Aromatase gene expression in the stallion.

The research focuses on studying the distribution of the enzyme known as equine aromatase in stallions across various adult tissues. The study indicates that the testis is the primary source of aromatase production in these adult horses, and this is responsible for a high level of estrogen synthesis.

Objective of The Research

• The paper aims to understand the distribution and role of the equine aromatase enzyme in various tissues of an adult stallion. The aromatase enzyme leads to high levels of estrogen production, which this study seeks to understand better.

Methodology

• The research sets out by studying the distribution of equine aromatase in several adult tissues, including the brain, liver, kidney, small intestine, muscle, bulbourethral gland, and testes.
• The presence of aromatase mRNA was detected using RT-PCR primarily in the testis.
• The range of expression was confirmed through ELISA in the testis implant.
• Further verification was performed by immunoblot, which showed a specific protein band in the testis and brain.
• The corresponding aromatase activity was measured by the release of 3H2O from 1beta and 2beta 3H-androstenedione in the testis and brain.

Findings

• The study identified that the primary source of aromatase, among the tissues analyzed, is the testis in an adult stallion.
• The research suggests aromatase gene expression is specifically enhanced in the testis, which is responsible for the high estrogen synthesis observed.
• A study on one colt testis showed lower levels of transcripts, protein, and enzyme activity, indicating that the aromatase enzyme’s regulation happens during development. Therefore, it can be used as a useful marker of testicular function.
• The brain was the secondary organ where both aromatase mRNA and activity were effectively detected. This finding underscores the potential impact of neurosteroids on the behavior, brain function, or central endocrine control in stallions.