Cl. Kowalczyk et al., EFFECTS OF ALCOHOLS ON MURINE PREIMPLANTATION DEVELOPMENT - RELATIONSHIP TO RELATIVE MEMBRANE DISORDERING POTENCY, Alcoholism, clinical and experimental research, 20(3), 1996, pp. 566-571
During in vitro culture of murine preimplantation embryos, we have obs
erved that exposure to 0.1% ethanol induces an immediate increase in i
ntracellular calcium levels and subsequently accelerates embryogenesis
. If the observed effects of ethanol on developing embryos is mediated
by its membrane disordering potency, we hypothesized that the relativ
e membrane disordering potencies of related alcohols would correspondi
ngly effect embryonic intracellular calcium levels and developmental r
ates. Two-cell embryos were exposed to 0.1% ethanol or 0.05 to 1.0% (w
/v) n-butanol, n-propanol, isopropanol, 1,2-propanediol, glycerol, or
methanol for 24 hr at 37 degrees C, and development to the blastocyst
stage was monitored after 5 days. n-Butanol, n-propanol, isopropanol,
and methanol treatment caused a dose-dependent inhibition (p < 0.01) o
f development to the blastocyst stage, whereas 1,2-propanediol or glyc
erol neither accelerated nor inhibited development. In a second experi
ment, 8-cell morulae were treated with 1,2-propanediol or glycerol, an
d cavitation rates were examined. There was no significant difference
from control embryos in the onset of cavitation or the blastocoel expa
nsion rate of 1,2-propanediol- or glycerol-exposed embryos, whereas ex
posure to 0.1% ethanol accelerated cavitation (p > 0.05). In a third e
xperiment, morulae were exposed to 0.1% or 1.0% of each alcohol and we
re monitored for changes in intracellular calcium levels using the flu
orescent indicator, fluo-3-acetoxymethyl ester. There was an immediate
increase in intracellular calcium levels when morulae were treated wi
th 1.0% ethanol or n-butanol, but only ethanol induced an increase (p
< 0.05) in the level of intracellular calcium at 0.1%. These data sugg
est that ethanol is unique in its ability to accelerate embryogenesis
and that the membrane disordering potency of ethanol does not directly
underlie its effects on intracellular calcium release and the acceler
ation of preimplantation development.