Lillian Mary Pickford. 14 August 1902—14 August 2002

Abstract

Mary Pickford was an experimental physiologist who carried out pioneering work on the actions of the hormones (oxytocin and vasopressin [ syn. antidiuretic hormone, ADH]) secreted by the posterior pituitary gland, which is part of the brain. She provided understanding of how the secretion of these hormones is controlled to regulate body fluid composition, specifically the maintenance, through actions on the kidneys, of normal osmolarity and Na + concentration, and hence blood volume and pressure. Using the water-loaded dog model she showed that vasopressin is the only hormone that regulates the excretion of water, by stimulating the kidneys to concentrate urine; she found that oxytocin could stimulate excretion of Na + . She showed that acetylcholine is an excitatory neurotransmitter in the hypothalamus, stimulating the neurons that produce vasopressin to secrete—the first evidence for acetylcholine action in the brain. The principles that Mary established have been extensively confirmed; hence, she was important in the establishment of the concepts and discipline of neuroendocrinology, which is about the bidirectional interactions between hormones and the brain. Using human and animal models, in her later work Mary focused on possible roles of interactions between female sex hormones and vasodilating actions of oxytocin in the perimenopausal problem of ‘hot flashes’ (or ‘hot flushes’) experienced by many women. She faced, but overcame, entrenched gender prejudice during her career; she was the first woman to be elected to the Pharmacological Society, and the first woman appointed to a chair in the Edinburgh Medical School.