General anaesthetics introduction

What is special about these steroids (alphaxalone and alphadolone) is their novel effect as anaesthetics and their chemical similarity to progesterone (Fig. 2). It was Seyle (1941) who first noted the general anaesthetic effect of progesterone, when injected in large amounts intravenously in rats. The background for the introduction of steroid anaesthetics has been reviewed by Sutton (1972). The review by Phillips (1974) of the structure-activity relationships of steroidal anaesthetics is recommended for further reference. 

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