TERATOLOGY 46:85-89 (1992)
In Vitro Exposure of Preimplantation Mouse Embryos to Cocaine and Benzoylecgonine Inhibits Subsequent Development ROBERT A. KAUFMANN AND D. RANDALL ARMANT C. S. Mott Center for Human Growth and Deuelopment, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan 48201
ABSTRACT Cocaine is used by over 20% of women of reproductive age. Although there have been numerous studies focusing on its effects on reproductive processes, none has evaluated its direct effect on preimplantation development. We have investigated the effect of cocaine and its major metabolite, benzoylecgonine, on in vitro preimplantation mouse embryogenesis. One-cell embryos were exposed a t the one-, two-, four-, or eight-cell stage for 24 hr to medium containing 0-400 pg/ml cocaine or benzoylecgonine and then cultured to the blastocyst stage. Cocaine had its strongest inhibitory effect at the earliest stages of development. At the one- and two-cell stages, there was a significant inhibition of blastocyst formation following exposure to cocaine concentrations of 25-400 pg/ml, and at the four-cell stage there was an inhibitory effect at 100 and 400 pglml cocaine. Benzoylecgonine inhibited the development of embryos to blastocyst only a t the one- and two-cell stages, at concentrations of 100-400 pg/ml. These findings suggest that cocaine is capable of blocking preimplantation embryogenesis, particularly following exposure at the earliest stages, and that this toxicity may abate as cocaine is biotransformed to benzoylecgonine. Q 1992 Wiley-Liss, Inc.
Approximately 21% of women aged 26-34 years in the United States, prime childbearing years, have used cocaine (NIDA, '89). Many studies have evaluated the influence of cocaine on reproduction (Ravitz and Moore, '77; Gordon et al., 'SO; Berul and Harclerode, '89; Mendelson et al., '89); however, very few have investigated its periconceptual or early embryological effects. We previously found that the short-term, in vivo administration of cocaine to rabbits prior to ovulation did not influence subsequent early embryogenesis following in vitro fertilization (Kaufmann et al., '90). In contrast, others have found that in vivo cocaine-treated rabbit embryos demonstrated compromised development in vitro compared with controls (Atlas and Wallach, '91). In another species, the rat, cocaine inhibited the growth of postimplantation embryos in culture in a concentration-dependent manner (El-Bizri et al., '91). The effect of cocaine exposure on embryos between 0 1992 WILEY-LISS, INC.
these two periods of development has not been investigated. Although it appears that the majority of infants born t o cocaine-using mothers are developmentally normal, numerous birth defects have been attributed to cocaine teratogenicity, including skeletal (Bingo1 et al., '€471, cardiac (Little et al., '891, urogenital (Chasnoff et al., '89), and intestinal (Hoyme et al., '90) deformities. To ascertain whether critical periods of preimplantation embryogenesis exist that are influenced by cocaine exposure, we utilized an in vitro culture system to evaluate the direct effect of this drug on the preimplantation embryo and its subsequent development to the blastocyst stage, independent of any mediating Received November 12,1991; accepted February 26,1992. Rabert A. Kaufmann's present address is The Jones Institute for Reproductive Medicine, Eastern Virginia Medical College, 601 Colley Ave, Norfolk, VA 23507. Address reprint requests t o D. Randall Armant, C . S. Mott Center, 275 East Hancock, Detroit, MI 48201.
