An electron microscopic study of collagen fibril structure after lithium treatment--I. The effect of different lithium doses on mouse skin collagen.

The structure of mouse skin collagen fibrils after treatment with lithium chloride at doses of 1.5 and 6 meq/kg of body weight was studied by electron microscopy. Animals were sacrificed 1 day, 1, 2 and 6 months after the end of a 30 consecutive days experimental period. With the first dose, which is commonly used clinically, although there were areas with normal collagen fibrils there were also regions where the characteristic parallel packing of fibrils was lost completely or it was preserved for a part of the area. With high doses, in most regions the normal packing of fibrils was replaced by an anarchic arrangement. In both cases, collagen fibrils had a marked decrease in mean diameter and showed a higher degree of variability in width and shape than collagen fibrils from controls. Also, many clusters of abnormal fibrils were found with a diameter of up to 260 nm vs 109 nm and a highly irregular outline when viewed in cross-sections. The periodicity D as well as the banding pattern were normal.