Accession Number:

ADA248476

Title:

Multiple Dose Pyridostigmine Administration: Cardiovascular Effects at Rest during Acute Heat and Altitude Exposure

Descriptive Note:

Technical rept.,

Corporate Author:

ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Report Date:

1991-12-01

Pagination or Media Count:

26.0

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 35C . In a second study, four subjects were studied in a warm environment 31C 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- 0.08C vs 36. 82- 0.08C 58-11 b-min-1 vs 69- 13 b-min-1, P0.05. In STUDY 2, Tes was lower at altitude 36.60- 0.06C vs 36.84-O.14C, p0.05 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, p0.05. 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.

Subject Categories:

  • Biology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE