Articles       405        Is there an explicit correspondence between physiological and morphological features in amphibian twitch
                                  skeletal muscle fibres?
                                  E Lipská, M Novotová, T Radzyukevich and G Nasledov     [Full text pdf 1.93Kb]

                    413        Dynamic cardiomyoplasty and aortomyoplasty: the Buenos Aires experience
                                  JC Trainini     [Full text pdf 28Kb]

                    419        Is hypertrophy limited in elderly muscle fibers? A comparison of elderly and young strength-trained men
                                  RS Hikida, S Walsh, N Barylski, G Campos, FC Hagerman and RS Staron    [Full text pdf 655Kb]

                    429        Endothelins in pulmonary development
                                  VP Krymskaya and RA Panettieri     [Full text pdf 219Kb]

                    441        Exercise-induced hypoxia and structural and metabolic adaptation of skeletal muscle
                                  TL Nemirovskaya, BS Shenkman, VB Koshelev     [Full text pdf 33.4Kb]

                    447        Proliferating myoblasts transfected with FasL cDNA can escape from apoptosis
                                  E Giurisato, M Sandri, C Sandri, R Zoin, GG Ancona and M Cantini    [Full text pdf 750Kb]
 
 

Is there an Explicit Correspondence Between Physiological and Morphological Features in Amphibian Twitch Skeletal Muscle Fibres?

Elena Lipská, Marta Novotová, Tatiana Radzyukevich(1) and Grigory Nasledov(1)

Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava,

Slovak Republic and (1) I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St.-Petersburg, Russia
 

The contractile characteristics, fatiguability, and ultrastructure were examined in individual twitch skeletal muscle fibres dissected from the iliofibularis muscle of frog Rana temporaria in order to define if an explicit correspondence exists between physiological and morphological features in different types of muscle fibres. Three groups of twitch fibres were distinguished in the study according to their fatiguability: fatigue resistant (FR), moderately fatigued (MF) and easily fatigued (EF). The ultrastructural features such as regularity of striation, the density of myofibrils, Z-band morphology, mitochondrial and lipid droplet contents, which are commonly used to distinguish skeletal muscle fibre types, are shown to correlate with physiological properties verifying FR, MF and EF fibre groups only in a statistical way. In individual fibres, however, there is no strong correlation between contraction speeds, fatiguability, and ultrastructural features. The conclusion is made that ultrastructural features of individual fibres may not be used to predict the physiological properties attributed to particular fibre type.

Key words: amphibian skeletal muscle, twitch fibres, fatiguability, ultrastructure.

Basic Appl. Myol. 8 (6): 405-412, 1998

Address correspondence to:
Prof. Grigory Nasledov, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Thorez av., 44, 194223 St.-Petersburg (Russian Federation), fax +007 812 5523012, Email nasledov@ief.spb.su.

Dynamic Cardiomyoplasty and Aortomyoplasty: the Buenos Aires Experience

Jorge C. Trainini

Hospital Presidente Perón, Buenos Aires, Argentina
 

The aim of the present study is to evaluate results obtained after applying dynamic cardiomyoplasty or Aortomyoplasty to patients with dilated cardiomyopathy and severe ventricular dysfunction (Functional Class III-IV, New York Heart Association).A dynamic cardiomyoplasty procedure was performed in 15 patients with a mean age of 59.2 ± 6.4 years. Despite the medical treatment with inhibitors of the converted enzyme of vasodilators, these patients required 2.2 ± 0.7 hospitalizations/patient/year owing to congestive heart failure in the year before dynamic cardiomyoplasty was applied. In 8 patients the etiology of the cardiomyopathy was idiopathic, ischemic-necrotic in 6 and Chagas’disease in the other.Hemodynamic studies were done preoperatively in all patients and every six months postoperatively.Twelve patients had a follow-up for two years. The following values related to two-years evaluation improved significantly in comparison with baseline: Functional Class (1.7 ± 0.6 versus 3.06 ± 0.2); radionuclide left ventricular ejection fraction (29.7% ± 5 versus 23.6% ± 3); fractional shortening (20.6% ± 5 versus 15.6% ± 4). Walking test values increased from 332 meters ± 127 to 421 meters ± 102. Left ventricular diastolic diameter remained unchanged (72.7 mm ± 7 versus 72.3 mm ± 8).Improvement was observed in functional capacity and left ventricle systolic function parameters two years after cardiomyoplasty.Aortomyoplasty: six patients were included with mean age of 52 years and a Functional Class III-IV. One patient died two months later (ventricular arrhythmia) before completing the stimulation protocol. The other 5 patients improve the Functional Class with a value of I-II at 12 months postoperative average.

