RESUMO
The biochemical characteristics of human seminal plasma and the possible role of these parameters in relation to infertility problems were the aim of this study. In the present work semen samples were collected from 64 males attending the infertility Clinic and Family Planing Unit of Mansoura University Hospital, for problems concerning infertility and fertility regulation. Semen samples were subdivided into normo, astheno, oligoastheno and azoospermic groups according to the recommendation of the European Androlgy Club 1970. The seminal plasma samples were analysed for total plasma proteins, immunoglobulins IgG, IgA and IgM, fractionation of peptides and the trace metals Zn, Cu, Mn and Pb. It has been concluded from the present work that the essential trace elements, zinc, copper and manganese are always present in seminal plasma, zinc may be positivly correlated with spermatozoa count and to less extent with motility. Lead which is non-essential metal, and a toxic cumulative environmental pollutant was not detected in semen. The decrease in total seminal plasma proteins observed in azoospermic semen may reflect endocrine imbalance or anatomical abnormality. The peptides-types and concentrations-in the seminal plasma were variable in the different groups of semen. It is of value to call for more detailed studies aiming at identification of chemical nature, and source of these peptides, and to study their effects in spermatozoa metabolism, motility and fertilizing capacity. Immunoglobulins G and A are normaly present in the seminal plasma and may play a role in protection against infections by bacteria or viruses, but under certain abnormal conditions the level of IgG and IgA [in particular] significantly increase either by transudation from blood and/or local production, and an altered immune response may occur leading to auto-antibody in the male against spermatozoa which results in sperm agglutination or immotility. IgM is not present in seminal fluid of both normal and abnormal semen groups as it is a macromolecule and non-diffusible through the blood-prostate barrier