Heparin transfer across the rabbit peritoneal membrane

Area of Science:

• Nephrology
• Pharmacokinetics
• Biomedical Engineering

Background:

• Heparin is used in peritoneal dialysis to prevent intraperitoneal clotting.
• Heparin's systemic absorption was presumed negligible due to its inability to cross the peritoneal membrane.

Purpose of the Study:

• To investigate the permeability of the peritoneal membrane to heparin.
• To quantify heparin's passage into the bloodstream during experimental peritoneal dialysis.

Main Methods:

• 7 New Zealand white rabbits underwent experimental peritoneal dialysis with 99mTc-labeled heparin.
• Three protocols varied heparin concentration (500-2,500 U/l) and diffusion time (15 min to 3 h).
• Radioactivity in dialysates, blood, organs, and urine was measured.

Main Results:

• Labeled heparin was detected in dialysates, blood, organs, and urine.
• Recovered radioactivity ranged from 1.5% to 20% of the introduced amount.
• Heparin passage was dependent on concentration and diffusion time.

Conclusions:

• Heparin does pass through the peritoneal membrane.
• The extent of heparin absorption is influenced by the dose and duration of exposure.
• Findings challenge the assumption of heparin's inability to cross the peritoneal barrier in peritoneal dialysis.