Pulmonary function in rats dying from long-term parenteral nutrition

Area of Science:

• Physiology
• Toxicology
• Nutrition Science

Background:

• Parenteral nutrition (PN) is crucial for patients unable to receive nutrition orally.
• Previous studies indicated Vamin (amino acid solution) and Intralipid (fat emulsion) infusions can be fatal in rats.
• Morphological changes observed include vascular injury and thrombus formation in the lungs.

Purpose of the Study:

• To investigate lung function changes in rats prior to death induced by continuous PN.
• To assess pulmonary arterial pressure, endothelial function, and capillary filtration coefficient.
• To evaluate the impact of Vamin-Glukos and Intralipid on lung physiology.

Main Methods:

• Rats were intravenously infused with saline (control), Vamin-Glukos, or Intralipid.
• Infusions were stopped upon signs of deterioration.
• Isolated saline-perfused rat lungs were used to measure pulmonary arterial pressure (Ppa), transpulmonary pressure (Ptp), serotonin inactivation (endothelial function), and capillary filtration coefficient (CFC).

Main Results:

• Vamin-Glukos and Intralipid groups showed central thrombus formation, anemia, and thrombocytopenia.
• Pulmonary arterial pressure (Ppa) significantly increased in Vamin-Glukos and Intralipid groups compared to controls.
• Serotonin inactivation was markedly reduced, indicating impaired endothelial function, and CFC increased in PN groups.

Conclusions:

• Infusion of Vamin-Glukos and Intralipid leads to significant pulmonary hypertension in rats.
• These PN substrates severely reduce pulmonary endothelial function.
• The findings suggest PN substrates can induce critical lung dysfunction preceding death.