The occurrence of an unusual tubular organelle in surface epithelial cells of the mouse ascending colon after injection of diazo-oxo-norleucine.

Tubular structures were observed in surface epithelial cells of mice that had been injected with high dosages of diazo-oxo-norleucine (DON), a glutamine antagonist. The tubules often occurred in bundles which contained a variable number of tubules, often as many as one hundren being present. Within the bundles, the tubules were oriented either randomly or parallel to one another. They measured 25 to 35 nm in diameter with angular or circular profiles and were as long as 1 to 2 micron. In the center of each tubule, a smaller tubule-like component was evident that measured 5 to 7 nm in diameter. With the exception of endoplasmic reticulum, often with attached ribosomes, organelles were excluded from the bundles. Since the tubules and the endoplasmic reticulum occasionally were observed to be continuous, it is suggested that the tubules may originate from this organelle.