Lysergic acid diethylamide stimulates cardiac human H 2 histamine receptors
Ulrich Gergs, Hannes Jacob, Pauline Braekow, Britt Hofmann, Steffen Pockes, Laura J. Humphrys, Uwe Kirchhefer, Charlotte Fehse, Joachim Neumann
Summary
LSD increased the force of contraction and beating rate in atrial preparations from transgenic mice overexpressing the 5-HT4 receptor and H2-histamine receptor. In human atrial preparations, LSD's effects could be antagonized by cimetidine. The study indicates that LSD has cardiac effects mediated by H2-histamine receptors. These findings highlight the importance of understanding LSD's cardiac effects, particularly as it gains attention for clinical use.
Study at a glance
| Sample size | 6 |
|---|---|
| Population | transgenic mice with cardiomyocyte-specific overexpression of the human 5-HT4 or H2-histamine receptor and human patients during bypass surgery |
| Key finding | LSD leads to H2-histamine receptor mediated cardiac effects in humans. |
Abstract
Abstract Introduction: Lysergic acid diethylamide (LSD) is an artificial hallucinogenic drug. Thus, we hypothesized that LSD might act 5-HT4 serotonin receptors and/or H2 histamine receptors. Methods: We studied isolated electrically stimulated left atrial preparations, spontaneously beating right atrial preparations, and spontaneously beating Langendorff-perfused hearts from transgenic mice with cardiomyocyte-specific overexpression of the human 5-HT4 receptor (5-HT4-TG) or of the H2-histamine receptor (H2-TG). For comparison, we used wild type littermate mice (WT). Finally, we measured isometric force of contraction in isolated electrically stimulated muscle strips from the human right atrium obtained from patients during bypass surgery. Results: LSD (up to 10 µM) concentration dependently increased force of contraction and beating rate in left or right atrial preparations from 5-HT4-TG (n=6, p<0.05) as a partial agonist in 5-HT4-TG atrial preparations. The inotropic and chronotropic effects of LSD were antagonized by 10 µM tropisetron in 5-HT4-TG. In contrast, LSD (10 µM) increased force of contraction and beating rate in left or right atrial preparations, from H2-TG as a full agonist. After pre-stimulation with cilostamide (1 µM), LSD (10 µM) increased force of contraction in human atrial preparations (n = 6, p < 0.05). The contractile effects of LSD in human atrial preparations could be antagonized by by 10 µM cimetidine. Conclusion: LSD leads to H2-histamine receptor mediated cardiac effects in humans. Significance: LSD is undergoing a revival in clinical studies. New indications for LSD especially in psychiatric patients are being found. Hence, there is a clinical need to understand its cardiac effects and possibly cardiac side effects better. The present work uses a translational approach to address this research need.