Comparative Study in the Growth of Pattern Prepubertal, Pubertal and Adult Visceral Organs of Male and Female Mice

Abstract

This study investigated the growth of various organs in 72 male and female mice using increase in weight as the index of growth. The mice were randomly selected from the offspring of the same breeding stock. They were given food and drinking water ad libitum until they were sacrificed at 3, 6 and 12 weeks of age. At each age, 12 males and 12 females were sacrificed by severing the spinal cord at the atlanto-occipital joint. The live body weight of each mouse was determined. Following death, skeletal muscles (triceps brachii and gastrocnemius muscles) and internal organs (lungs, heart, kidneys, liver and spleen) were dissected and their weights were determined. Humerus and femur were also dissected out from each mouse and their lengths were determined. The muscle mass index (milligram muscle weight per gram body weight) was determined for each muscle. The percentage of body weight contributed by each internal organs was calculated. The study demonstrated that although sex differences were not evident in the weights of these organs at 3 weeks of age, there were sex differences in the weights and growth patterns of muscles, bones and internal organs of male and female mice at 6 weeks and 12 weeks of age. It was suggested that these differences may have arisen from the possible significant influence of sex hormones on the growth and development of these organs in both male and female mice.