HRH1 and cardiac arrhythmia: It did not inhibit the MAO-A enzyme isoform, as assessedby the fluorometric method detecting the activity of human recombinantMAO-A (Figure 2K).Furthermore, PZ-1922 demonstrated no potential adverseeffects related to its affinity for the adrenergic α1 receptor, adrenergic β1 receptor (which could beassociated with hypertension or arrhythmia), D2 dopaminereceptor (linked to extrapyramidal symptoms and hyperprolactinemia),M1 muscarinic receptor, and H1 histaminic receptor(which could cause sedation).