AJP - Heart AJP: Renal Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 275: H726-H729, 1998;
0363-6135/98 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jeneson, J. A. L.
Right arrow Articles by Portman, M. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jeneson, J. A. L.
Right arrow Articles by Portman, M. A.
Vol. 275, Issue 2, H726-H729, August 1998

Letters to the Editor

J. A. L. Jeneson

R. W. Wiseman, Department of Radiology, University of Washington School of Medicine, Seattle, WA 98195,

M. J. Kushmerick

Departments of Radiology and Physiology and Biophysics and Center for Bioengineering, University of Washington School of Medicine, Seattle, WA 98195,

H. V. Westerhoff

Department of Microbial Physiology, Faculty of Biology, Free University, 1081 HV Amsterdam; and, E. C. Slater Institute, Biocenter, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands,

The following is the abstract of the article discussed in the subsequent letter:

Portman, Michael A., Yun Xiao, Ying Song, and Xue-Han Ning. Expression of adenine nucleotide translocator parallels maturation of respiratory control in heart in vivo. Am. J. Physiol. 273 (Heart Circ. Physiol. 42): H1977-H1983, 1997.---Changes in the relationship between myocardial high-energy phosphates and oxygen consumption in vivo occur during development, implying that the mode of respiratory control undergoes maturation. We hypothesized that these maturational changes in sheep heart are paralleled by alterations in the adenine nucleotide translocator (ANT), which are in turn related to changes in the expression of this gene. Increases in myocardial oxygen consumption (MVO2) were induced by epinephrine infusion in newborn (0-32 h, n = 6) and mature sheep (30-32 days, n = 6), and high-energy phosphates were monitored with 31P nuclear magnetic resonance. Western blot analyses for the ANT1 and the beta -subunit of F1-adenosinetriphosphatase (ATPase) were performed in these hearts and additional (n = 9 total per group) as well as in fetal hearts (130-132 days of gestation, n = 5). Northern blot analyses were performed to assess for changes in steady-state RNA transcripts for these two genes. Kinetic analyses for the 31P spectra data revealed that the ADP-MVO2 relationship for the newborns conformed to a Michaelis-Menten model but that the mature data did not conform to first- or second-order kinetic control of respiration through ANT. Maturation from fetal to mature was accompanied by a 2.5-fold increase in ANT protein (by Western blot), with no detectable change in beta -F1-ATPase. Northern blot data show that steady-state mRNA levels for ANT and beta -F1-ATPase increased ~2.5-fold from fetal to mature. These data indicate that 1) respiratory control pattern in the newborn is consistent with a kinetic type regulation through ANT, 2) maturational decreases in control through ANT are paralleled by specific increases in ANT content, and 3) regulation of these changes in ANT may be related to increases in steady-state transcript levels for its gene.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online