Search PubMed⌕ Search

Biomedical subjects

E Gutmann

Publications and source records attributed to E Gutmann.

At least 37 records · Page 2Linked to original sources
PubMed1976

Testosterone-induced changes of choline acetyl-transferase and cholinesterase activities in rat levator ani muscle.

One year after castration the activities of choline acetyltransferase (ChAc) and of cholinesterase (ChE) in the levator ani (LA) muscle of male rats were lowered by 42 and 79% respectively. The weight of the muscle corresponded to 15% of control values. These changes were not accompanied by a decrease in the number of the muscle fibres. Treatment with testosterone rapidly increased the activity of ChAc and the weight of the muscle near to control values; the restoration of ChE was less complete. Testosterone produced an increase in the size of the muscle fibres and increased the histochemically observed activity of ChE in the postsynaptic part of the motor end-plates. In non-castrated rats the administration of testosterone increased the weight ofthe LA muscle, but was not accompanied by an increase of ChAc above control values.

Acetyltransferases↗
PubMed1976

Effects of castration, testosterone and immobilization on the activities of choline acetyltransferase and cholinesterase in rat limb muscles.

Thirteen months after castration of male rats the weight of their soleus muscles was lowered to 82% and their choline acetyltransferase (ChAc) activity to 83% of control values. The administration of testosterone lasting 5 weeks increased the weight of the soleus muscles of castrated animals by 19% and their ChAc activity bu 37%. Changes in the activity of cholinesterase occurring after castration and testosterone treatment were not statistically significant. It is assumed taht the effect of testosterone on the activity of ChAc was mainly due to an increase in the functional activity of the motoneurones innervating the muscle. Rapid developmental increase of ChAc activity was observed in the muscles of intact rats between the age of 48 and 82 days. During this period of development the activity of ChAc rose faster than the weight of the muscles. Testosterone had no effect on the weight and ChAc activity of the soleus and extensor digitorum longus muscles of non-castrated rats after 1 week's administration; after 5 weeks' administration the weight of the muscles and their ChAc activity were diminished. After the soleus muscles of non-castrated rats had been immobilized for 10 days, their ChAc activity was 56% and their weight 51% of control values. The administration of testosterone did not alter the effect of immobilization on the ChAc and weight of the muscle.

Acetyltransferases↗
PubMed1976

Passive immunological enhancement of muscle allografts in rats.

The effect of the passive administration of antiserum obtained from recipients immunized with antigens from H-1 + non-H-1 incompatible donors on muscle allograft survival in rats was studied. In transplantation across the non-H-1 antigenic barrier (H-1 compatible but non-H-1 incompatible) a satisfactory degree of immunological enhancement was achieved. Recovery of contractile properties of muscle allografts after different immunological treatments of the recipients was compared.

Animals↗
PubMed1976

Neurotrophic relations.

Increasing evidence for the existence of neurotrophic (non-impulse) mechanisms, especially in nerve-muscle cell relations, has been discussed. Studies on axoplasmic transport, release of agents (other than transmitter) from the nerve, and possible transfer of macromolecules at the NMJ and on differentiation of impulse and non-impulse (neurotrophic) activities have advanced, but not solved, the basic questions. Progress has been slowed because often less than adequate indicators of neurotrophic functions have been used and because only a single neurotrophic agent was generally assumed. Neurotrophic actions are best understood as components of multiple regulation in the context of general intercellular relations. The analysis of neurotrophic regulations will become clear only after chemical definition of the neurotrophic agents. Until then, study of the differentiation and interaction of neuronal impulse and non-impulse activities is, and will remain, an important problem for an understanding of the plasticity of the NMJ and muscle.

Acetylcholine↗
PubMed1976

Fast and slow motor units in ageing.

The differences in onset and degree of old age changes in different muscles are explained by the differentiation and different reactivity of fast and slow motor units with respect to physiological, structural and biochemical characteristics. The main changes in the motor units in old age are described. The general basic change is a progressive random disturbance of neuromuscular contact ascribed to a decrease of the trophic function of the neuron. The main motor disturbances in old age, i.e; slowness, decrease of muscle strength and lack of fine coordination are explained in terms of physiological changes in senescent motor units. The reactions of senescent motor units differ from one unit to another as shown, e.g. in denervation, reinnervation and regeneration (transplantation) studies. The trend to a shift from a heterogeneous to a more uniform muscle fibre pattern and the defficiencies in recovery of the original muscle fibre pattern in reinnervation and regeneration of senescent muscle is demonstrated and explained by a decrease of the differentiating capacity of different motor units. The changes in the heterogeneous fibre pattern of skeletal and the homogeneous fibre pattern of the papillary heart muscle in old age are contrasted.

Aging↗
PubMed1976

Independence of changes in contraction properties and myofibrillar ATPase activity of denervated mammalian muscle on length of nerve stump.

1. Contractile properties of the fast extensor digitorum longus of one-month-old rats and of the fast peroneus longus muscles of adult rabbits were studied in vitro at 36 degrees C after nerve section close to the muscle. Changes in contraction properties (prolongation) are not observed until 48 hours after denervation in the rat and 14-30 days in the rabbit. 2. At no period after denervation are differences in twitch isometric contraction properties dependent on the length of the sectioned nerve stump. This lack of dependence of contractile behavior after denervation is in contrast to many metabolic changes which show a clear dependence on the length of the nerve stump. 3. It is concluded that the onset of denervation changes in contractile behavior are related to the loss of nerve-impulse activity, while the transient early metabolic changes are related to changes of fast axoplasmic flow, initiated after nerve section and therefore dependent on length of sectioned nerve stump.

