Abstract
In this thesis I address some of the possible causes for oligozoospermia
and low sperm motility, two factors that, singly or in combination, are
often seen in cases of male subfertility.
In the first study we evaluated the effect on human spermatozoa of the
toxicity of compounds present in diesel exhaust. The compounds tested
were derivatives of 2-nitrofluorene, and some of them were found to
drastically lower the motility of human spermatozoa. We concluded that
human spermatozoa may be a working model system for testing potentially
toxic compounds.
Sperm Activating Protein is a complex of immunoglobulin G4 and
apolipoprotein A-I, previously shown to be a major extracellular factor
that increases sperm motility. In the second study we determined the
exact identity of the components. In addition we were able, using
selective proteolytic digestion and Western blot, to demonstrate that the
apolipoprotein A-I is bound in the Fab-portion of the immunoglobulin G4.
Oligozoospermia is an other common abnormality seen in male subfertile
patients, and can be due to defects in cell division. In the third study
we focused on the synaptonemal complex, which is a structure that takes
part in the joining of homologous chromosomes during meiosis. The
structure is almost universally conserved in eucaryotic species, and
controls the number and distribution of cross-overs and converts these
into chiasmata. In this work we found that the synaptonemal complex
protein 1 is present in all testicular biopsies from patients with a
partial or fully functional spermatogenesis.
