Besides the brain, which of the following organs is known to have dopa carboxylase?

Dopa carboxylase, also known as aromatic L-amino acid decarboxylase, is an enzyme involved in the synthesis of neurotransmitters such as dopamine. While the primary site of dopa carboxylase activity is in the central nervous system, specifically in the brain, it is also found in certain peripheral organs.

The lungs are known to contain dopa carboxylase, which can contribute to local production of dopamine and potentially affect lung function and vascular responses. This peripheral activity is significant because it highlights the role of dopamine beyond its traditional association with the brain, suggesting a potential influence on various physiological processes.

In contrast to the lungs, the other organs listed—skin, spleen, and pancreas—have not been recognized as sites where dopa carboxylase activity occurs significantly. While they may have other important physiological roles and enzymatic functions, they do not contribute to the local production of dopamine in the same way as the lungs do, making the lungs the correct answer.