title: Prophylactic corticosteroid increases survival in experimental heat stroke in primates.
abstract: It has been suggested that endotoxins or lipopolysaccharides (LPS), may contribute to heat stroke pathophysiology. In this study, 11 anesthetised monkeys were divided into 2 groups. The steroid group (n = 5) had received a dose of MPSS (30 mg.kg-1, i.v.) before being heat-stressed and the control animals (n = 6) received saline equivolumetrically. The animals were heat-stressed to a rectal temperature of 43.5 degrees C in an environmental temperature of 41 +/- 0.3 degrees C and 100% relative humidity and then allowed to recover at room temperature. Blood samples for LPS and anti-LPS IgG analyses were taken both before treatment and before and after heat-stress. The administration of prophylactic MPSS increased the survival rate significantly from 33% to 100% (p less than 0.05). The plasma LPS level in the steroid group showed very little change after heat-stress, whereas in the non-surviving controls there was a significant increase in plasma LPS level (from 0.089 +/- 0.007 to 0.257 +/- 0.031 ng.ml-1) (p less than 0.005). The control animals that survived showed very little increase in plasma LPS levels, but had about 300% greater plasma Anti-LPS IgG levels. We conclude that pretreatment with MPSS improves the survival rate during heat stroke, possibly by suppressing the rise in plasma LPS concentration.
authors.affiliation: Department of Physiology, University of Natal Medical School, Durban, South Africa.
authors.forename: P
authors.initials: P
authors.lastname: Gathiram
authors.forename: M T
authors.initials: MT
authors.lastname: Wells
authors.forename: J G
authors.initials: JG
authors.lastname: Brock-Utne
authors.forename: S L
authors.initials: SL
authors.lastname: Gaffin
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D005260:Female; D006359:Heat Exhaustion / Q000517:prevention & control*; D007074:Immunoglobulin G / Q000378:metabolism; D008070:Lipopolysaccharides / Q000097:blood; D008297:Male; D008775:Methylprednisolone / Q000031:analogs & derivatives*; D008776:Methylprednisolone Hemisuccinate / Q000097:blood / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D007074:Immunoglobulin G; D008070:Lipopolysaccharides; D008776:Methylprednisolone Hemisuccinate; D008775:Methylprednisolone