A Double Isotope Technique to Determine Regional Albumin Permeability: Effects of Anesthesia

Abstract

The transvascular leakage of albumin in various organs and tissues was studied with a double isotope technique in rats anesthetized with sodium pentobarbital, given intraperitoneally or intravenously, and in unanesthetized (conscious) rats. 125I-labeled albumin and 131I-labeled albumin were injected into the tail vein 1 hr apart. The albumin permeability index in tissues and organs is indicated by the local ratio (Xa/Ya)/(Xb/Yb), where (Xa/Ya) is the ratio of 125I/131I-albumin activities per g of tissue and (Xb/Yb) is the ratio of 125I/131I-albumin activities per g of blood. If there is no passage of albumin across the capillary membrane over the 1-hr period of study, the permeability index will be equal to one. In unanesthetized rats, the liver, lung, kidney, femoral muscle, and femoral skin were regions with a high albumin permeability index (above 2). In these organs, intraperitoneal and intravenous anesthesia caused a decrease or no significant change of the albumin permeability index. There was no significant albumin leakage over 1-hr period (index not significantly different from 1) in the mesentery, abdominal muscle, abdominal skin, cremaster, heart, and brain of unanesthetized rats. Intraperitoneal anesthesia caused the albumin permeability index to increase to approximately 4 in the mesentery, abdominal muscle, and the abdominal skin, but not in the cremaster, heart, or brain. These results demonstrate that pentobarbital anesthesia when given into the peritoneal cavity causes a significant increase in albumin leakage in the abdominal region.

Regional transcapillary albumin exchange in rodent endotoxaemia: effects of fluid resuscitation and inhibition of nitric oxide synthase

“…In non-FR groups, PI A values in control lung, heart, liver and kidney showed close agreement with previously reported values for non-septic rodents [12]. In the present study higher values in skin (14.5 compared with 2.0) and skeletal muscle (7.0 compared with 2.0) may be due to indirect effects of higher doses of sodium pentobarbitone (60 mg\kg compared with 35 mg\kg, intraperitoneal) on the circulation, or the possibility of a low-grade systemic inflammatory response due to surgical cannulation and mechanical ventilation.…”

Highly suggestive preliminary evidence that the renal interstitium contracts in vivo

“…sodium pentobarbital on peritoneal capillaries (Simchon et al. ). Because the time courses of the HT and [Pr]p were independent of the studied group, it is believed that these two variables had no influence on the evolution of the ΔRIHP responses (Series 2 & 3) or on the evolution of the %ΔRoMBF responses (Series 3) to rmDIVE throughout the experiment.…”

Changes in plasma protein extravasation in rat skin during inflammatory challenges evaluated by microdialysis

“…The reduction had little impact on our measurements and was more likely explained by the four times removal of 100 -200 l blood samples followed by dilution of blood as a 0.9% NaCl solution was injected to replace the collected volume. Alternatively, it could be a result of the anesthesia because it previously has been shown that pentobarbital sodium could increase the leakage of albumin from plasma (38). The albumin concentration in plasma at 20 and 30 min was fairly stable with small variation between individuals (49 Ϯ 2 mg/ml).…”