Ernst Knobil; Physiologist Studied Hormones, Helped Improve Fertility

Ernst Knobil, 73, a physiologist whose studies of a hormone that influences reproduction led to improved treatment of infertility. Knobil, a professor of physiology at the University of Texas Medical School in Houston, devoted much of his research to understanding the relationship between the hormone-secreting hypothalamus and the reproductive cycle. He and his associates discovered that the hypothalamus, a gland deep in the brain, releases a hormone called LHRH into a special vascular system connected to the pituitary gland, which in turn releases its own ovulation-controlling hormones. This discovery led to the use of an infusion pump to release synthetic hormones into the bloodstreams of infertile women to increase the chance of pregnancy. “We’re finding out that babies really come from the brain,” Knobil said in 1984. The use of the synthetic hormone led to a better than 90% pregnancy rate in countering one common type of infertility. Knobil directed a neuro-endocrinology laboratory at the University of Texas from 1981 to 1997 and was co-editor of the four-volume Encyclopedia of Reproduction and a two-volume work on the physiology of reproduction. Last year he headed a National Research Council panel that examined the impact of hormone-altering chemicals in the environment but reached no conclusion on whether so-called endocrine disrupters commonly found in pesticides, plastics and other products were harmful to people. On April 13 of pancreatic cancer at the Texas Medical Center in Houston.