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R.A. KAUFMANN AND D.R. ARMANT
TABLE 1 . Effect Stage of embryo exposure One-cell Two-cell Four-cell Eight-cell
0 64 (145)' 78 (118) 82 (112) 88 (103)
of
in uitro cocaine exposure on embryo deuelopment Cocaine (pglml) 25 50 100 35 (48)* 30 (50)* 11 (46)* 47 (34)* 40 (38)* 31 (35)* 84 (31) 84 (31) 56 (36)* 87 (31) 93 (27) 93 (33)
400 5 (44)* 3 (40)* 46 (37)* 78 (37)
'Percentage of embryos prweding to the blastocyst stage (total number of embryos initially exposed) *P
In Vitro Exposure of Preimplantation Mouse Embryos to Cocaine and Benzoylecgonine Inhibits Subsequent Development ROBERT A. KAUFMANN AND D. RANDALL ARMANT C. S. Mott Center for Human Growth and Deuelopment, Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan 48201
ABSTRACT Cocaine is used by over 20% of women of reproductive age. Although there have been numerous studies focusing on its effects on reproductive processes, none has evaluated its direct effect on preimplantation development. We have investigated the effect of cocaine and its major metabolite, benzoylecgonine, on in vitro preimplantation mouse embryogenesis. One-cell embryos were exposed a t the one-, two-, four-, or eight-cell stage for 24 hr to medium containing 0-400 pg/ml cocaine or benzoylecgonine and then cultured to the blastocyst stage. Cocaine had its strongest inhibitory effect at the earliest stages of development. At the one- and two-cell stages, there was a significant inhibition of blastocyst formation following exposure to cocaine concentrations of 25-400 pg/ml, and at the four-cell stage there was an inhibitory effect at 100 and 400 pglml cocaine. Benzoylecgonine inhibited the development of embryos to blastocyst only a t the one- and two-cell stages, at concentrations of 100-400 pg/ml. These findings suggest that cocaine is capable of blocking preimplantation embryogenesis, particularly following exposure at the earliest stages, and that this toxicity may abate as cocaine is biotransformed to benzoylecgonine. Q 1992 Wiley-Liss, Inc.
Approximately 21% of women aged 26-34 years in the United States, prime childbearing years, have used cocaine (NIDA, '89). Many studies have evaluated the influence of cocaine on reproduction (Ravitz and Moore, '77; Gordon et al., 'SO; Berul and Harclerode, '89; Mendelson et al., '89); however, very few have investigated its periconceptual or early embryological effects. We previously found that the short-term, in vivo administration of cocaine to rabbits prior to ovulation did not influence subsequent early embryogenesis following in vitro fertilization (Kaufmann et al., '90). In contrast, others have found that in vivo cocaine-treated rabbit embryos demonstrated compromised development in vitro compared with controls (Atlas and Wallach, '91). In another species, the rat, cocaine inhibited the growth of postimplantation embryos in culture in a concentration-dependent manner (El-Bizri et al., '91). The effect of cocaine exposure on embryos between 0 1992 WILEY-LISS, INC.
these two periods of development has not been investigated. Although it appears that the majority of infants born t o cocaine-using mothers are developmentally normal, numerous birth defects have been attributed to cocaine teratogenicity, including skeletal (Bingo1 et al., '€471, cardiac (Little et al., '891, urogenital (Chasnoff et al., '89), and intestinal (Hoyme et al., '90) deformities. To ascertain whether critical periods of preimplantation embryogenesis exist that are influenced by cocaine exposure, we utilized an in vitro culture system to evaluate the direct effect of this drug on the preimplantation embryo and its subsequent development to the blastocyst stage, independent of any mediating Received November 12,1991; accepted February 26,1992. Rabert A. Kaufmann's present address is The Jones Institute for Reproductive Medicine, Eastern Virginia Medical College, 601 Colley Ave, Norfolk, VA 23507. Address reprint requests t o D. Randall Armant, C . S. Mott Center, 275 East Hancock, Detroit, MI 48201.
86
R.A. KAUFMANN AND D.R. ARMANT
TABLE 1 . Effect Stage of embryo exposure One-cell Two-cell Four-cell Eight-cell
0 64 (145)' 78 (118) 82 (112) 88 (103)
of
in uitro cocaine exposure on embryo deuelopment Cocaine (pglml) 25 50 100 35 (48)* 30 (50)* 11 (46)* 47 (34)* 40 (38)* 31 (35)* 84 (31) 84 (31) 56 (36)* 87 (31) 93 (27) 93 (33)
400 5 (44)* 3 (40)* 46 (37)* 78 (37)
'Percentage of embryos prweding to the blastocyst stage (total number of embryos initially exposed) *P
