Norepinephrine enhances radiosensitivity in rat ileal epithelial cells.

Area of Science:

• Radiation biology
• Gastroenterology
• Neuroendocrinology

Background:

• Spontaneously hypertensive rats exhibit higher jejunal crypt cell apoptosis post-X irradiation compared to Wistar-Kyoto rats.
• Sympathetic dysfunction, induced by reserpine, suppressed apoptosis in jejunal crypt cells of both rat strains.
• The study investigates the role of sympathetic nervous system hyperfunction in radiation-induced apoptosis susceptibility.

Purpose of the Study:

• To determine if sympathetic nervous system hyperfunction contributes to the heightened susceptibility of jejunal crypt cells to radiation-induced apoptosis.
• To examine the effect of norepinephrine (NE) on the survival of rat ileal epithelial cells (IEC-18) after X-ray irradiation.

Main Methods:

• Colony formation assay was used to assess cell survival.
• Rat ileal epithelial cells (IEC-18) were subjected to X-ray irradiation.
• The effect of 1 µM norepinephrine (NE) on cell survival and apoptosis was evaluated.

Main Results:

• The addition of 1 µM NE significantly decreased the surviving fraction of irradiated IEC-18 cells from 37% to 8% (at 6 Gy).
• NE enhanced the radiosensitivity of IEC-18 cells.
• Irradiation combined with NE treatment led to an increased cellular apoptotic rate.

Conclusions:

• Norepinephrine enhances the radiosensitivity of rat ileal epithelial cells.
• NE may be a contributing factor to the aggravation of acute radiation injury in the intestine.