Indocyanine Green Alters Transepithelial Electrical Parameters of the Distal Colon

Abstract

Indocyanine green (ICG) is used as a dye marker of the vascular space in gastroenterology, ophthalmology, neurology, and critical care medicine. It is widely regarded to be inert. We report, however, that ICG demonstrates effects on colonic transepithelial electrical parameters which could form a basis for a growing number of deleterious gastrointestinal and other clinical effects. Short-circuit current (Iscc), transepithelial conductance (gt), and transepithelial paracellular flux of 14C-D-mannitol were monitored across sheets of rat distal colon. Dye was introduced to mucosal or serosal tissue surfaces at a concentration similar to that used in vivo (10 microg/ml). ICG decreased Iscc by over 50% and gt by over 10%. Transepithelial mannitol flux was not altered. Dye was effective only from the serosal surface. Cyclic AMP-induced spiking of Iscc was not affected by ICG. Preincubation with amiloride or furosemide did not affect the action of the dye on gt or Iscc. ICG at in vivo dosages is clearly capable of inhibiting ion transport across colon epithelial tissue. The serosal site of action indicates activity on a basal-lateral transport system or diffusion into the cell only across the basal-lateral membrane followed by inhibition of a transporter from the intracellular side. ICG should not be considered inert in vivo. Leakage of ICG from the vascular space into the interstitial fluid space will likely result in tissue morbidity.

Myosin Light Chain Kinase Inhibition: Correction of Increased Intestinal Epithelial Permeability In Vitro

“…TEER values were within the range of previous reports for mouse (32), for rat (33), for human (34), and for Caco-2 (35). There was a significant reduction in TEER following addition of 8μM cD in rat colonic mucosae compared to vehicle controls, which was significantly attenuated by pre-treatment with 50μM ML-9 (Fig.…”

Neurotoxic effects of indocyanine green -cerebellar granule cell culture viability study

“…However, if contained within the vascular space, ICG would very likely be with limited biological effect. Any use of ICG outside the vascular space should be carefully considered, and any condition that would allow for significant leak of ICG into an interstitial fluid space becomes a possible contraindication to its use [74].…”

Mechanisms of Intravitreal Toxicity of Indocyanine Green Dye

“…Similar signs of ICG-induced apoptosis were found in other tissues such as colon and leukemia cancer cells. 74 Increase of bax and abatement of bcl-XL expression indicating apoptosis have been found in human leukemia cells exposed to ICG plus diode laser stimulation. Future studies should elucidate the clinical relevance of ICG-induced cellular apoptosis in the functional outcomes of macular surgery.…”