Impact of postnatal dexamethasone on psychotomimetic effects of MK-801 measured on adult rats.
The present study investigates the impact of dexamethasone (DEX) given in tapering doses in the postnatal period on MK-801-induced locomotor activity and MK-801-evoked deficits of sensorimotor gating of adult rats (60 days old). It has been found that DEX given on postnatal day 1 (0.5 microg/g), day 2 (0.3 microg/g) and day 3 (0.1 microg/g) has no effects on spontaneous locomotor activity and does not influence locomotion observed after MK-801 given in a dose of 0.2 and 0.4 mg/kg. Postnatal DEX treatment did not alter the efficacy of sensorimotor gating and its deficits evoked by MK-801 at a dose of 0.2 and 0.4 mg/kg. However, a slight increase in the amplitude of startle reaction has been noted in DEX-treated animals. In conclusion, the results of the present study indicate that DEX given postnatally in tapering doses, although pharmacologically effective (decrease in a gain of body and brain weight), has no potential pro-psychotic effects and does not influence pharmacologically induced psychoses by MK-801. The above data indicate that apart from other side effects, the therapeutic application of DEX in the postnatal period is possibly safe in terms of the risk for developing schizophrenia.
Wedzony
Krzysztof
K
Laboratory of Pharmacology and Brain Biostructure, Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, PL 31-343 Kraków, Poland. nfwedzon@cyf-kr.edu.pl
Markowicz-Kula
Katarzyna
K
Chocyk
Agnieszka
A
Fijał
Katarzyna
K
Przyborowska
Aleksandra
A
Maćkowiak
Marzena
M
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003907:Dexamethasone / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D016291:Dizocilpine Maleate / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D055139:Sensory Gating / Q000187:drug effects
D018691:Excitatory Amino Acid Antagonists; D005938:Glucocorticoids; D016291:Dizocilpine Maleate; D003907:Dexamethasone