Adenosine Triphosphatases↗
PubMed1975

Changes of ribosomal capacity for protein synthesis, contraction and histochemical properties of muscle after implantation of fast nerve into denervated and into self-reinnervated slow soleus muscle of the rat.

The ribosomal capacity for protein synthesis in the fast extensor digitorum longus muscle of the rat is markedly higher than in the slow soleus muscle. Implantation of the "fast" peroneal nerve into the denervated or into the self-reinnervated soleus muscle results in transformation (increase) of capacity of isolated ribosomes for protein synthesis into that of the fast muscle type. The degree of transformation is higher after implantation into the self-reinnervated than into the denervated soleus muscle. A high degree of recovery of weight and tetanic tension output is recorded after the "fast" nerve implantation. The effect of transformation with respect to contraction properties is considerably more marked in the case of heteroinnervation of the denervated muscle and persists even after 5 months of heteroinnervation. Transformation of the histochemical muscle fibre pattern is also more pronounced after heteroinnervation of the denervated than self-reinnervated soleus muscle; the muscle acquires the fibre pattern of the fast extensor digitorum longus muscle. The acquisition of the reciprocal pattern of oxidative and glycolytic enzymes suggests that the activation of protein synthesis induced by the foreign "fast" nerve supply is coupled with the operation of specific RNA species.

Animals↗
PubMed1975

A comparison between the free grafting of sliced and intact muscles in the rat-1.

Transverse slicing is a new technique whereby a mammalian muscle can be freely grafted with success. This method eliminates contamination of the early graft by surviving muscle fibres and allows one to measure the development of contractile properties on a uniform population of regenerating muscle fibres.?IOAuthor

Adenosine Triphosphatases↗
PubMed1975

Regneration in free grafts of normal and denervated muscles in the rat: morphology and histochemistry.

Intact soleus and extensor digitorum longus muscles in the rat were freely grafted to the contralateral leg after either no preliminary treatment or 14 days prior denervation. Normal muscle grafts during the first week were characterized by a central zone of degenerating original muscle fibers (disappearing by 7-9 days) and a peripheral zone, containing regenerating muscle as well as small numbers of surviving original muscle fibers. A radial gradient of regeneration was establihed, with more mature muscle at the periphery and less mature muscle toward the center. Denervated grafts were characterized by rapid degeneration (within 2-3 days) of original muscle fibers in the central area, rapid appearance of regenerating muscle fibers (e.g. cross striations by 5 days) with uniform levels of differentiation throughout the graft and larger numbers of surviving original muscle fibers at the periphery. During the first week, stages of muscle differentiation in denervated grafts were attained 1-2 days earlier than comparable stages in normal grafts. Later stages of muscle differentiation were similar in both types of grafts. Histochemical studies revealed a loss of enzyme activity (phosphorylase, ATPase and SDH) in the center of early (2-4-day) normal and denervated grafts. Denervated grafts, however, possessed a thicker peripheral rim of enzymatically active surviving muscle fibers than normal grafts. In both types of grafts the old muscle fibers in the center were replaced by enzymatically active regenerating muscle fibers which stained uniformaly (ATPase) until 30 days. By 60 days a mixed fiber pattern had developed. Muscle spindles were found within the grafts.

Adenosine Triphosphatases↗
PubMed1975

Regeneration in grafts of normal and denervated rat muscles. Contractile properties.

The soleus or extensor digitorum longus muscles of young rats were freely garfted into the bed of the corresponding contralateral muscle. The grafts were of normal muscle or muscles which had been denervated for 14 days. Grafts of normal muscle were characterized by little or no contractile activity for the first 2-4 days after transplantation. In contrast, denervated grafts contracted weakly, but consistently, throughout this early period. The patterns of contraction were complex. In early transplants, the contractions were due entirely to surviving muscle fibers in the graft, and the contractile characteristics were those of denervated muscle fibers. After the first week, contractions of newly regenerating muscle fibers within the grafts were superimposed upon and later took over those from the fibers that survived the original transplantation. The contraction times approached those of the normal soleus or extensor muscles during the second month after grafting, and the grafts contracted like fast or slow muscles.

Animals↗
PubMed1975

Contractile and histochemical properties of regenerating cross-transplanted fast and slow muscles in the rat.

The soleus (SOL) or extensor digitorum longus (EDL) muscles of month-old rats were denervated for 14 days and then cross-transplanted so that the fast muscle was placed into the bed of the slow muscle and vice versa. At 17, 30, 60, and 90 days the transplants were tested for certain contractile and histochemical properties. By 90 days the cross-transplanted SOL showed complete conversion of the full contraction time and nearly complete conversion of the half relaxation time to those of the normal EDL. In contrast, the contraction and relaxation times of the cross-transplanted EDL became considerably slowed, but did not attain the values of the normal SOL. Histochemical staining for ATPase and SDH activity demonstrated similar transformations of fiber types. The degree of transformation of twitch and histochemical characteristics in cross-transplanted muscles was greater than the values reported after cross-innervation of the same muscles. The cross-transplantation model has certain advantages over nerve cross-union experiments because the cross-transplanted muscle is placed in the normal functional environment of the other muscle.

Adenosine Triphosphatases↗