[Extracellular calcium in the rat brains and the effects of nifedipine in experimental cerebral infarction using calcium ion selective microelectrodes in vivo].
Extracellular Ca2+ (Ca2+ e) changes in the cerebral infarction areas of the rats with the double-tubulus calcium ion-selective microelectrodes made of calcium active material, di-2-isooctylphenyl calcium phosphate to observe the effects of two concentrations of nifedipine given before the middle cerebral artery (MCA) occlusion. Twenty-four rats were divided into three groups: group A: with just the left MCA occlusion, Group B: with intramuscular injection of nifedipine 1mg/kg one hour before the MCA occlusion, and Group C with intramuscular injection of nifedipine 5mg/kg one hour before the MCA occlusion. The results indicated that the mean concentration of Ca2+ e in the normal brain Group A was 1.119 mM. The Ca2+ e concentrations became 0.4613 mM, 0.191 mM and 0.0654 mM, 2, 5 and 30 minutes after the MCA occlusion respectively. The other groups, Group B and Group C, receiving two kinds of dosages of nifedipine respectively showed the Ca2+ e concentrations to be 0.5262 mM and 0.5588 mM, 0.3456 mM and 0.3058 mM, 0.2156 mM and 0.1989 mM, 2, 5 and 30 minutes after the MCA occlusion respectively. There is no statistic significance between group B and group c (P greater than 0.25) By comparing Group A with Group B or C, it was found that the Ca2+ e level of Group B or C is about 3 times greater than that of Group A (P less than 0.0025) and (P less than 0.005) 30 minutes after the MCA occlusion.
Niu
G
G
ReiJin Hospital, Shanghai Second Medical University.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D002544:Cerebral Infarction / Q000378:metabolism*; D005110:Extracellular Space / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008839:Microelectrodes; D009543:Nifedipine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D015220:Calcium Channels; D009543:Nifedipine; D002118:Calcium