Comparative evaluation of mechanism of neuromuscular (n-m) blockade due to enhydrotoxin-A (EsNTx-a) and D-tubocurarine (d-TC).
Effects of major E. schistosa neurotoxin (NTx) EsNTx-a are compared with plant alkaloid d-TC for its onset (LP) and duration of action as the time required for 50% n-m blockade (DT1/2) in normal Ca2+ and modified Ca2+ Krebs Heinsleit (K-H) at two different (low and high) concentrations (conc.). Toxin-EsNTx-a in low Ca2+ K-H and d-TC in both normal and modified Ca2+ K-H did not show LP, whereas LP is increased significantly in 2 Ca2+ K-H in high conc. of EsNTx-a. DT1/2 is increased significantly in high conc. of EsNTx-a and in low conc. of d-TC in 2 Ca2+ K-H. N-m blocking actions are further compared with alpha-bungarotoxin (alpha-BuTx), beta-bungarotoxin (beta-BuTx), and botulinum toxin (B-Tx) for their effects on tetanus, Wednesky inhibition (W.I.), and post tetanic potentiation (PTP).
Department of Pharmacology, Al-Ameen College of Pharmacy, Bangalore, India.
S P
SP
Gawade
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004546:Elapid Venoms / Q000494:pharmacology / Q000633:toxicity*; D017815:Elapidae; D019148:Neuromuscular Blockade; D010791:Phrenic Nerve / Q000187:drug effects; D010946:Plants, Medicinal; D051381:Rats; D014403:Tubocurarine / Q000494:pharmacology / Q000633:toxicity*
D000470:Alkaloids; D015220:Calcium Channels; D004546:Elapid Venoms; D014403:Tubocurarine