Deficiency of angiotensin-converting enzyme 2 causes deterioration of cognitive function

Angiotensin-converting enzyme 2 (ACE2), an enzyme that regulates a cellular pathway linked to blood pressure regulation, is found to play an important role in maintaining normal cognitive functions. Masatsugu Horiuchi and his colleagues from the medical school of Ehime University in Japan, using classical behavioral tests, compared the cognitive functions of mice without ACE2 with those of normal mice, and found impaired spatial learning and memory in the former. Among the ACE2-deficient mice, the researchers observed an increased production of free radicals and a decrease of an important learning-related nerve growth factor, which might explain their impaired cognitive functions. The study helps elucidate cognitive effects of the protective arm of the hormone system that regulates blood pressure, with potential applications in the prevention of cognitive decline in diseases such as hypertension and diabetes.