Dark-phase melatonin administration does not reduce blood pressure but induces changes in parameters related to the control of the cardiovascular system in spontaneously hypertensive rats.

ABSTRACT: Melatonin is synthesised during the dark phase of the day, and its biosynthesis is inhibited by light. Exogenously supplied melatonin has been reported to have hypotensive effects. However, in animal experiments, melatonin is usually administered in one high dose and blood pressure (BP) is almost exclusively measured by plethysmography during the light phase of the day. We tested the effects of melatonin administration in drinking water during the dark phase of the day at different concentrations (2-45 mg/kg/12 h) for three weeks and telemetrically measured haemodynamic variables in spontaneously hypertensive rats (SHR). We measured gene and protein expression in the hypothalamus, brainstem, kidney and adrenal gland. We did not observe a BP decrease even at the highest melatonin concentrat

SUBMITTER: Mauer Sutovska H 

PROVIDER: S-EPMC12321580 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature