Glutamate oxaloacetate transaminase: a new key in the dysregulation of glutamate in migraine patients

Abstract

Objective: Based on the capacity of the blood-resident enzyme glutamate oxaloacetate transaminase (GOT) to metabolize blood glutamate, our aim was to study the association of GOT activity with serum glutamate levels and clinical parameters in patients with migraine.

Methods: This case-control study included 45 episodic migraine patients (IHS 2004 criteria) and 16 control subjects. We analyzed glutamate and GOT activity in peripheral blood samples obtained during interictal periods and migraine attacks ( N = 15). Frequency, severity, and duration of attacks and time of evolution were also recorded.

Results: Migraine patients showed lower GOT activity than controls (15.2 ± 2.9 vs. 18.7 ± 3.8 U/l) and higher levels of glutamate (153.7 ± 68.6 vs. 121.5 ± 59.2 μM) (all P < 0.05). A negative correlation was found between GOT activity and glutamate levels ( R = -0.493; P < 0.0001) in interictal periods; however, this negative correlation was lost during attacks ( R = -0.026; P = 0.925). During attacks, we found a positive correlation between the time elapsed from attack onset and glutamate levels ( R = 0.738; P < 0.0001), but not for GOT activity ( R = -0.075; P = 0.809).

Conclusions: Migraine patients showed reduced GOT activity and increased levels of blood glutamate levels as compared to control subjects. Furthermore, a negative correlation was found between GOT activity and glutamate levels in interictal periods.

Keywords: Blood; glutamate; glutamate oxaloacetate transaminase; migraine.