Effects of Pressure and Muscle Loading on the Toxic Actions of Echinoderm Saponins in Neuromuscular Tissues
Abstract
The toxic marine saponin holothurin A from the Bahamian sea cucumber has been studied with regard to potency in blockade of responses of phrenic nerve-diaphragm (PN-D) preparations from the rat and the guinea pig under the additional stresses of high environmental pressure or variable loading of the muscle. In the rat tissue, the toxin (H(-)) and its desulfated derivative (DeH) afford a contrast in sensitivity to the effects of elevated pressure: (a) the potency of H(-) at 1.0 x .0001M is quite high at 14.7 psia, falls sharply as pressure is increased to 130 psia, and then increases moderately as pressure is further raised toward 330 psia; (b) the effect of increased pressure on DeH potency is only marginal. At ambient pressure, the effectiveness of 1.0 x . 0001MH(-) in depressing twitch responses of rat or guinea pig PN-D preparations is quite high near zero loading of the muscle, and falls to negligible levels as the static loading factor is increased toward 10-20 g/g of tissue. These observations are interpreted in terms of a working model for toxin receptors in junctional areas of PN-D tissues. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 26, 1971
- Accession Number
- AD0744913
Entities
People
- J. D. Chanley
- R. C. Durant
- S. L. Friess
- W. L. Fink
Organizations
- Naval Medical Research Center