QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nakajima, H. Articles by Sawada, T. Search for Related Content PubMed PubMed Citation Articles by Nakajima, H. Articles by Sawada, T.

---

Research Communication

Carnitine Import to Isolated Hepatocytes and Synthesis Are Accelerated in Pivalate-Treated Rats¹

Department of Pediatrics, Kyoto Prefectural University of Medicine, Kajii-cho Hirokoji Kawaramachi Kamigyo-ku, Kyoto 602, Japan

²To whom correspondence should be addressed at Department of Pediatrics, Social Insurance Kyoto Hospital, Shimofusa-cho Koyama Kita-ku, Kyoto 603-8151, Japan. E-mail: zenro{at}ped.kpu-m.ac.jp

To investigate the effect of pivalate on carnitine import and carnitine synthesis in the liver, we measured carnitine uptake in isolated rat hepatocytes with L-[¹⁴C] carnitine and concentrations of free carnitine, -butyrobetaine and acylcarnitines using tandem mass spectrometry. Hepatocytes from rats treated with 20 mmol/L of pivalate for 4 wk had greater L-[¹⁴C] carnitine uptake than those of unsupplemented rats after 5, 10, 30 and 90 min. Addition of 1 mmol/L of pivalate or 1 mmol/L of pivaloylcarnitine to control cell suspensions did not affect L-[¹⁴C] carnitine uptake. The K_m values for L-[¹⁴C] carnitine uptake for pivalate-treated rats were significantly lower than control (2.9 ± 0.7 mmol/L for pivalate-treated rats, 6.2 ± 1.1 mmol/L for controls). The concentration of free carnitine was not reduced in the liver of pivalate-treated rats, whereas the concentrations of acetylcarnitine and -butyrobetaine were significantly lower than controls. In the heart and muscle the concentration of free carnitine was significantly lower and that of -butyrobetaine was higher than controls. These results suggest that carnitine transport from plasma into the liver and synthesis in the liver are accelerated in rats with secondary carnitine deficiency induced by the administration of pivalate.

KEY WORDS: • pivalate • carnitine • hepatocytes • tandem mass spectrometry • rats

This article has been cited by other articles:

				A. Mancinelli, A. M. Evans, R. L. Nation, and A. Longo Uptake of L-Carnitine and Its Short-Chain Ester Propionyl-L-carnitine in the Isolated Perfused Rat Liver J. Pharmacol. Exp. Ther., October 1, 2005; 315(1): 118 - 124. [Abstract] [Full Text] [PDF]

				E. P. Brass Pivalate-Generating Prodrugs and Carnitine Homeostasis in Man Pharmacol. Rev., December 1, 2002; 54(4): 589 - 598. [Abstract] [Full Text] [PDF]