1993 Volume 18 Issue 1 Pages 36-50
The following experiment was undertaken to investigate the distribution and structure of lymphatic capillaries in connective tissue underlying an early DMBA-induced cancer of the tongue using golden hamsters. The left lingual margin was rubbed with a dental cleanser in the control group. In an experilnental group, the left lingual margin was treated likewise and was further treated with a 0.5% 9,10-dimethyl 1, 2-benzanthracene acetate solution for induction of an early tongue cancer. Lymphatic vessels in the tongues of both groups were identified by intravascular injection of Indian ink and impregnation with a silver nitrate solution and by double staining with 5’-nucleotidase-alkaline phosphatase.
In the control group, lymphatic capillaries formed a plexus directly above the muscle layer in submucosal connective tissue. A few lymphatic capillaries were found to extend as cecal lymphatic capillaries from the plexus into connective tissue papillae. In the experimental group, the lymphatic capillaries formed another layer of lymphatic network on the epithelial side in addition to a network directly above the muscle layer of connective tissue underlying the early cancer. Furthermore, the cecal lymphatic capillaries extending from the newly formed lymphatic network appeared more frequently than they did in the control group. These cecal lymphatic capillaries were thick and meandered. This pattern of the distribution and structure of lymphatic capillaries was considered to suggest hypermetabolism at the local site of early cancer formation and cancer proliferation.
The 5’-Nase-ALPase double staining is a simple method for the identification of lymphatic capillaries. This study suggested the feasibility of its application to clinicopathological research.
