Genetic Variation in Responses to Repeated Administrations of ACTH and Hydrocortisone in Immature Chickens

Abstract

BEFORE one considers the relationships between responses to exogenous ACTH or glucocorticoid administration and responses to environmental stimuli, it is important to consider whether birds from varying genetic backgrounds respond similarly to these exogenous materials.Thiessen and Nealy (1962), using eosinophil count and adrenal weight as response criteria to handling stress, reported that the pattern of response for one of five inbred strains of mice could not be used to predict the pattern for the others. Highly significant differences in changes of plasma corticosterone levels resulting from electric shock treatments were found among four inbred mouse strains by Levine and Treiman (1964).Genetic differences in thiouracil-induced hypothyroidism (El-Ibiary and Shaffner, 1951; Shaklee and Shaffner, 1955), and in assay sensitivity to gonadotropins (Siegel and Siegel, 1964a, b) have been observed; however, little has been reported concerning genetic influences upon the response of the avian pituitary-adrenal cortical system to exogenous hormone stimulation… .