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Biomedical subjects

R L Moore

Publications and source records attributed to R L Moore.

At least 91 records · Page 5Linked to original sources
PubMed1985

Myosin light chain kinases and myosin phosphorylation in skeletal muscle.

Myosin light chain kinases appear to exist as a family of tissue- and species-specific isozymes. The skeletal muscle kinases, although differing widely in molecular weight among vertebrate species, are catalytically similar and antigenically related. The smooth muscle kinases are catalytically and antigenically distinct from the skeletal muscle kinases. The functional basis for the existence of myosin light chain kinase isozymes has not been determined. Phosphorylation of fast-twitch skeletal muscle myosin P-light chain occurs at physiologically relevant contraction frequencies and durations, and the extent of P-light chain phosphorylation correlates with enhancement of isometric twitch tension in fast-twitch muscle under a variety of experimental conditions. Phosphorylation of myosin P-light chain in vertebrate fast-twitch skeletal muscle may play a modulatory role in calcium regulation of muscle contractility.

Animals↗
PubMed1985

Adaptive response of hypertrophied skeletal muscle to endurance training.

The response of hypertrophied soleus and plantaris muscle of rats to endurance training was studied. Hypertrophy was produced by bilateral extirpation of the gastrocnemius muscle. A 13-wk training program of treadmill running initiated 30 days after removal of the gastrocnemius muscle accentuated (P less than 0.01) the hypertrophy. Succinate dehydrogenase activities of the enlarged muscles of sedentary rats were similar to those of normal animals, as were the increases associated with training. Phosphorylase and hexokinase activities were unaltered as a result of the experimental perturbations. Rates of glycogen depletion during exercise were lower (P less than 0.01) in the liver and soleus and plantaris muscles of endurance-trained animals. No difference existed in the rate of glycogen depletion of normal and hypertrophied muscle within the sedentary or trained groups. These data demonstrate that extensively hypertrophied muscle responds to training and exercise in a manner similar to that of normal muscle.

Adaptation, Physiological↗
PubMed1985

Dynamic exercise training in foxhounds. II. Analysis of skeletal muscle.

The purpose of this study was to determine whether 8-12 wk of endurance training produces biochemical and histochemical adaptations in skeletal muscle in foxhounds. Analyses were performed on samples removed from gastrocnemius, triceps, and semitendinosus muscles of foxhounds before and after a treadmill running program. Biochemical analysis showed that training did not alter the activities of phosphofructokinase, beta-hydroxyacyl-CoA dehydrogenase, succinate dehydrogenase, or total phosphorylase. Histochemical analysis of myofibrillar actomyosin ATPase demonstrated three distinct classes of type II fibers and one type I fiber in the semitendinosus and triceps muscles and two type II and two type I fibers in the gastrocnemius muscle. Fiber type distribution and oxidative and glycolytic potentials, as indicated by nicotinamide adenine dinucleotide tetrazolium reductase or alpha-glycerophosphate dehydrogenase staining intensity, were unaltered by training. Similarly, capillary density, capillary-to-fiber ratios, and capillary area-to-fiber area ratios did not change with training. Thus, unlike humans and other mammals (i.e., rat), these foxhounds did not manifest biochemical or histochemical adaptations in skeletal muscle as the result of endurance training. This is consistent with the results of the study in which endurance training produced a 27% increase in maximal cardiac output and a 4% increase in maximal arteriovenous O2 extraction in foxhounds.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1984

Myosin light chain phosphorylation in fast and slow skeletal muscles in situ.

The physiological properties of contraction-induced phosphate incorporation into the phosphorylatable light chain (P-light chain) of myosin were examined in fast-twitch white, fast-twitch red, and slow-twitch skeletal muscles in situ. Neural stimulation of rat gastrocnemius muscles between 0.5 and 100 Hz produced an increase in the phosphate content of the P-light chain from the white portion of the muscle, and the rate of P-light chain phosphorylation was frequency dependent. The extent of phosphorylation of P-light chain from the fast-twitch red portion of the gastrocnemius muscle was less. In contrast to fast-twitch skeletal muscle, only high-frequency stimulation (30-100 Hz) produced a small increase in the phosphate content of P-light chain from the slow-twitch soleus muscle. Fast white muscle contained 2.2 and 3.5 times more myosin light chain kinase activity than did the fast red and slow muscle, respectively. The rate of P-light chain dephosphorylation was four times faster in slow muscle than in fast white muscle. Thus the greater extent of phosphorylation of P-light chain in fast-twitch white skeletal muscle fibers may be due in part to the presence of more kinase and less phosphatase activities. Isometric twitch tension potentiation was correlated to the extent of phosphorylation of P-light chain from fast white muscle. The physiological consequences of P-light chain phosphorylation are likely to be of greatest importance in fast-twitch white muscle.

