Phosphate is required for inhibition by glucose of development of hamster 8-cell embryos in vitro.
The influence of sodium dihydrogen phosphate (Pi) and glucose on the development of hamster 8-cell embryos mediated by pyruvate (P) or amino acids (A) or lactate (L) was investigated using modified Tyrode's medium, TLP-PVA. When pyruvate was tested as the only energy substrate in medium TP-PVA for embryo development, blastocyst formation ranged from 81.3 to 90.9% whether or not the medium contained 0.35 mM Pi or 5 mM glucose; but, when these two compounds were present together, blastocyst formation fell to 51.8%. Similarly, in TA-PVA medium containing four amino acids: Phe, Ile, Met, and Gln), embryo development to blastocyst ranged from 74.1% to 90.4% whether or not the medium contained 0.35 mM Pi or 5 mM glucose; but, when these compounds were present together, blastocyst formation fell to 16.0%. In TL-PVA medium, 10 mM sodium lactate supported embryo development (84.4% blastocysts); the addition of 0.35 mM Pi decreased blastocyst development to 65.6%. However, addition of glucose to Pi-free TL-PVA medium did not decrease blastocyst formation (81.3%); when the medium contained 0.35 mM Pi, glucose curtailed blastocyst development to 7.5%. When glucose and Pi interactions were studied at different concentrations, glucose up to 1 mM was not inhibitory in Pi-free TL-PVA medium (74.3% blastocysts), but 0.25 mM glucose in the presence of 0.35 mM Pi markedly inhibited embryo development (7.7% blastocysts). Phosphate at a relatively high concentration (1 mM) was inhibitory (37.9% blastocysts), even in the absence of glucose.(ABSTRACT TRUNCATED AT 250 WORDS)
Seshagiri
P B
PB
Department of Veterinary Science, University of Wisconsin-Madison 53706.
Bavister
B D
BD
D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001755:Blastocyst / Q000187:drug effects; D006224:Cricetinae / Q000196:embryology*; D003847:Deoxyglucose / Q000494:pharmacology; D047108:Embryonic Development; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D066298:In Vitro Techniques; D007773:Lactates / Q000494:pharmacology; D008647:Mesocricetus / Q000196:embryology*; D010710:Phosphates / Q000494:pharmacology*; D011247:Pregnancy; D011773:Pyruvates / Q000494:pharmacology
D000596:Amino Acids; D007773:Lactates; D010710:Phosphates; D011773:Pyruvates; D003847:Deoxyglucose; D005947:Glucose