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 Katsumata, M. Articles by Dauncey, M. J. Search for Related Content PubMed PubMed Citation Articles by Katsumata, M. Articles by Dauncey, M. J.

---

Article

Growth Hormone Receptor Gene Expression in Porcine Skeletal and Cardiac Muscles Is Selectively Regulated by Postnatal Undernutrition^{1 ,2}

The Babraham Institute, Cambridge CB2 4AT, UK

³To whom correspondence should be addressed.

During mild postnatal undernutrition, growth hormone receptor (GHR) mRNA abundance decreases in liver but increases in longissimus dorsi muscle. We tested the following hypotheses: 1) GHR gene expression is related to the metabolic and contractile characteristics of different muscles, and 2) the GHR response to nutrition depends on muscle type. Eight pairs of littermate pigs were weaned at 3 wk and given an optimal [60 g/(kg·d)] or low [(20 g/(kg·d)] food intake for the next 3 wk. All pigs grew, but at a slower rate in the low food intake group (P < 0.001). Functionally distinct muscles were assessed for GHR mRNA (RNase protection analysis), oxidative myofibers (succinate dehydrogenase histochemistry) and type I slow myofibers (myosin immunocytochemistry). There were striking muscle-specific differences in GHR gene expression (P < 0.001) and in its regulation by nutritional status. Relative expression of GHR mRNA in the optimal food intake group occurred in ascending order as follows: longissimus < diaphragm rhomboideus < cardiac < soleus. There was a positive correlation with the proportion of oxidative myofibers (P < 0.001) but not with type I myofibers (P > 0.10). Compared with the high intake pigs, hepatic GHR mRNA was downregulated in the low intake pigs by 59% (P < 0.01), whereas in the four muscles examined it was upregulated as follows: longissimus, 124% (P < 0.05); rhomboideus, 19% (P > 0.4); soleus, 65% (P < 0.05); cardiac, 51% (P < 0.05). Moreover, the proportion of skeletal muscle fibers with high oxidative capacity was also greater in the low intake group (P < 0.05). We conclude that postnatal GHR gene expression and its regulation by mild undernutrition are related to the metabolic, contractile and specific functional properties of different muscles.

KEY WORDS: • growth hormone receptor • muscle function • postnatal development • pigs • skeletal and cardiac muscle • undernutrition

This article has been cited by other articles:

				I. Pilecka, C. Patrignani, R. Pescini, M.-L. Curchod, D. Perrin, Y. Xue, J. Yasenchak, A. Clark, M. C. Magnone, P. Zaratin, et al. Protein-tyrosine Phosphatase H1 Controls Growth Hormone Receptor Signaling and Systemic Growth J. Biol. Chem., November 30, 2007; 282(48): 35405 - 35415. [Abstract] [Full Text] [PDF]

				M. Katsumata, M. Matsumoto, S. Kawakami, and Y. Kaji Effect of heat exposure on uncoupling protein-3 mRNA abundance in porcine skeletal muscle J Anim Sci, December 1, 2004; 82(12): 3493 - 3499. [Abstract] [Full Text] [PDF]

				M. Katsumata, S. Kawakami, Y. Kaji, R. Takada, and M. J. Dauncey Differential Regulation of Porcine Hepatic IGF-I mRNA Expression and Plasma IGF-I Concentration by a Low Lysine Diet J. Nutr., April 1, 2002; 132(4): 688 - 692. [Abstract] [Full Text] [PDF]

				P. WHITE, K. A. BURTON, A. L. FOWDEN, and M. J. DAUNCEY Developmental expression analysis of thyroid hormone receptor isoforms reveals new insights into their essential functions in cardiac and skeletal muscles FASEB J, June 1, 2001; 15(8): 1367 - 1376. [Abstract] [Full Text] [PDF]