Abstract

Horseradish peroxidase (HRP) was intravenously injected into guinea-pigs to ultrastructurally examine the permeability of the blood/air barrier. Adults were given 300 mg/kg of the tracer in a small volume of saline, anesthetized and sacrificed at intervals by either intratracheal filling or right ventricular perfusion with 3% glutaraldehyde. The reaction product had passed through endothelial clefts and accumulated in the interstitium as early as 1.5 min after injection. This same degree of penetration occurred with either fixation method used. Tight junctions between pneumocytes prevented passage of the reaction product into alveoli. Pinocytotic vesicles were numerous in both endothelial and epithelial cells, but did not significantly contribute to tracer transport. Ten minutes post-injection was selected as optimal for this model since the highest concentration of tracer was found in the tissues at this time.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.