Nitrous oxide alters body laterality in rats.

Area of Science:

• Developmental toxicology
• Teratology
• Reproductive toxicology

Background:

• Nitrous oxide (N2O) is a common anesthetic agent used in surgical procedures.
• Potential reproductive and developmental risks associated with N2O exposure are not fully understood.

Purpose of the Study:

• To investigate the effects of N2O exposure on embryonic/fetal development and laterality in a rat model.
• To assess the impact of N2O on embryo/fetal mortality and morphological asymmetry.

Main Methods:

• Timed-pregnant Sprague-Dawley rats were exposed to 75% N2O or air (control) for 24 hours on day 8 of gestation.
• Embryo/fetal viability and specific morphological parameters related to body asymmetry were assessed from day 11 to day 20.
• Mortality rates and incidence of altered laterality were compared between N2O-exposed and control groups.

Main Results:

• N2O exposure significantly increased embryo/fetal mortality starting on day 14 of gestation (40.8% vs. 8.9% in controls).
• A substantial increase in altered laterality was observed in the N2O group (31.3%) across all developmental stages assessed.
• Control group exhibited minimal altered laterality, with only 9% showing left-sided orientation on day 16.

Conclusions:

• Acute N2O exposure during a critical period of gestation induces significant developmental toxicity, including increased mortality and pervasive laterality defects.
• The findings suggest potential risks of N2O exposure for pregnant surgical patients and occupationally exposed workers.
• Further research is needed to elucidate the underlying mechanisms and long-term implications of N2O-induced developmental toxicity.