Morphologic Effects of DDT on Nerve Endings, Neurosomes, and Fiber Types in Voluntary Muscles.

Summary The limited experimental evidence presented in this paper tends to support the statement that DDT increases the discharge of auriphilic neurogenic substances from some motor end plates into the myoplasm of some of the voluntary muscle fibers. These neurogenic substances form massive aggregates of neurosomes in parts of some voluntary muscle fibers. This results in a partial or complete dissociation of the neurogenic from the myogenic substances in the muscle fiber. Auriphilic granules are likewise found at the 2 poles of the elongated nuclei in the dark muscle fibers. The supporting evidence that some of the auriphilic granules and masses found after DDT toxicity are neurogenic in origin follows : (1) anatomical continuity of the auriphilic bodies in muscle with the auriphilic hypolemmal axons of the motor end plates; (2) similarity of staining reaction of the masses in muscle and axons of nerve endings with gold impregnation; (3) massive aggregation of auriphilic bodies in some muscle fibers contemporaneous with the centrifugal depletion of the related nerve axons and endings of their auriphilic substances. Presumptive evidence is presented that the normal fiber types in voluntary muscle are dependent, in part, upon the periodic alternation of the discharge and disappearance, by chemical action, of the neurogenic granules in the same muscle fiber at different time periods. The limited evidence also indicates that DDT poisoning may be produced in normal rats by feeding, and in chameleons by the intraperitoneal injection of the previously perfused, dehydrated, and emulsified muscles of rats manifesting toxicity with DDT.