The Na^+/H⁺-Exchanger NHE1 Regulates Extra- and Intracellular pH and Nimodipine-sensitive [Ca²⁺]_i in the Suprachiasmatic Nucleus.

ABSTRACT: The central clock in the suprachiasmatic nucleus (SCN) has higher metabolic activity than extra-SCN areas in the anterior hypothalamus. Here we investigated whether the Na⁺/H⁺ exchanger (NHE) may regulate extracellular pH (pHe), intracellular pH (pHi) and [Ca²⁺]_i in the SCN. In hypothalamic slices bathed in HEPES-buffered solution a standing acidification of ~0.3 pH units was recorded with pH-sensitive microelectrodes in the SCN but not extra-SCN areas. The NHE blocker amiloride alkalinised the pHe. RT-PCR revealed mRNA for plasmalemmal-type NHE1, NHE4, and NHE5 isoforms, whereas the NHE1-specific antagonist cariporide alkalinised the pHe. Real-time PCR and western blotting failed to detect day-night variation in NHE1 mRNA and protein levels. Car

SUBMITTER: Cheng PC 

PROVIDER: S-EPMC6478949 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature