Neonatal neuronal apoptosis after betamethasone administration in pregnant Wistar rats

Abstract

Objective: To analyze the apoptosis of cortical and hippocampal neurons in newborn following the intramuscular administration of betamethasone in pregnant Wistar rats.

Methods: Betamethasone or placebo was administered to 10 pregnant rats. Subsequently, 98 newborns were analyzed in three different groups: therapeutic dose (TD, 20 mg/kg), triple therapeutic dose (3TD, 60 mg/kg), and nine times TD (9TD, 180 mg/kg). Forty-four newborns were injected with placebo (control subjects – CTR). Neuronal apoptosis was measured by immunofluorescence using the TUNEL assay. The one-way analysis of variance, Tukey–Kramer (parametric) test and Kruskal–Wallis (non-parametric) test were used for statistical analysis.

Results: The CA1 area of the hippocampus of TD and 3TD groups showed significant differences from that of the CTR group (p < 0.001). Compared to the CTR group, there was increased neuronal apoptosis in the dentate gyrus (DG) of animals in TD and 3TD groups (p < 0.0001). There were no significant differences in CA2 and CA3 regions as well as in amygdala and cortex.

Conclusion: Prenatal administration of betamethasone leads to significant changes in neuronal apoptosis in CA1 and DG regions.

• Betamethasone
• immunofluorescence
• neonatal neuronal apoptosis
• pregnancy
• TUNEL assay
• Wistar rats

Acknowledgements

This work was supported by FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) Grant No. 04/00877-0.

Declaration of interest

The authors declare no conflicts of interests.