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Biomedical subjects

L F Beebe

Publications and source records attributed to L F Beebe.

4 recordsLinked to original sources
PubMed1991

Maternal diabetes and retarded preimplantation development of mice.

The streptozocin-induced diabetic (STZ-D) mouse was found to be a suitable model for studying the effects of maternal diabetes on the preimplantation embryo. This study looked at the effects of maternal diabetes on embryonic growth. Female Quakenbush mice were made diabetic (plasma glucose levels greater than 20 mM) by injection of 190 mg/kg i.p. STZ and were superovulated by standard methods. The blastocysts collected on day 4 from diabetic mothers had 8.5% fewer cells and a 35% lower protein synthetic rate than control embryos. Their cellular protein synthetic rate was 19% less than that in controls. Morulae from diabetic mothers also displayed a reduced protein synthetic rate, but this reduction was not seen in the two-cell embryo. Furthermore, blastocysts cultured in vitro from two-cell embryos from diabetic and control mothers displayed similar protein synthetic rates. This infers that the two-cell embryos from diabetic mothers are normal, and the retardation seen in later development in vivo occurs after the two-cell stage while the embryo is still free in the oviductal and uterine environment. Treatment of the diabetic mice with ultralente insulin every 12 h raised the protein synthetic rate of those blastocysts toward control levels, whereas treatment with lente insulin every 8 h recovered the embryo to the same rate as the control embryos. Because insulin has been shown to be mitogenic and stimulates protein synthesis of morulae and blastocysts in vitro, the absence of insulin in the diabetic mothers may be the cause of the retardation observed in their preimplantation embryos.

Animals↗
PubMed1990

Preimplantation development in the streptozotocin-induced diabetic mouse.

Streptozotocin (STZ) was used to develop a diabetic mouse model in which to study the development of the preimplantation embryo. STZ doses of 0, 160, 190, 210 and 240 mg kg-1 were given; 190 mg kg-1 was found to be the most suitable as the standard diabetogenic dose, providing about 60% mice with plasma glucose greater than 20 mM. The STZ-diabetic mice responded to superovulation with 10 i.u. of gonadotrophin in the same manner as control mice, producing similar embryo numbers at 48 h, 72 h and 96 h post-hCG. Furthermore, the proportion of 2-cell embryos collected from STZ-diabetic mice which developed to blastocysts in vitro was similar to that of 2-cell embryos from control mice. The STZ-diabetic mouse model after superovulation thus produced normal early preimplantation embryos whose development can be examined in detail in a diabetic environment.

Animals↗