Animals↗
PubMed1983

Fiber number and size in overloaded chicken anterior latissimus dorsi muscle.

The relative contribution of increases in fiber area and number was evaluated in the chicken anterior latissimus dorsi (ALD) muscle in which enlargement was induced by hanging a weight on one wing. ALD muscles from wings to which weights had been attached for periods ranging from 6 to 65 days weighed an average of 105% (range 22-225%) more than control muscles. Total muscle fiber number, determined by direct counts after nitric acid digestion and fiber dissection, and the frequency of branched fibers were unchanged by muscular enlargement. Fiber cross-sectional area was greater (P less than 0.01) in the enlarged muscles. A close relationship existed (r = 0.78) between actual muscle weight and weight calculated as the product of fiber volume, total fiber number, and muscle density for the control and enlarged muscles. Histochemical staining revealed a conversion of type IIa to type I fibers in the stretched muscles. These results support the concept that skeletal muscle enlargement in response to chronic overload is produced by hypertrophy of preexisting fibers and not be a formation of new fibers.

Animals↗
PubMed1982

Response of ventilatory muscles of the rat to endurance training.

The effect of endurance training on the oxidative and glycolytic potentials of the diaphragm and intercostal muscles of rats has been studied. Training consisted of treadmill running (28 m/min, 60 min/day, 5 days/wk) for periods ranging from 8-26 weeks. Exercise of similar duration and intensity produced a glycogen depletion in the diaphragm and intercostal muscles of nontrained rats. Oxidative potential was estimated from the activity of the mitochondrial marker enzyme succinate dehydrogenase (SDH). The activities of phosphorylase (PHOS), hexokinase (HK), and lactate dehydrogenase (LDH) were determined as well as the distribution of the LDH isozymes. SDH activity averaged 44 (42-51) and 17 (10-22)% (P less than 0.0l) greater in the plantaris and diaphragm muscles, respectively, after 8-12 weeks of endurance running as compared to the sedentary animals. There was no change in the SDH activity of the intercostal muscles or in the activities of the glycolytic enzymes. There was also no change in the distribution of the isozymes of LDH. Extending the duration of the training program to 26 weeks did not produce any additional alteration in the magnitude of the adaptation observed after the initial training period. Comparative studies of different types of muscles demonstrated that the diaphragm, although having a fiber composition somewhat similar to that of a fast-twitch skeletal muscle, has a metabolic profile that is intermediate between pure slow twitch skeletal muscle and cardiac muscle.

Adaptation, Physiological↗
PubMed1982

Effect of training on beta-adrenergic receptor number in rat heart.

Female Sprague-Dawley rats were subjected to endurance-training programs, and the effect of training on myocardial beta-adrenergic receptor number, receptor-binding characteristics, and adenylate cyclase (AC) activities associated with the receptor were examined. Training produced a 45% (P less than 0.01) increase in the succinate dehydrogenase activity of the plantaris muscle. Specific (-)-[3H]dihydroalprenolol (DHA)-binding data were subjected to Scatchard plot analysis to quantify beta-adrenergic receptor number and DHA-binding characteristics of myocardial membranes. The DHA concentrations at which 50% of the total binding sites were occupied were similar for membranes from sedentary (1.95 +/- 0.51) and trained (1.59 +/- 0.34 nM) groups. Total DHA-binding sites of membranes from control (91.6 +/- 13.3) and trained (83.1 +/- 7.6 fmol/mg) groups were also similar. Basal and maximally stimulated AC activities were also unchanged by endurance training. Fluoride-stimulated AC activities of crude homogenate and 10,000 g fractions decreased 47 and 49%, respectively, with training. No differences were observed in a 40,000 g fraction. The specific activities of a ouabain-sensitive Na+-K+-ATPase (a sarcolemmal membrane marker) of crude homogenate, 10,000 g, and 40,000 g membrane fractions were similar. These data indicate that training produces no detectable difference in the potential for adrenergic responses at the receptor level.

Adenylyl Cyclases↗
PubMed1982

Acute fasting and fiber number in rat soleus muscle.

