5β-Reduced Neuroactive Steroids Are Novel Voltage-Dependent Blockers of T-Type Ca2+ Channels in Rat Sensory Neurons in Vitro and Potent Peripheral Analgesics in Vivo

Abstract
T-type Ca2+ channels are believed to play an important role in pain perception, and anesthetic steroids such as alphaxalone and allopregnanolone, which have a 5α-configuration at the steroid A, B ring fusion, are known to inhibit T-type Ca2+ channels and cause analgesia in a thermal nociceptive model (