Isorhynchophylline Regulates the Circadian Rhythm of the Hypothalamus in Spontaneously Hypertensive Rats to Treat Hypertension

Background: The neurotransmitter metabolism in spontaneously hypertensive rats (SHR) is disordered, and these disturbances in neurotransmitter levels can further exacerbate the development of hypertension. Neurotransmitters can affect the expression of circadian clock genes. Objective: To clarify the time-dependent internal mechanism of the imbalance of the target neurotransmitter metabolic rhythm of spontaneously hypertensive rats, the circadian research was carried out by the method of targeted metabolomics and molecular biology technology. Methods: We have explored the mechanism of isorhynchophylline regulating the circadian rhythm through the ERK signaling pathway and thus treating hypertension by detecting the changes of central hypothalamic biological clock rhythm genes after isorhynchophylline intervention, from hypothalamic neurotransmitter rhythmicity. Results: The expression of rhythm genes in normal rats showed a certain rhythm at 6 time points, while the expression of rhythm genes in model rats decreased, and the gene rhythm returned to normal after isorhynchophylline treatment. Cosine analysis of 12 neurotransmitters in hypothalamus showed that there were 6 rhythmic neurotransmitters in the normal group, while in the model group, 4 of the 6 neurotransmitters lost their rhythmicity, and the rhythmicity returned to normal after isorhynchophylline intervention. Compared with the normal group, the expression of ERK protein in the model group increased significantly and decreased after isorhynchophylline treatment. Conclusion: The mechanism of isorhynchophylline treating hypertension is not only the regulation of serum neurotransmitters rhythm, but also acting on rhythm genes in the feedback loop of the central biological clock.