Key words: aortomyoplasty, cardiomyoplasty, latissimus dorsi muscle, skeletal muscle, cardiomyopathy.

Basic Appl. Myol. 8 (6): 413-418, 1998

Address correspondence to:
Dr. Jorge Trainini, Hospital Presidente Perón, Anatole France 773 – (1870) Avellaneda, Provincia Buenos Aires, Argentina, fax 0054 1 302 3810.

Is Hypertrophy Limited in Elderly Muscle Fibers? A Comparison of Elderly and Young

Strength-Trained Men

Robert S. Hikida, Seamus Walsh, Nicole Barylski, Gerson Campos, Fredrick C. Hagerman and Robert S. Staron

Department of Biomedical Sciences and Department of Biological Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
 
 

To investigate the capacity to hypertrophy and the satellite cell populations to change with age, the nucleo-cytoplasmic relationships and satellite cells were compared in skeletal muscles of young and elderly men before and after strength training. Vastus lateralis muscle biopsies were taken before and after 8 (young) or 16 weeks (elderly men) of strength training and compared to muscle from untrained men. The young men had more myonuclei in type II fibers than in type I, and the cytoplasm per nucleus was smaller. As muscle fibers hypertrophied with strength training, the larger cross-sectional area was matched by increasing nuclear numbers, maintaining a constant nucleus-to-cytoplasm ratio. The numbers of myonuclei were similar in elderly and young muscles, and strength training increased both, but not significantly. Myonuclear number was related to cross-sectional area in young untrained and trained muscles, but no relationship was found in untrained elderly men. With training, this relationship was restored in the elderly muscles. The relative increase in cross-sectional area in elderly muscles was similar to the young, but the elderly muscles began with such small fibers, that the hypertrophied fibers in the trained elderly muscles reached the size of untrained young muscle fibers. The results suggest that the increase in myonuclear number accompanies and is proportional to fiber hypertrophy in the young, but it is still unclear to what extent this occurs in the elderly. The percentage of satellite cells did not differ between young and elderly muscles. These satellite cells, responsible for contributing to myonuclear increase, did not decrease in numbers with aging.

Key words: muscle aging, muscle growth, strength training, nucleo-cytoplasmic relationships.

Basic Appl. Myol. 8 (6): 419-427, 1998

Address correspondence to:
Robert S. Hikida, Ph.D. Department of Biomedical Sciences, Ohio University College of Osteopathic Medicine, Athens, Ohio 45701. U.S.A., phone (740) 593 2323, fax (740) 597 2778, Email hikida@ohiou.edu.

Endothelins in Pulmonary Development

Vera P. Krymskaya and Reynold A. Panettieri, Jr.

Pulmonary and Critical Care Division, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia
 
 

Endothelins (ETs), first discovered as potent vasoconstrictors, are a family of polypeptides with a wide range of activities in the airvays and pulmonary vascular system. Synthesized by respiratory epithelium and by pulmonary vascular endothelium, ETs, as a potent bronchoconstrictors and mitogens, may play a role in the pathogenesis of pulmonary hypertension and bronchial asthma. ETs are a part of a complex homeostatic mechanism in mature airways however, a critical biological role of ETs have been implicated of modulating the development of the lung and vasculature, of Hirschsprung’s disease, of asthma and potentially pulmonary hypertension. Lack of ET-1, ET_A receptor or endothelin-converting enzyme-1 (ECE-1), as result of complete knockout of the ET-1, ET_A receptor or ECE-1 genes, induces abnormalities of the pharyngeal-arch-derived craniofacial tissues and death by respiratory failure at birth. In humans and mice normal development of epidermal melanocytes and enteric ganglion neurons are affected by ET-3 and ET_B receptor genes. Mutations in the ET_B receptor gene mapped to chromosome 13 resulted in development of Hirschsprung disease in humans. Taken together, compelling evidence suggests that ET-1 may contribute to smooth muscle growth, vasculature, airways remodeling as well as modulate cardiopulmonary development.

Key words: growth, lung, respiratory, vascular and airway remodeling, signal transduction.

