Effects of age and magnesium ions on oxygen toxicity in the neonate chicken.
White Leghorn male chicks, 2-6 days and 4 weeks old, were injected with MgCl2 (2 mM Mg/kg body weight) and exposed to 100% O2 at 75 lb/in2 (approximately 5 atm). Compared to saline-injected controls, average time to onset of convulsions was delayed 37% in the younger group with no significant difference in the protective effect during days 2-6. The delay in onset of convulsions was 66% in the 4-week-old group. The protective action of Mg++ in the chick agrees closely with that reported for the mature rat. Chicks treated with Mg++ did not appear depressed. Susceptibility to hyperbaric O2 convulsions increased uniformly between the 2nd and 6th day, with time to onset of convulsions decreasing by 1.4 min/day from the 19.3 +/- 1.01 (SE) min observed at day 2 for saline controls. Between the 6th and 28th day, susceptibility was relatively stable with time to onset decreasing by about 0.2 min/day in controls.
Torley
L W
LW
Department of Physiology, College of Medicine, The Ohio State University, Columbus 43210, USA.
Weiss
H S
HS
D000818:Animals; D000831:Animals, Newborn; D002645:Chickens; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D008274:Magnesium / Q000627:therapeutic use*; D015636:Magnesium Chloride / Q000627:therapeutic use; D008297:Male; D010100:Oxygen / Q000506:poisoning*; D012640:Seizures / Q000209:etiology / Q000517:prevention & control*; D012965:Sodium Chloride / Q000627:therapeutic use
D015636:Magnesium Chloride; D012965:Sodium Chloride; D008274:Magnesium; D010100:Oxygen