Comparative analysis of body weight gain in laboratory animals with different routes of administration of Lcarnitine

In recent years, several studies have been published that suggest that L-carnitine supplementation may affect weight in some animal species and humans, and may also affect the body composition of growing animals. Currently, only a few results are available on the effects of L-carnitine on weight loss and body composition in animals. Therefore, the purpose of this study was to find out whether injections of L-carnitine can influence the dynamics of the weight of laboratory animals. Toxicity studies were conducted on outbred rats in October 2021 in the vivarium of the St. Petersburg State University of Veterinary Medicine. The study involved females weighing 190-210 grams, purchased from the Federal State Unitary Enterprise “Nursery of Laboratory Animals “RAPPOLOVO”. When studying subchronic toxicity after subcutaneous and intramuscular administration, L-carnitine was administered at 2 dose levels. Doses were determined based on the results of the acute toxicity experiment: 1/5 and 1/10 of the maximum tolerated dose. The first experimental group (n=10) received the drug intramuscularly at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg). The second experimental group (n=10) received the drug intramuscularly at a dose of 0.04 mg/kg (1/10 of 2000 mg/kg). The third experimental group received subcutaneous L -carnitine at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg), the fourth experimental group received subcutaneous L-carnitine at a dose of 1/10 of the maximum tolerated (2000 mg/kg body weight). Group 5 was the control group (n=10) and received sodium chloride 0.09% intramuscularly at a dose of 1/5 of 2000 mg/kg, group 6 was the control group and received sodium chloride 0.09% subcutaneously at a dose of 1/5 of 2000 mg /kg. As a result of studies of subchronic toxicity on laboratory animals of the drug L-carnitine for veterinary use with subcutaneous and intramuscular administration, it was established that a dosage of 1/5 of the maximum tolerated, and a dosage of 1/10 of the maximum tolerated, does not cause changes in the dynamics of body weight animals.