Ultrastructural studies on horse ligaments : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biophysics at Massey University

Abstract

This thesis has been devoted to studying one of the largest structural units present in most connective tissues - the collagen fibriL Diameter distributions of collagen fibrils from horse ligaments have been investigated as a function of age. A fairly complete age-related study of collagen fibril diameter distribution was targeted during this work. The ligaments (lateral collateral ligament, medial collateral ligament, radioscaphoid ligament, lateral pisoformometacarpal ligament and scaphocapitate ligament) were sampled from horses of ages one year, two-and-half year, five year, six year and eleven year. Electron microscopy methods were employed and corresponding electron micrographs were obtained from transverse sections. These were used to calculate a mean diameter and mass-average diameter of the collagen fibrils. Individual histograms were plotted showing the frequency and mass distribution of the fibrils versus the diameter at each of the ages studied. The data obtained have been related to the mechanical properties of the ligaments and their mode of growth. The diameter distributions obtained clearly reflect the mechanical needs of the ligaments during various stages of maturation. Results from a previous study of these ligaments at one particular age (four years) have been compared and found to be compatible with the results obtained during the course of this study. The effect of training on collagen fibril diameter distribution of horse ligaments has also been discussed.