• Immunocytochemical detection;
  • mitochondrial damage;
  • TCA cycle


There is a possibility that mitochondrial respiration defects may contribute to asthenozoospermia.

Method of study

Immunocytochemical detection was used to localize succinic dehydrogenase (SDH) in the head and mid-piece of spermatozoa by fluorescent microscope.


The study revealed dispersed SDH activity in the semen of asthenozoospermic subjects in comparison with control semen samples. While the stain intensity varied from cell to cell in controls as well as in patients, it was predominantly localized within mid-piece of spermatozoa in healthy individuals. In contrast, in semen of infertile male, the diffused and dispersed SDH immunoreactivity was observed in head as well as in mid-piece region of spermatozoa.


Dispersed expression of mitochondrial SDH in head and mid-piece of spermatozoa of asthenozoospermia subjects indicates mitochondrial damage because of metabolic or genetic factors, affecting energy production and leading to disturbed sperm motility, which could be pathologically significant. Detailed mitochondrial SDH immunolocalization studies are warranted to establish a role of deranged tricarboxylic acid cycle in causation of male infertility.