The effect of halogenated amphetamines on protein synthesis in newborn rats

Abstract

The effects of p-chloroamphetamine and fenfluramine on protein synthesis in newborn rats was studied. Proteins from brain and limb muscles were analyzed by acrylamide SDS gel electrophoresis. Several major proteins detected by this procedure showed a reduced synthesis, induced by the drugs. The most noted effect was in a 34,000 dalton (34K)polypeptide that is more abundant in muscle than in brain. This polypeptide, as well as the adjacent 32,000 dalton (32K) polypeptide, is probably plasma membrane associated. However the synthesis of only one of these two polypeptides is affected by the halogenated amphetamines. Tropomyosin is similar in size to the 34K polypeptide, therefore a possible identity between these two proteins was investigated. A small difference in size, and a distinct pattern of the peptides resulting from these proteins, by partial digestion, excluded such identity. Additionally, an effect of a single dose of those drugs on the development of the newborn rats was noted. A dose of 10–20 mg/kg p-chloroamphetamine or fenfluramine cause a significant retardation in weight gain within three days after the treatment. Treated animals are unable to overcome this induced difference in weight even during the following four weeks. The possibility of similar effects in humans is discussed.