From pregnancy to potency, hormones are involved in regulating basic body functions. It is, therefore, often crucial to know whether these essential substances, which may be present in extremely low concentrations, are performing properly.
Commonly used diagnostic tests can't give us an answer: They measure only hormone levels, not activity. A new approach developed at the Weizmann Institute and described in the upcoming issue of Endocrine addresses this problem.
To evaluate hormonal function, it is necessary to determine whether the hormone can bind to specific receptors on target cells, and whether this binding causes the cells to produce certain substances. Such testing is complicated because the natural target cells are usually short-lived and have relatively few appropriate receptors.
Prof. Abraham Amsterdam and his colleagues in the Molecular Cell Biology Department have overcome this difficulty by genetically engineering immortal ovarian cells (which reproduce endlessly in laboratory conditions) and equipping the cells with large numbers of suitable receptors.
These cells were used to test the biological activity of gonadotropin hormones, involved in regulating ovulation, sperm maturation and sexual development. Three major indicators were successfully assessed: binding to cells, production of a vital chemical messenger called cyclic AMP, and the resultant release of progesterone, a product of ovarian cells that is essential for maintaining uninterrupted pregnancy.
The scientists have also adapted their new method for testing the activity of catecholamines, the group of hormones that includes adrenalin, which regulates heart beat and blood pressure.
Medical diagnosis is not the only potential application of the new test, which has yet to be developed commercially. It holds promise for use in a variety of fields, including the hormonal testing required for animal breeding.
The team of Prof. Amsterdam, who holds the Joyce and Ben B. Eisenberg Chair of Molecular Endocrinology, included Dr. Ngounder Selvaraj and Ada Dantes, along with Dr. Rina Limor and Prof. Avraham Golander of the Tel Aviv Medical Center. Funding for this research was provided by the Israel Ministry of Science and the Dr. Josef Cohn Minerva Center for Biomembrane Research at the Weizmann Institute.
The Weizmann Institute of Science is a major center of scientific research and graduate study located in Rehovot, Israel.