Excess ROS
may be a cause of your IUI failure: ROS are usually washed away with
semen preparation in IUI
/ART: Reactive oxygen species are metabolites of oxygen and include A) superoxide
anion, B) hydrogen peroxide, C) hydroxyl
radical and D) nitric oxide.
ROS is
produced by both spermatozoa and leucocytes. Increased number of sperms would produce
more ROS. When present in excess they can initiate oxidative damage
to cellular lipids, proteins and DNA.
Fortunately
most cells are equipped with enzymatic or non enzymatic antioxidant systems. The seminal plasma also has
these enzymes. Now coming to sperm preparation , while preparing sperms,
seminal plasma is removed and the sperms are rendered vulnerable to oxidative
attack affecting sperm function.
Tests can
differentiate ROS produced from sperms and those from leucocytes. Chemiluminescent
procedures employing probes such as luminal or lucigenin may be used to measure
ROS production.
What
is peroxidase staining?? Ans: The ejaculate contains cells, other than spermatozoa,
referred to as round cells. These include germinal line
cells sloughed cells from seminiferous tubules, epithelial cells from genitourinary
tract, prostate cells, spermatogenic cells and leukocytes. A normal ejaculate should not
contain more than 1 x 10 6 round cells/ml. The number of leucocytes
should not exceed 1 x 10 6.
The concentration of granulocytes in
semen can be determined using peroxidase staining and hemocytometer counts.
Round cells
that lack polymorphonuclear morphology may be 1) immature germinal cells (spermatocytes,
spermatids) 2) exfoliated epithelial cells. These may be degenerating and
difficult to identify. To identify them special staining procedures with
monoclonal antibodies are used. If round cells are more than 1 million it
should be ascertained whether they are leucocytes or spermatids, as leucocytes
more than 1 million indicate an infection which may affect fertility. Although
CASA system can be used to automatically measure sperm concentration, errors
are encountered when there are high and low concentrations, significant
agglutinates or large amount of significant debris. The manual count can be
obtained with a coefficient of variation of less than 10%.
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