Increased number of brain benzodiazepine receptors after in-vivo administration of estazolam to rats.

Estazolam significantly increased the Kd of [3H]flunitrazepam in-vitro, like other benzodiazepines (BDZs) acting competitively at the receptor site. At variance with other BDZs, estazolam significantly raised the Bmax for [3H]flunitrazepam, at concentrations lower than its Ki for BDZ receptors. This effect may be responsible for the observed increase in [3H]diazepam binding after in-vivo administration of estazolam to rats.