Newborn piglets exposed to hypoxia after nicotine or saline pretreatment: Long-term effects on brain and heart

Abstract

Objective. We wished to assess the effect of global hypoxia and the effect of nicotine pretreatment on the brain and heart of newborn pigs. Hypothesising that nicotine might give a better outcome because of its anti-apoptotic and anti-inflammatory effects.

Methods. Twenty-two anaesthetised piglets were randomised to pretreatment with saline or nicotine (130 μg/kg/h) before 45 min global hypoxia. They were observed for 27 h. The brain and heart were assessed with histopathological methods. Serum for Troponin t (TnT) analyses was collected at baseline and at the end of the experiment.

Results. There were no significant differences between the groups. At the end of hypoxia, BE was −14.8 ± 4.9 mmol/l and MABP was 25 ± 9 mmHg. Seven animals had autolysis of the cerebrum/cerebellum, their BE after hypoxia was −19 ± 1.8 mmol/l and MABP 23 ± 3 mmHg. The remaining 15 animals had a BE of −13 ± 4.7mmol/l (p = 0.0004) and a MABP of 26 ± 11 mmHg (ns). Eleven animals presented myocardial damage. A significant increase in TnT occurred in both groups. TnT increase and myocardial damage correlated (p = 0.001; r = 0.67). Animals with severe increase in TnT presented severe brain damage.

Conclusions. Severe increase in serum TnT levels was linked to severe cerebral damage. Nicotine pretreatment had no impact on cerebral or cardiac histopathology.

Keywords:

• Hypoxia
• nicotine
• troponin t
• newborn pigs
• piglets