Multiple Dose Pyridostigmine Administration: Cardiovascular Effects at Rest during Acute Heat and Altitude Exposure
Abstract
Two separate studies of pyridostigmine bromide ingestion (PB, 30 mg, t.i.d.) were conducted. In one study, five subjects were studied at rest in a hot environment (35'C) . In a second study, four subjects were studied in a warm environment (31'C) at sea level and at 10,000 feet. Esophageal (Tes) temperature, heart rate (HR), arterial blood pressure, forearm blood flow and forearm skin blood flow were measured. Red blood cell cholinesterase activity (RBC AchE) was used as an index of PB effectiveness. RBC AchE activity was inhibited -31 to -47%. In STUDY 1, resting T.. and heart rate were lower after 50 hours of pyridostigmine ingestion compared to control (36.60+/- 0.08'C vs 36. 82+/- 0.08'C; 58+/-11 b-min-1 vs 69+/- 13 b-min-1, P<0.05). In STUDY 2, Tes was lower at altitude (36.60+/- 0.06'C vs 36.84+/-O.14'C, p<0.05) and tended to be lower after 74 hours of pyridostigmine treatment (36.75+/- 0.15) at sea level compared to control. HR was lower at sea level 74 hours after PB (60 +/- 8 b- min-1 vs 68 +/- 14, p<0.05). It appears that multiple low dose PB subtly lowers HR and Tes in a hot environment and lowers HR in a warm environment. The effect on HR can probably be explained by cholinergic (vagal) stimulation, whereas the effect on Tes is unexplained.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1991
- Accession Number
- ADA248476
Entities
People
- Lou A. Stephenson
- Margaret A. Kolka
- Penny W. Burgoon
Organizations
- United States Army Research Institute of Environmental Medicine