Malaoxon-induced brain phosphoinositide turnover and changes in brain calcium levels by female gender in pregnant and non-pregnant convulsing and non-convulsing rats.
Alterations in malaoxon-(MO)-induced brain regional phosphoinositide (PI) turnover and in brain calcium levels were studied in female non-pregnant and pregnant rats, and in their offspring. The adult rats were followed for 1 or 4 h after MO for tonic-clonic convulsions. A dose of 8.2 mg kg-1 of MO caused similar convulsions in 74% of the pregnant rats as we have reported in young male rats with a dose of 39.2 mg kg-1. However, convulsions did not occur in non-pregnant female rats. Inositol and inositol monophosphate levels were similar in all control rats. MO decreased brain inositol both in pregnant and non-pregnant female rats, and in the cerebellum of the offspring. In contrast to the findings in male rats, MO only randomly increased brain inositol-1-phosphate in female rats, or in their offspring. However, cerebral inositol-4-phosphate levels were similarly increased both in the non-pregnant and the pregnant rats irrespectively of convulsions. MO did not elevate cerebral Ca2+ in female rats or their offspring, in contrast to the male rats. The present results suggest that female rats are more sensitive than male rats to MO-induced PI signalling, and during pregnancy, also to MO-induced overt convulsions, but not to changes in cerebral Ca2+.
Hirvonen
M R
MR
Division of Environmental Health, National Public Health Institute, Kuopio, Finland.
Savolainen
K M
KM
D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D002849:Chromatography, Gas; D005260:Female; D008294:Malathion / Q000031:analogs & derivatives* / Q000633:toxicity; D008297:Male; D010716:Phosphatidylinositols / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D012640:Seizures / Q000139:chemically induced* / Q000378:metabolism; D012737:Sex Factors; D015398:Signal Transduction / Q000502:physiology
D010716:Phosphatidylinositols; C100082:malaoxon; D002118:Calcium; D008294:Malathion