The role of the imino transporter protein in sepsis-impaired intestinal proline absorption

Everted gut sac model as a tool in pharmaceutical research: limitations and applications

OBJECTIVES

This review discusses the limitations and applications of the everted gut sac model in studying drug absorption, metabolism, and interaction.

KEY FINDINGS

The mechanism of drug absorption, interaction and the effect of factors such as age, sex, species, chronic therapy, and disease state on drug absorption have been summarized. The experimental conditions and their effects on the outcomes of trials have been discussed also.

SUMMARY

The everted sac model is an efficient tool for studying in-vitro drug absorption mechanisms, intestinal metabolism of drugs, role of transporter in drug absorption, and for investigating the role of intestinal enzymes during drug transport through the intestine.

Reduced intestinal absorption of arginine during sepsis

OBJECTIVE

To investigate the effect of sepsis on the intestinal absorption of arginine.

DESIGN

Controlled, nonintervention study.

SETTING

Surgical research laboratories of Sinai Hospital of Baltimore.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

Experimental sepsis induced by cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide.

MEASUREMENTS AND MAIN RESULTS

Sepsis assessed by peritoneal and blood cultures. Intestinal absorption estimated by measuring the transfer of 3H-arginine by everted jejunal sacs prepared from septic and control animals (n = 6 per group) at multiple time points after the induction of sepsis (6, 12, 24, 48, and 72 hrs after cecal ligation and puncture; 6 and 12 hrs after intraperitoneal injection of lipopolysaccharide). Induction of peritonitis in the rat by cecal ligation and puncture significantly reduced the in vitro uptake of arginine by everted jejunal sacs at 12, 24, and 48 hrs after laparotomy. Arginine transfer by everted jejunal sacs was also significantly reduced in rats as early as 6 hrs after intraperitoneal injection of endotoxin (endotoxin 273 +/- 14; saline 377 +/- 14 nmol/sac/hr). Data are expressed as mean +/- SEM. Recovery from sepsis was associated with normalization of arginine transfer by intestinal sacs.

CONCLUSIONS

Experimental sepsis, induced by either cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide, resulted in impaired intestinal amino acid uptake. Impaired intestinal arginine absorption may explain the lack of benefit of enteral, compared with parenteral, arginine therapy on survival from a septic insult.