Dynamic pacing of cell metabolism by intracellular Ca2+ transients

• Published in: The Journal of biological chemistry Vol. 269; no. 44; pp. 27310 - 27314
• Main Authors: Pralong, W F, Spät, A, Wollheim, C B
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 04.11.1994; American Society for Biochemistry and Molecular Biology
• Subjects: Angiotensin II - pharmacology; Animals; Arginine Vasopressin - pharmacology; Calcium - metabolism; Cells, Cultured; Energy Metabolism; Epinephrine - pharmacology; Glucose - metabolism; In Vitro Techniques; Islets of Langerhans - metabolism; Liver - metabolism; Membrane Potentials; NADP - metabolism; Rats; Zona Glomerulosa - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)46986-4

During cell activation, Ca2+, by stimulating the NADH-producing mitochondrial dehydrogenases, triggers the generation of reducing equivalents whereby ATP production is sustained. In cell populations, [Ca2+] changes in the mitochondrial matrix were demonstrated to parallel rapidly those in the cytosol ([Ca2+]i). There is still no indication as to whether metabolic activation follows oscillatory patterns similar to those of [Ca2+]i. Therefore, changes in NAD(P)H were monitored in single pancreatic beta-cells, adrenal glomerulosa cells, and liver cells during oscillatory [Ca2+]i transients. Rapid NAD(P)H and [Ca2+]i oscillations with similar frequency and sensitive both to changes in glucose concentration and to extracellular Ca2+ removal were identified in a subpopulation of pancreatic beta-cells in primary culture. Furthermore, Ca(2+)-dependent oscillatory NAD(P)H formation could be evoked by the pulsatile application of depolarizing [K+], demonstrating the pacing effect of increased [Ca2+]i on beta-cell metabolism. In adrenal glomerulosa cells, angiotensin II, a physiological stimulator of aldosterone production, could be shown to elicit the oscillatory formation of mitochondrial NAD(P)H through frequency modulation of [Ca2+]i transients. In contrast to the two former endocrine cell types, in hepatocytes, [Arg8]vasopressin and epinephrine caused the amplitude modulation of NAD(P)H formation. Taken together, these results provide unprecedented evidence for a cell-specific pacing of metabolism by [Ca2+]i transients coordinated with cell activation and function.