STUDIES OF LACTATE DEHYDROGENASE (LDH) IN THE TESTIS

THE FRACTIONATION OF LACTATE DEHYDROGENASE (LDH) into its isoenzymes

1. Differentiation of the anodic (LDHi and LDH2) and cathodic (LDHs) isoenzymes of lactate dehydrogenase in human sera can be accomplished by combining variable substrate (lactate or pyruvate) concentrations with specific inhibitors such as urea. 2. One technic useful in the clinical laboratory is based upon a colorimetric assay for total LDH activity in which the oxidation of lactate is couple...

Testis-Specific Lactate Dehydrogenase (LDH-C4) in Skeletal Muscle Enhances a Pika's Sprint-Running Capacity in Hypoxic Environment.

LDH-C4 is a lactate dehydrogenase that catalyzes the conversion of pyruvate to lactate. In mammals, ldh-c was originally thought to be expressed only in testis and spermatozoa. Plateau pika (Ochotona curzoniae), which belongs to the genus Ochotona of the Ochotonidea family, is a hypoxia tolerant mammal living 3000-5000 m above sea level on the Qinghai-Tibet Plateau, an environment which is stro...

Lactate dehydrogenase (LDH) gene duplication during chordate evolution: the cDNA sequence of the LDH of the tunicate Styela plicata.

L-Lactate dehydrogenase (L-LDH, E.C. 1.1.1.27) is encoded by two or three loci in all vertebrates examined, with the exception of lampreys, which have a single LDH locus. Biochemical characterizations of LDH proteins have suggested that a gene duplication early in vertebrate evolution gave rise to Ldh-A and Ldh-B and that an additional locus, Ldh-C arose in a number of lineages more recently. A...

Isozymes of lactate dehydrogenase (LDH) in skeletal tissues of the embryonic and newly hatched chick.

A further study of human seminal plasma lactate dehydrogenase-C4 (LDH-C4): kinetic properties of LDH-C4.

Lactate dehydrogenase-C4 (LDH-C4) from human seminal plasma was purified by 40-60% (NH4)2SO4 precipitation, Oxamate-Sepharose 4B affinity column chromatography and AMP affinity column chromatography. Enzyme kinetic studies of human seminal plasma LDH-C4 were performed with purified LDH -C4. The human LDH-C4 exhibits a much higher affinity for pyruvate and alpha-ketovalerate than lactate. Appare...