Influence of long-term acute heat exposure on regional blood-brain barrier permeability, cerebral blood flow and 5-HT level in conscious normotensive young rats.
Exposure of conscious young rats to 4 h heat stress at 38 degrees C in B.O.D. incubator was associated with increased blood-brain barrier (BBB) permeability in 14 brain regions studied. In the same regions cerebral flow (CBF) diminished by 4-65%, but the magnitude of flow reduction was not correlated with the degree of increased BBB permeability. On the other hand, a correlation was observed with increased plasma and brain 5-hydroxytryptamine (5-HT) levels. p-Chlorophenylalanine (p-CPA), indomethacin and diazepam pretreatment prevented both the increased BBB permeability and 5-HT levels following heat exposure. Whereas cyproheptadine and vinblastine pretreatment prevented the increased BBB permeability alone. The probable mechanism(s) underlying the BBB permeability is discussed.
Department of Physiology, Banaras Hindu University, Varanasi, India.
H S
HS
Sharma
P K
PK
Dey
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects; D001921:Brain / Q000502:physiology*; D002560:Cerebrovascular Circulation; D003533:Cyproheptadine / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D005260:Female; D006358:Hot Temperature; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009928:Organ Specificity; D010539:Permeability; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012701:Serotonin / Q000378:metabolism*; D014747:Vinblastine / Q000494:pharmacology
D003533:Cyproheptadine; D012701:Serotonin; D014747:Vinblastine; D003975:Diazepam; D007213:Indomethacin