- Pharmacology
- Biochemistry
Background:
- The articular barrier, comprising the synovial membrane and vascular endothelium, regulates substance passage into joints.
- Understanding factors influencing articular barrier permeability is crucial for joint health and disease research.
Purpose of the Study:
- To investigate the effect of intra-arterially administered histamine on articular barrier permeability in a feline model.
- To determine if histamine alters the passage of substances from blood to synovial fluid.
Main Methods:
- Cats were used to study the influence of histamine on articular barrier permeability.
- Histamine was infused into one knee joint's circumflex femoral artery branch.
- Dye penetration from blood through the articular barrier was assessed by perfusing knee joints with saline and measuring dye content colorimetrically.
- Local blood supply was monitored using thermoelectric methods.
Main Results:
- Intra-arterial histamine administration significantly reduced dye excretion into the perfusate of the infused knee joint.
- This reduction in permeability occurred despite a marked improvement in local blood supply on the histamine-infused side.
- The findings indicate a direct effect of histamine on the articular barrier's permeability.
Conclusions:
- Histamine, when administered intra-arterially, decreases the permeability of the articular barrier (synovial membrane and vascular endothelium).
- The observed decrease in permeability is independent of, and occurs in conjunction with, enhanced local blood supply.
- These findings have implications for understanding inflammatory joint conditions where histamine may play a role.
Abstract:
The influence of intra-arterially administered histamine on the permeability of the articular barrier (synovial membrane plus vascular endothelium) was studied in cats. The dye penetration from the blood through the barrier was tested by perfusing the two knee joints with saline; the histamine solution was infused through one of the circumflex branches of the femoral artery. The dye content of the two perfusates was measured colorimetrically, the local blood supply of the two knee joints thermo-electrically. In the great majority of experiments it was found that the dye excretion was considerably reduced on the histamine-infused side, in spite of marked improvement of blood supply.