Psychopharmacological effect of cyanide ingestion on pregnant rats and their litters

Abstract

Cyanide is responsible for the degenerative effect of certain brain areas responsible for some behavioural outcomes in animals and humans alike. Though cyanide exists generally in the environment, it is also commonly contained in some natural food sources notably, vegetables, fruits, and root crops, like cassava, a staple food in Nigeria and other tropical countries. This study, therefore, investigated the effects of chronic ingestion of cyanide on pregnant rats and their offspring. A total of 60 Wister Albino rats were used in the study. They comprised of 20 female pregnant rats that ingested cyanide and 40 of their offspring that were prenatally exposed to cyanide. The 20 pregnant female rats were randomly assigned into four treatment groups of five rats each. Group 1 was given low dosage cyanide (0.1mg/kg body weight), group 2 was given high dosage cyanide (0.4mg/kg body weight), group 3 received saline, and group 4 received no treatment, while 10 of their offspring were selected from each treatment group from a total population of 103 offspring littered by the pregnant rats. Treatment covered the first 16 days of the gestation period. Dependent variables observed were the psychopharmacological outcomes of cyanide ingestion such as body weight maintenance of the mother rats, infant mortality, Litter size, average birth weight, still birth, malformation, and exploratory learning behaviour of the offspring. The analysis was done using independent group randomized design and tested four hypotheses using one-way analysis of variance and the independent t-test. Results showed that Mother rats that received a high dosage of cyanide gained less weight when compared with Mother rats in other treatment groups (F(316) = 21.18, P<.01). Infant mortality was found to be higher among the offspring of rats that received a high dose of cyanide (F(2.4) = 26.88, P<.05), when compared to offspring of rats that were treated with a low dosage of cyanide. Infant mortality was not observed in either the saline or the "no treatment" groups. Exploratory learning behaviour of offspring of rats prenatally exposed to cyanide was significantly affected (F(3.36) = 14.35, P.001). Offspring of rats prenatally exposed to the high dose of cyanide were slower in learning tasks, ( ̅ = 212.43) than those given low dose of cyanide ( ̅ = 147.54). However, there was no significant effect on the growth of offspring of rats prenatally given cyanide (t = 0.58, df=15, P>.05). It is therefore concluded that chronic ingestion of cyanide by pregnant mother rats has a negative effect on both the mother rats and its Litters, more so during the neonatal period. A recommendation is hereby made to the government for enactment and enforcement of enabling laws and policies aimed at eliminating or reducing the concentration of cyanide in foods as beneficial effects may be observable in human populations.