TO THE AGE-DEPENDENCE OF THE COLLAGENEOUS STRUCTURES OF THE HUMAN HEART

Polarization-microscopical measurements combined with silver-staining methods and morphometrical estimations (countings) were used to study the collagen fiber structures of the fibrosa of human atrioventricular valves as well as of the chordae tendineae of the right and left hear t with regard to age and sex differences. Measurements and countings w ere performed on histological sections of the tricuspid valve, bicuspi d valve and the chordae tendineae from a total of 87 subjects of both sexes, who were divided into three age groups (lst and 2nd, 3rd to 5th and > 6th decade) with six to seven persons in each group. Difference s were found between the right and left atrioventricular valve and ana logously between the chordae tendineae of the right and left heart in middle-aged persons with regard to the frequency-distribution H(Q) of the quotients of path differences and the proportion of silver stained collagen fibers as compared to unstained. These differences can be in terpreted as an expression of different functional load (low-pressure vs. high-pressure system). Under higher pressure, the proportion of un silvered fibers with a higher mean value of quotient (mainly assigned to type I collagen) at the expense of the silvered fibers (classified as type III collagen) becomes greater.