Probable involvement of 5-hydroxytryptamine in increased permeability of blood-brain barrier under heat stress in young rats.
Exposure of young rats (9-10 weeks) to chronic summer heat (36 degrees C) or acute heat (38 degrees C, 4 hr) increased the permeability of the blood-brain barrier (BBB) to Evans blue albumin complex and [131I]sodium in different regions of the brain, which correlated well with the increased level of 5-hydroxytryptamine (5-HT) in plasma and brain. This increased permeability of the blood-brain barrier and the increased level of 5-HT were prevented by pretreatment with para-chlorophenylalanine (p-CPA), indomethacin and diazepam. Pretreatment with cyproheptadine and vinblastine, however, prevented only the increased permeability of the blood-brain barrier; the plasma and level of 5-HT in brain continued to remain high. These results indicate a probable role of 5-HT as one of the factors leading to the increased permeability of the blood-brain barrier in young rats following heat stress.
D000375:Aging; D000818:Animals; D001794:Blood Pressure; D001812:Blood-Brain Barrier; D001831:Body Temperature; D003533:Cyproheptadine / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D005260:Female; D010134:Fenclonine / Q000494:pharmacology; D006358:Hot Temperature; D007213:Indomethacin / Q000494:pharmacology; D007457:Iodine Radioisotopes; D008297:Male; D051381:Rats; D012701:Serotonin / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*; D014747:Vinblastine / Q000494:pharmacology
D007457:Iodine Radioisotopes; D003533:Cyproheptadine; D012701:Serotonin; D014747:Vinblastine; D003975:Diazepam; D010134:Fenclonine; D007213:Indomethacin