title: Association of lactate, intracellular pH, and intracellular calcium during capacitation and acrosome reaction: contribution of hamster sperm dihydrolipoamide dehydrogenase, the E3 subunit of pyruvate dehydrogenase complex.
abstract: The role of dihydrolipoamide dehydrogenase (DLD), the E3 subunit of the  pyruvate dehydrogenase complex (PDHc) in hamster sperm capacitation and  acrosome reaction has been implicated previously. In this study, attempt has  been made to understand DLD/PDHc involvement from the perspective of  pyruvate/lactate metabolism. Inhibition of DLD was achieved by the use of a  specific inhibitor, 5-methoxyindole-2-carboxylic acid. It was seen that  5-methoxyindole-2-carboxylic acid-treated spermatozoa with inhibited DLD  (and PDHc) activity had lactate accumulation, which caused an initial lowering  of the intracellular pH and calcium and an eventual block in capacitation and  acrosome reaction. Collectively, the data reveal a significant contribution of  the metabolic enzymes DLD and PDHc to lactate regulation in hamster  spermatozoa during capacitation and acrosome reaction. Additionally, the  importance of lactate regulation in the maintenance of sperm intracellular pH  and calcium, two important physiologic factors essential for sperm  capacitation and acrosome reaction, has also been established.
authors: Centre for Cellular and Molecular Biology, Uppal Rd, Hyderabad 500 007, India.
authors: S
authors: S
authors: Panneerdoss
authors: A B
authors: AB
authors: Siva
authors: D B
authors: DB
authors: Kameshwari
authors: N
authors: N
authors: Rangaraj
authors: S
authors: S
authors: Shivaji
mesh_terms: D020101:Acrosome Reaction / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D006224:Cricetinae; D008058:Dihydrolipoamide Dehydrogenase / Q000037:antagonists & inhibitors / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000494:pharmacology; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D008647:Mesocricetus; D013075:Sperm Capacitation / Q000502:physiology*; D013094:Spermatozoa / Q000187:drug effects / Q000201:enzymology*
chemical_list: D007211:Indoles; C008400:5-methoxyindole-2-carboxylic acid; D019344:Lactic Acid; D008058:Dihydrolipoamide Dehydrogenase; D002118:Calcium