Body weights, absolute and relative organ weights by maturation and ageing (with sexual differences), and their importance as measures of reference for metabolic investigations.

In this contribution, several organs important, especially for geronto-pharmacological not only out of theoretical but especially for practical clinical reasons, to the development of absolute and relative organ weights of rats are examined, as related to a) body weight that is exhibited during the life span, and b) to the weight of the brain. This examination deals with male and female albino rats of the Sprague-Dawley-inbred strain, Sut : SDT ( Chbb : SPF) of both sexes that were two months old at the beginning of the experiment. The experiment results are given in monthly intervals and should be reference figures for metabolism and performance analyses of the examined organs during the course of life into old age (in continuation of corresponding earlier studies, also with humans). Since the following results are obviously of great importance to human medicine, the corresponding age groups for comparison are given and verified. The findings also show that pharmacokinetic experiments in extended test series concerning development during the course of life, therefore concerning all age groups, with the use of the here tested parameters, are better to conduct with female rats than with male. Along with this, the relative organ weights in relation to the brain weight are better to use than the (until now, usual) relative organ weights in relation to body weight. Further shown by the results of these studies is that, during the often necessarily large series, it can be preferable to use the absolute organ weights rather than the relative organ weights (as related to body weight).(ABSTRACT TRUNCATED AT 250 WORDS)