CONTRIBUTIONS TO THE BIOCHEMISTRY OF BROMINE. I.

Abstract

A number of recent methods for the estimation of bromine in plant and animal tissues have been tested. A combination of the methods of Francis and Harvey (34) and of Yates (98), with some modifications, has been proved capable of yielding controlled and accurate results for amounts of bromine not less than 3 micrograms, in amounts of material of not more than 1 gm.Using the method outlined, material from a large number of marine plants and animals and from typical land plants and animals has been examined for bromine content; in many cases iodine analyses were either already available or have been made on the same material. The results suggest the following conclusions:Bromine is an invariable constituent of marine algae, but no definite relation appears to exist between their bromine and iodine contents. Land plants contain considerably less bromine. Environmental conditions, and perhaps selective affinity by the species and cells in the different parts of the individual plant, probably determine the actual content of bromine.All the marine species of animals examined contain bromine; but in very variable quantity. Environment and selective cell affinity appear to be the controlling factors.The thyroid and blood of the mammals completely examined (rat, rabbit, and dog) contain amounts of bromine slightly higher than those present in other tissues. Ox, sheep and hog thyroids contain similar amounts. Pituitary tissue contains amounts scarcely, if at all, greater than most of the other tissues of the mammalian organism; this last finding is not in agreement with statements by certain other investigators.No relation has been found to exist between the distribution of bromine and iodine in mammalian tissues, and, so far, it is uncertain whether bromine is of functional significance, especially since it does not appear to be particularly associated with the thyroglobulin of the thyroid.