The influence of fasting on fiber number in the soleus muscle (SM) of weanling male and female rats was investigated. For female rats, comparisons were made among groups of animals fed normally, rats fasted and then fed until prefast body weight was regained, and animals that grew to maturity. For male rats, comparisons were made only between control and fasted groups. Prior to the experimental treatments the SM was surgically removed from one leg. There was a 40% loss in body weight after fasting. Although major weight losses occurred in most muscles and organs, there was no change in the SM. Over the same period SM weight increased 31% in normal animals. Total fiber number (direct counts after nitric acid digestion) was unaltered by the treatments. Although wide variation existed between animals, total fiber number between legs for the same animal was closely correlated (r = 0.98). SM weight for male rats calculated from fiber length, cross-sectional area, and total fiber number could account for from 91 to 99% of the total muscle weight. There was no change in fiber number from weaning to maturity. It is concluded that fiber number is unchanged by fasting or during normal maturation.

Animals↗
PubMed1981

Attachment and rosette formation by hyphomicrobia.

The processes of reversible and irreversible sorption of Hyphomicrobium sp. strain ZV580 to solid surfaces was investigated with the use of swarmer cell populations. Various compounds and physical conditions were examined for their effect on the cell-cell interactions which lead to the formation of rosette-like cell aggregates. The monosaccharides galactose and mannose were able to completely inhibit rosette formation. Concanavalin A and chloramphenicol were also able to prevent rosette formation, and both trypsin and pronase caused the disassociation of rosettes. The results indicate that the adhesin is a glycoprotein or a peptido-polysaccharide and that the flagellum may act as a vehicle for the transport of this adhesin from the cell to a surface.

Journal Article↗
PubMed1981

Muscular enlargement and number of fibers in skeletal muscles of rats.

The effect of muscular enlargement produced by surgical ablation of a synergist and the combination of synergist ablation and exercise on the number of fibers in the soleus (S), plantaris (P), and extensor digitorum longus (EDL) muscles of the rat was studied. The number of fibers per muscle was determined by direct counts of individual fibers dissected from HNO3-treated muscles. Ablation of a synergist produced average enlargements of about 25, 45, and 29% for the S, P, and EDL muscles, respectively. Exercise and synergist ablation produced increases in wet weight to about 44 and 88% for the S and P muscles, respectively, whereas no further increases were observed in the EDL muscles. Intra-animal comparisons revealed that no differences existed for total fiber number or the incidence of fibers with bifurcations between the enlarged and contralateral control muscles. The difference in dry weight of fibers from the enlarged as compared with control muscles was closely correlated to differences in total muscle wet weight. These data demonstrate that hypertrophy rather than hyperplasia was responsible for increases from 10 to over 100% in the weight of skeletal muscles.

Animals↗
PubMed1980

Continuing education for the improvement of professional intervention in patient care.

Continuing education has a vital and unique role to play in enabling the practitioner to maintain professional competence. The contributions of continuing education supplement formal preparatory education and practice experience. The future for pharmacy continuing education is tied to the transition currently underway as pharmacy emphasizes involvement in patient care. The Pharm.D.'s affect on the pharmacist, acceptance of the pharmacist in a new role, preparation of pharmacists to deal with an aging population, and capitalizing on the movement toward health promotion are all challenges that face continuing pharmacy educators.

Clinical Competence↗
PubMed1979

Biological effects of magnetic fields: studies with microorganisms.

Five bacteria and one yeast were grown in magnetic fields of 50-900 gauss with frequencies of 0-0.3 HZ and square, triangular, or sine waveform. Growth of these microorganisms could be stimulated or inhibited depending upon the field strength and frequency of the pulsed magnetic field. Spore germination and mutation frequency were unaffected by the magnetic fields used in this study.

Bacillus subtilis↗
PubMed1979

The molecular taxonomy of Yersinia enterocolitica.

The stretches of Yersinia enterocolitica strain Ye 62 DNA which show base sequence homology with Escherichia coli strain B DNA were removed from a preparation of tritiated Y. enterocolitica DNA by DNA reassociation techniques. This DNA preparation was then used in reassociation reactions with DNA from various selected strains of Yersinia and coliform bacteria. The results suggest that the bulk of the genes, which are in common between Y. enterocolitica and E. coli, are different from those shared by Y. enterocolitica and other species of Yersinia.

Base Sequence↗