The movement of pyruvate, lactate and lactate dehydrogenase into rabbit oviductal fluid

Self Cite

346

199

An ultramicrofluorometric technique was used to analyse the nutrient composition of mouse oviduct fluid. The concentrations of pyruvate, glucose and lactate in the vicinity of the cumulus mass were 0.37, 3.40 and 4.79 mM respectively. In the absence of cumulus cells, the concentration of pyruvate was significantly reduced, to 0.14 mM, while the concentration of glucose was significantly increased to 5.19 mM. Glutamine, which may help to overcome the '2-cell block' in mouse embryos in culture, was present at a concentration of 0.20 mM. A modified medium (MTF) in which the concentration of nutrients was similar to that in mouse oviduct fluid was prepared and its effects on embryo development and metabolism in vitro were compared with that of a conventional embryo culture medium (M16). The percentage of zygotes forming blastocysts in vitro by Day 5 was similar in both media (82% in M16, 79% in MTF). Rates of development, as assessed by cell number, were also comparable. However, the proportion of glucose consumed which was converted to lactate increased dramatically following culture; from 44% in fresh blastocysts, to 73% and 91% in blastocysts derived from 8-cell embryos cultured for 24 h in media MTF and M16 respectively.

Section: Discussionmentioning

confidence: 99%

Concentrations of nutrients in mouse oviduct fluid and their effects on embryo development and metabolism in vitro

Gardner¹,

Leese²

1990

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346

199

“…Although no evidence is available for the rat, pyruvate and lactate are present in fluids secreted by the uterus and the oviduct in rabbits, ewes and sows (Iritani, Gomes & VanDemark, 1969;Iritani, Nishikawa, Gomes & VanDemark, 1971;Iritani, Sato & Nishikawa, 1974;Leese & Aldridge, 1979). Moreover, adequate oxygen is available in the uterus (Nevo, 1965;Yedwab, Paz, Homonnai, Menahem & Kraicer, 1976), and, based on the criteria of motility and energy charge, pyruvate plus lactate is a more effective substrate for rat spermatozoa than glucose.…”

Section: Discussionmentioning

confidence: 99%

The effect of 6-chloro-6-deoxysugars on adenine nucleotide concentrations in and motility of rat spermatozoa

Ford¹,

Harrison²

1981

Spermatozoa from rats treated with 6-chloro-6-deoxyglucose (120 mumol/kg/day) were as motile as those from controls soon after dilution but rapidly became immotile when 3 mM-D-glucose was the only substrate present. Control spermatozoa were more motile when 2 mM-pyruvate + 4 mM-DL-lactate rather than 2 mM-D-glucose was present and the former substrate allowed spermatozoa from treated rats to remain motile. The concentrations of the adenine nucleotides declined rapidly during 40 min incubations when th substrate was 2 mM-D-glucose. The ATP/ADP ratio and the energy charge (ATP + 1/2 ADP/ATP + ADP + AMP) were maintained in spermatozoa from control rats but not in those from treated rats. When the substrate was 2 mM-pyruvate + 4 mM-DL-lactate adenine nucleotides were not lost as rapidly and there was less difference between spermatozoa from control and treated rats.

“…The perfusion experiments were carried out as described by Leese & Aldridge (1979). The oviducts of anaesthetized rabbits were cannulated at their uterine and fimbriated ends and 2 ml 0-9% (w/v) NaCl containing penicillin and streptomycin were recirculated through the lumen at a rate of 50 µ /min for 4 h. Serial samples (50 µ ) of medium were deproteinized with 6% (w/v) HC104, neutralized with 30% (w/v) K2C03 and their pyruvate (and sometimes lactate) content measured by a modification (Leese & Aldridge, 1979) of the automated fluorometric method of Leese & Bronk (1972). In some experiments, the femoral vein was cannulated to allow substances to be infused.…”

Section: Methodsmentioning

confidence: 99%

“…Pyruvic acid is a component of oviductal fluid in a number of species (Brackett & Mastroianni, 1974) and is probably essential to the survival of unfertilized ova and preimplantation embryos up to the 8-cell stage (Biggers & Stern, 1973). The movement of pyruvate into saline medium recirculated for 4 h through the lumen of the rabbit oviduct in vivo has been studied by Leese & Aldridge (1979). The same technique has now been used to examine the effect of compounds which might interact with this pyruvate transport process.…”

Section: Introductionmentioning

confidence: 99%

The stimulation of pyruvate appearance in the rabbit oviduct lumen by sodium propionate

Leese¹

1980

Self Cite

Sodium propionate stimulated the appearance of pyruvte in saline medium recirculated through the lumen of the rabbit oviduct for 4 h in vivo. The propionate was equally effective whether added to the lumen or infused into the bloodstream. The final pyruvate concentration in the lumen in the presence of propionate was 1.3 times that in the plasma. Propionate increased the pyruvate content of oviduct tissue slices incubated in vitro, indicating that a proportion of the propionate-stimulated pyruvate appearance could be due to the metabolic conversion of propionate into pyruvate.