Microscopic Lesions Without Functional Impairment of Striated Musculature of Suckling E-Low Rats. ∗

Abstract

In endeavoring to determine the minimal prophylactic dose of alpha tocopherol which would insure the normality of the cross-striated musculature in suckling young rats, alpha tocopherol dissolved in ethyl laurate was administered at the 6 mg and 10 mg levels by stomach tube to a considerable series of mothers on the first day of lactation. The young were observed daily for evidences of the slightest impairment of gait, capacity to right themselves promptly when placed on their backs, et cetera. Thirty young were thus studied from mothers receiving 6 mg of alpha tocopherol and 41 from mothers receiving 10 mg. Sixty-four young from mothers receiving the solvent alone were also observed; in the last mentioned group all young showed paralyses or evident impairment of muscular function. Virtually all the young from mothers receiving either dose of alpha tocopherol appeared to be perfectly normal in their gait, righting reactions, et cetera.

Histological study of 16 muscles was made in the case of several animals from each of the 3 groups. To our surprise in the case of the 6-mg group, 12 of the 16 muscles examined showed the typical microscopic lesions of dystrophy, although these were not extensive; i.e. plenty of normal musculature remained, a fact in harmony with the complete lack of observable motor impairment of these animals.† In the 10-mg group microscopic lesions were entirely absent from all muscles studied. The muscles examined were diaphragm, gastrocnemius, adductor magnus, semimembranosus, extensor digitorum longus (communis), flexor digitorum profundus, biceps brachii, triceps brachii, psoas major, erector spinae group, sternomastoideus, serratus anterior, acromiotrapezius, pectoralis major, masseter and tongue. The masseter and tongue musculature proved themselves to be the least likely to be affected, the gastrocnemius and sternomastoideus the most likely to be affected.