A preovulatory rise of dehydroepiandrosterone in the mare measured by radioimmunoassay.

The study is about the development of a radioimmunoassay procedure to measure the hormone dehydroepiandrosterone (DHA) in nonpregnant horses, noting that DHA concentrations peak right before ovulation.

Development of Radioimmunoassay Procedure

• The research revolves around the development of a radioimmunoassay, a method to measure small amounts of substances, in this case, dehydroepiandrosterone (DHA) in the peripheral serum of nonpregnant mares (adult female horses).
• The radioimmunoassay technique is often used to measure concentrations of hormones, drugs, and other substances in the body. In this instance, it’s used to measure concentrations of DHA, a hormone that’s primarily produced in your adrenal glands, brain, and gonads, pivotal for producing other hormones such as testosterone and estrogen.

Synthesis and Conjugation of Antigen

• The study proceeded with the synthesis and conjugation of the antigen, 3beta-hydroxy-5-androsten-19-al-17-one 19(0-carboxymethyl) oxime. The antigen is needed in an immunological reaction. These antigens are synthesized and characterized for the purpose of the study.
• A specific form of this antigen was developed to measure the presence of DHA in the mares’ serum. In simple terms, they created substances that would react to DHA so that it could be detected and measured.

Identification of DHA levels

• Antisera (the blood serum containing antibodies) against this antigen were developed and characterized, meaning the specifics of how these antisera react against the antigen was studied.
• It was found that the concentrations of DHA were the greatest immediately before ovulation in non-pregnant mares. Ovulation refers to the release of eggs from the ovaries. This may suggest that DHA plays a role in the mare’s ovulation process.