Angiotensin converting enzyme in the toad Bufo arenarum

Area of Science:

• Comparative physiology
• Biochemistry

Background:

• Angiotensin converting enzyme (ACE) plays a crucial role in cardiovascular regulation in vertebrates.
• Investigating ACE activity in amphibians like the South American toad (Bufo arenarum) can provide insights into its evolutionary conservation and diverse physiological functions.

Purpose of the Study:

• To determine the presence and distribution of Angiotensin converting enzyme activity (ACEA) in various tissues and serum of the South American toad (Bufo arenarum).
• To investigate the effect of specific inhibitors on ACEA in this species.

Main Methods:

• Homogenates of serum, kidney, whole skin, and isolated epithelia from Bufo arenarum were prepared.
• ACEA was measured in these homogenates.
• The effects of ACE inhibitors (captopril, teprotide) and EDTA on ACEA were assessed.

Main Results:

• ACEA was detected in the serum, kidney, whole skin, and isolated epithelia of Bufo arenarum.
• Kidney homogenates exhibited significantly higher ACEA compared to whole skin or isolated epithelia.
• Captopril, teprotide, and EDTA significantly reduced ACEA in the tested samples.

Conclusions:

• The South American toad possesses ACEA in its serum and various tissues, notably higher in the kidney.
• The observed inhibition by captopril, teprotide, and EDTA confirms the enzymatic nature of the activity.
• The findings suggest potential physiological roles for ACEA in Bufo arenarum, warranting further investigation.