Physiological responses, organ distribution, and circulation kinetics in anesthetized rats after hypovolemic exchange transfusion with technetium-99m-labeled liposome-encapsulated hemoglobin.

Abstract

Physiological responses and circulation properties of liposome-encapsulated hemoglobin (LEH) labeled with technetium-99m (99mTc) were measured in rats after a 10% (170 mg/kg hemoglobin; 430 mg/kg phospholipid) or a 50% (450 mg/kg hemoglobin, 2.3 g/kg phospholipid) hypovolemic exchange transfusion (n = 5 per exchange group). Mean arterial pressure returned to baseline values (105 +/- 8 mmHg) by 90 min post-infusion for both groups. By 20 h, mean arterial pressure remained at baseline values for the 10% group, but dropped to 30 +/- 14 mmHg for the 50% group. For both groups, bradycardia was seen after the exchange period, but heart rate recovered by 30 min for the 10% group and by 90 min for the 50% group. The 99mTc-LEH remained in circulation longer for the 50% group (18.2 h half-life) than for the 10% group (2.4 h half-life). Removal of 99mTc-LEH from the bloodstream was via the liver and spleen. At 20 h, 99mTc-LEH accumulation in these organs was greater for the 10% group (liver, 36.2 +/- 1.7%; spleen, 37.5 +/- 2.5%) than for the 50% group (liver, 17.0 +/- 1.4%; spleen, 17.1 +/- 1.4%). The data show that there is less clearance of 99mTc-LEH from the bloodstream by the reticuloendothelial system after a 50% hypovolemic exchange transfusion, thus supporting the possible use of LEH as an oxygen-carrying resuscitative fluid in situations of severe blood loss.

• Authors: B Goins, R Klipper, J Sanders, R O Cliff, A S Rudolph, W T Phillips
• Journal: Shock (Augusta, Ga.) (Shock) Vol. 4 Issue 2 Pg. 121-30 (Aug 1995) ISSN: 1073-2322 [Print] United States
• PMID: 7496897 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Anesthetics
• Blood Substitutes
• Drug Carriers
• Hemoglobins
• Liposomes
• Technetium Compounds

Topics

• Anesthetics
• Animals
• Blood Circulation (physiology)
• Blood Substitutes (administration & dosage, pharmacokinetics)
• Drug Carriers
• Exchange Transfusion, Whole Blood
• Hemodynamics (drug effects)
• Hemoglobins (administration & dosage, pharmacokinetics)
• Liposomes
• Male
• Metabolic Clearance Rate
• Mononuclear Phagocyte System (physiopathology)
• Rats
• Rats, Sprague-Dawley
• Shock (therapy)
• Technetium Compounds
• Tissue Distribution (physiology)