Changes of organ indices of CBA/Ca inbred mice as function of age.

Weight changes of seven organs: brain, heart, lungs, liver, spleen, small intestine, and kidneys, were analyzed during aging of male CBA/Ca inbred mice. Data were collected as absolute organ weights, organ weights related to body, as well as brain weights. It was established that most organs increase their weight up to nearly two years of age, after which there is a dramatic decline. Body weight shows a distinct plateau or constancy along the lifespan of the animals; consequently, body weight seems to be generally the most favorable reference point to express some of the physiological changes and parameters of the aging organism. Variation coefficients of the organ weights generally become higher with age.