The role of smooth muscle cell hypertrophy, hyperploidy, and hyperplasia in medial hypertrophy of mesenteric resistance vessels of 107- to 111-day-old spontaneously hypertensive rats (SHR) was examined using a combination of morphometric, biochemical, and immunological techniques. Mesenteric arteries were classified on the basis of branching order for comparative purposes. Branch level I vessel...

Anti-inflammatory strategies are often used to reduce muscle pain and soreness that can result from high-intensity muscular activity. However, studies indicate that components of the acute inflammatory response may be required for muscle repair and growth. The hypothesis of this study was that cyclooxygenase (COX)-2 activity is required for compensatory hypertrophy of skeletal muscle. We used t...

In animals and humans, intestinal muscular hypertrophy has only been observed in the small intestine, and this appears to be the first report of the disease affecting the large intestine. A rare case of primary muscle hypertrophy of the colon was found during the necropsy of a male, 3-year-old, mixed breed cat that died due to poisoning by carbamate. The necropsy revealed that the entire colon ...

The insulin-like growth factors (IGF-I and IGF-II), working through the type 1 IGF receptor (IGF-1R), are key mediators of skeletal muscle fiber growth and hypertrophy. These processes are largely dependent on stimulation of proliferation and differentiation of muscle precursor cells, termed myoblasts. It has not been rigorously determined whether the IGFs can also mediate skeletal muscle hyper...

Background and Objectives: The aim of the present study was to investigate effectsof a single sessionof eccentric or concentric resistance exercise on relative expression of BDNF, PAX7 and IGF-1 in healthy participants. Materials and Methods: In a field trial, ten healthy young men were randomly assigned into two equal groupsof concentric and eccentric contractions. Isokinetic contraction prot...

PURPOSE To determine relationships between post-exercise changes in systemic [testosterone, growth hormone (GH), insulin like grow factor 1 (IGF-1) and interleukin 6 (IL-6)], or intramuscular [skeletal muscle androgen receptor (AR) protein content and p70S6K phosphorylation status] factors in a moderately-sized cohort of young men exhibiting divergent resistance training-mediated muscle hypertr...

PURPOSE OF REVIEW To highlight recent breakthroughs and controversies in the use of myoblast models to uncover cellular and molecular mechanisms regulating skeletal muscle hypertrophy and atrophy. RECENT FINDINGS Myoblast cultures provide key mechanistic models of the signalling and molecular pathways potentially employed by skeletal muscle in-vivo to regulate hypertrophy and atrophy. Recentl...

Myostatin, which is a member of the TGF-beta superfamily, is a negative regulator of skeletal muscle formation. Double-muscled Piedmontese cattle have a C313Y mutation in myostatin and show increased skeletal muscle mass which resulted from an increase of myofiber number (hyperplasia) without that of myofiber size (hypertrophy). To examine whether this mutation in myostatin gene affects muscle ...

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha 4 (PGC-1α4) is a protein isoform derived by alternative splicing of the PGC1α mRNA and has been shown to promote muscle hypertrophy. We show here that G protein-coupled receptor 56 (GPR56) is a transcriptional target of PGC-1α4 and is induced in humans by resistance exercise. Furthermore, the anabolic effects of PGC-1α4 in cul...

Hypertrophy From Apical Hypertrophic Cardiomyopathy To the Editor: We read with interest the article by Reddy et al1 regarding a case with apical hypertrophic cardiomyopathy. The authors said that the 2D echocardiograph obtained from this patient indicated hypertrophy of the apex and that 201-Tl scintigraphic imaging demonstrated an increased count in the apical segment. However, because there ...