Differential effect of changes in blood glucose levels on the velocity of propagation of cortical spreading depression in normal and malnourished rats.
The effects of intravenous glucose (1 ml, 40% solution) and insulin (1.5-3.0 U/kg in 0.2-0.4 ml Ringer solution) on the velocity of propagation (VP) of cortical spreading depression (SD) were studied in 36 well-nourished (W) and 25 malnourished (M) adult (90 days old) Wistar rats of both sexes. Blood glucose levels, measured 40-70 min after glucose, were increased by 330% in the W group (N = 18) and by 202.9% in the M rats (N = 12), when compared to the pre-injection levels. Insulin decreased it by 43.5% and 61.2% in W and M rats, respectively (N = 13). In the W rats, SD VP decreased after glucose and increased after insulin. The effect of glucose could not be attributed to increases in blood osmolarity, since iv mannitol (1 ml, 20% solution, N = 5) failed to decrease SD VP. The mean +/- SEM VP before and after the treatments were as follows (in mm/min): W rats, glucose 3.31 +/- 0.16 and 3.11 +/- 0.13; insulin 3.50 +/- 0.12 and 3.81 +/- 0.11; mannitol 3.53 +/- 0.46 and 3.92 +/- 0.48. In the M rats, the above effects on SD were not seen (SD VP: glucose 3.89 +/- 0.20 and 4.13 +/- 0.24; insulin 3.51 +/- 0.19 and 3.63 +/- 0.17). The results suggest that changes in the production of brain energy influence SD propagation.
Ximenes-da-Silva
A
A
Departamento de Nutrição, Universidade Federal de Pernambuco, Recife, PE, Brasil.
Guedes
R C
RC
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000187:drug effects; D013181:Cortical Spreading Depression / Q000187:drug effects / Q000502:physiology*; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D007275:Injections, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology; D008353:Mannitol / Q000494:pharmacology; D011502:Protein-Energy Malnutrition; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D007328:Insulin; D008353:Mannitol; D005947:Glucose