Comparison of cutaneous and in vitro histamine release by muscle relaxants

The authors compared histamine release in vitro in a human neonatal foreskin preparation to histamine release in vivo in adult humans with three commonly used muscle relaxants (vecuronium, atracurium, and d-tubocurarine) in concentrations ranging from 10(-1) M to 3 X 10(-3) M. They measured histamine release directly in the in vitro preparation and measured the wheal size resulting from intradermal injection in vivo. Both in vivo and in vitro testing revealed dose-related histamine release with d-tubocurarine and atracurium (P less than .05). Vecuronium did not release histamine at any concentration. It was concluded that the infant foreskin model is a valid predictor of histamine release by muscle relaxants in vivo, and can provide valuable information about mechanisms of histamine release by these, and perhaps others, drugs used in anesthetic practice.