Relationship between fascicle size and perineurial collagen IV content in diabetic and control human peripheral nerve

Aim: The relationship between perineurial collagen IV content and fascicle size was determined in diabetic and control human peripheral nerve. Methods and results: Age-matched diabetic and control sural nerve samples w ere immunostained using antibodies to collagen IV. The number of cell layer s and the perimeter of the fascicle were measured and the collagen IV conte nt of the perineurium determined. Using this method, a comparison could be made of collagen IV content in the perineuria of fascicles of different siz e. A positive linear relationship was found between fascicle size and the a mount of collagen IV per unit of perineurium. The number of perineurial cel l layers and the collagen IV content of the diabetic nerve did not differ f rom control values. Conclusions: The linear relationship between fascicle size and perineurial collagen IV content per unit of perineurium underlines the importance of ta king fascicle size into account when determining changes in basement membra ne components associated with neuropathy. The results indicate that increas ed deposition of collagen IV is not involved in the early changes in the pe rineurial cell basement membrane and is thus not the primary factor involve d in altered nerve function associated with diabetic neuropathy.