Protamine sulfate induces enhanced peritoneal permeability to proteins

Area of Science:

• Nephrology
• Biochemistry

Background:

• Peritoneal dialysis (PD) is a crucial renal replacement therapy.
• Understanding factors influencing solute and protein transport in PD is vital for optimizing treatment.
• Anionic sites in the peritoneum are potential regulators of protein passage.

Purpose of the Study:

• To investigate the direct link between the neutralization of anionic sites by intraperitoneal protamine and protein passage during PD.
• To determine the role of anionic sites in limiting transperitoneal protein transfer.

Main Methods:

• Experiments were conducted in rabbits undergoing isosmotic peritoneal dialysis.
• Two 1-hour exchanges were performed: a baseline and an experimental exchange.
• Protamine (50 µg/ml) was administered in the experimental exchange in Group B.
• Protamine (50 µg/ml) and heparin (50 U/ml) were administered in Group C.
• Metabolite and protein concentrations in the peritoneal fluid were measured.

Main Results:

• Protamine administration in Group B significantly increased protein passage (100% increase, p < 0.01) compared to controls.
• Transperitoneal passage of albumin was substantially enhanced by protamine.
• No significant changes in urea, glucose, or uric acid transfer were observed with protamine.
• Heparin neutralization of protamine in Group C prevented the enhanced protein passage.

Conclusions:

• Neutralization of anionic sites by intraperitoneal protamine directly increases protein passage into the peritoneal cavity during PD.
• The availability of anionic sites is a critical limiting factor for transperitoneal protein transfer.
• Protamine does not significantly affect the transfer of small neutral molecules.