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.
Sharma
H S
HS
Department of Physiology, Banaras Hindu University, Varanasi, India.
Dey
P K
PK
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