After heart attack in rats, Semax reduced the abnormal regrowth of sympathetic nerve fibers into the ventricular wall of the heart — a process that can contribute to dangerous arrhythmias during recovery. The peptide had no effect on the density of beta-adrenergic receptors in heart tissue. This suggests Semax may help normalize cardiac nerve remodeling after a heart attack without broadly altering the heart's receptor landscape.
Gavrilova, S A; Markov, M A; Berdalin, A B; Kurenkova, A D; Koshelev, V B