As glyoxylate is part of the degradation circuit of cholecystokinin, this suggests that this neuropeptide might be directly involved in exposure-induced panic attacks.
The tetrapeptide of cholecystokinin (CCK), CCK-4, is known to induce panic attacks in human subjects, while CCK-8 is reported to have a therapeutic effect on schizophrenia symptoms.
Cholecystokinin-tetrapeptide (CCK-4)-induced panic attacks are reportedly attenuated by effective treatment with antipanic antidepressants in patients with panic disorder, but in healthy volunteers such effects are not well studied.
Specifically, there was a significantly lower rate of CCK-4-induced panic attacks in female subjects who had MAO-A longer alleles or 5-HTTLPR short allele gene variants.
This study demonstrated that in contrast to the findings in patients with panic disorder, in CCK-4-sensitive healthy volunteers the treatment with an antipanic SSRI did not cause a reduction of CCK-4-induced panic attacks beyond the effect of placebo.