AbstractsMedical & Health Science

It is possible to evaluate the effects of glucose and insulin on feline embryonic development using in vitro fertilization and embryo culture. The objective of this study was to determine if glucose concentrations greater than ??? 6 mM with or without varying concentrations of insulin would affect cleavage or blastocyst development of feline embryos. We hypothesized that high concentrations of glucose or insulin in culture media would result in a decrease in the proportion of embryos that cleaved and formed blastocysts. Our findings show that 24 mM D-glucose was inhibitory (P>0.05) to the early feline embryo in two of three experiments. These effects of glucose were not due to osmotic changes in the media because the same concentration of L-glucose (not taken up by the embryo) did not produce the same effects. The negative effects of glucose were also more pronounced when excess glucose was present as 2-deoxyglucose, which can be metabolized to 2-deoxy glucose 6 phosphate, but not further. From the literature, it was expected the lower doses of insulin to be stimulatory and the higher doses to be inhibitory. In this study, exactly the opposite was found to be observed in feline embryos. There is not much information about insulin signaling in the feline blastocyst, and it is possible that our data was in part due to a response specific to the domestic cat. The concentrations of glucose and insulin in oviductal and uterine fluid are related to plasma concentrations so that metabolic conditions such as insulin resistance, hyperglycemia, and type 2 diabetes that affect circulating concentrations of glucose and insulin may also affect the development of feline embryos in vivo.