ADCYAP1 and migraine disorder: This assumption is rooted in the observation that PACAP has been demonstrated to induce arterial dilation in rats, and this process appears to be mast-cell dependent.81 Notably, efforts aimed at targeting the conventional receptors for SP (NK1R) and PACAP (PAC1R) 82, 83, have yielded limited success in mitigating pain, including migraine pain.