Basic Appl. Myol. 8 (6): 429-440, 1998

Address correspondence to:
Reynold A. Panettieri, Jr., M.D., Pulmonary and Critical Care Division, Room 805 East Gates Building, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104-4283, USA, phone (215) 349 5480, fax (215) 349 5172, Email rap@mail.med.upenn.edu.

Exercise-induced Hypoxia and Structural and Metabolic Adaptation of Skeletal Muscle

Tatiana L Nemirovskaya^(1,2), Boris S. Shenkman⁽²⁾, Vladimir B. Koshelev⁽¹⁾

(1) Moscow State University, Faculty of Basic Medicine, Laboratory of Pathophysiology, Vorobiovii Gori and (2) Institute of Medical and Biological Problems, Department of Sensory-Motor Physiology, Moscow, Russia
 

We hypothesised that elevated oxygen concentration during exercise on rats exhibits smaller muscle structural and metabolic adaptations of skeletal muscles than rats under the same training protocol in normoxia. Changes in m. tibialis anterior after 6-week training by swimming under hyperoxic condition (SO) were compared with those trained in normoxia (SN) and sedentary control rats (C). Capillary-to-fibre ratio was increased in SO and SN group as compared to C. The cross-sectional area was significantly increased in fast glycolytic (FTb) fibres of SO and SN but not in FTa fibres. Myoglobin (MG) concentration in SN was 21% higher in the fast oxidative (FTa) fibres, as well the succinate dehydrogenase (SDH), cytochrome c oxidase (cyt.c) and a -glycerophosphate dehydrogenase (a -GPDH) activity were 18, 56 and 45% higher respectively, than in C group (p < 0.05). Cyt.C and a -GPDH activity in FTb fibres in SN were 69 and 40% higher respectively than in C animals (p < 0.05). No significant changes were found either in SDH or a -GPDH activities or MG content in SO animals compared to the C. In conclusion, hypoxia arising in muscles during training stimulates those changes that promote better substrate and oxygen supply to muscles and better oxygen transport within fibres. Apparently, initiation of capillary growth is determined by factors other than hypoxia.

Key words: hyperoxia, skeletal muscle fibres, oxidative potential, capillary supply.

Basic Appl. Myol. 8 (6): 441-445, 1998
Address correspondence to:
Tatiana L. Nemirovskaya, Laboratory of Pathophysiology, Faculty of Basic Medicine, Moscow State University, 119899,Vorobiovii Gori, Moscow, Russia.

Proliferating Myoblasts Transfected with FasL cDNA Can Escape from Apoptosis

Emanuele Giurisato, Marco Sandri⁽¹⁾, Claudia Sandri⁽¹⁾, Riccardo Zoin, Gina G. Ancona and Marcello Cantini

CRIBI Center, Department of Biomedical Sciences and (1) CNR Unit for Muscle Biology and Physiopathology, Department of Biomedical Sciences, University of Padova, Padova, Italy
 
 

An important but all too often neglected aspect of successful gene therapy is the attenuation or elimination of the local inflammatory response and immune reaction against transferred DNA products and cell transplantation. Expression of the FasL protein, either constitutively or after induction in certain cells, induces apoptosis when it interacts with the Fas cell-surface receptor (APO1, CD95) and the interaction Fas-FasL on T cells is thought to play a major role in the maintenance of immunological homeostasis and peripheral tolerance. Recently attention has focused on the creation of loci of immune privilege (FasL overexpressing loci) where transfected cells can be placed. During attempts to produce myotubes expressing the apoptosis-inducing FasL protein under the control of a CMV promoter, mainly myoblasts were unable to survive the initial transfection. Investigation of the presence of Fas led us to determine that the mRNA for Fas is upregulated during differentiation program of myoblasts corresponding to the peak of cell death in transfected cells. When the cultures are prolonged, some myoblasts can survive and proliferate and are able to form some FasL positive myotubes. Our findings shed light on the conflicting results obtained by two recent studies on FasL engineered myoblasts and open new perspectives regarding the possibility to induce forced expression of FasL in muscle cells.

Key words: gene therapy, myoblasts, FasL, immuno-privilege.

Basic Appl. Myol. 8 (6): 447-451, 1998

Address correspondence to:
M. Cantini CRIBI Center, Department of Biomedical Sciences, University of Padova, viale Colombo 3, 35231 Padova, Italy. phone +39 498276068, fax +39 49 8276049, Email cantini@civ.bio.unipd.it.