Antagonism by Some β-Adrenoceptor-Blocking Agents to Cholinergic Stimulation of Skeletal Muscle in vitro

Pharmacology ◽  
1979 ◽  
Vol 18 (6) ◽  
pp. 319-326
Author(s):  
V.V. Kelkar ◽  
R.S. Gupta† ◽  
N.U. Jariwala ◽  
N.J. Joshi
Keyword(s):  
Skeletal Muscle ◽  
Cholinergic Stimulation ◽  
Beta Adrenoceptor ◽  
Blocking Agents ◽  
Stimulation Of

Comparative Physiology of the Vertebrate Autonomic Nervous System

1963 ◽  
Vol 40 (3) ◽  
pp. 421-436
Author(s):  
G. BURNSTOCK ◽  
G. CAMPBELL
Keyword(s):  
Nerve Stimulation ◽  
Histological Study ◽  
Circular Muscle ◽  
Vascular Supply ◽  
Evolutionary Significance ◽  
Blocking Agents ◽  
Pelvic Nerves ◽  
Drug Actions ◽  
Stimulation Of

1. A histological study of the structure of the urinary bladder of the ringtail possum has been made. The innervation of the bladder has been studied in vitro, using the technique of analytical pharmacology. 2. The bladder has well-defined inner longitudinal and outer circular muscle layers. Nerves supplying the bladder are found both in the pelvic nerves and in the vesical nerves which run with the vascular supply of the bladder fundus. Ganglia have been demonstrated along the trunks of the vesical nerves and also aggregated at the bladder neck. 3. The response of the bladder to stimulation of either nerve supply in situ or in vitro is always a simultaneous contraction of both longitudinal and circular muscles. Inhibitory responses to nerve stimulation have never been observed. The optimal frequency for stimulation of these nerves at 30° C. is 50 pulses/sec. 4. The bladder is contracted by ACh and 5-hydroxytryptamine, but is relaxed by adrenaline, noradrenaline and histamine. 5. The response to nerve stimulation is reduced by atropine and potentiated by eserine. Adrenergic blocking agents do not affect the nerve-mediated response unless they also affect the response to applied ACh in a similar manner. 6. Ganglionic blocking agents, in concentrations which do not reduce the response to ACh, cause up to a 40% reduction of the response to stimulation of either the vesical or the pelvic nerves. 7. It is concluded that the nerve fibres supplying the possum bladder are cholinergic, perhaps 40 % of them being stimulated pre-ganglionically. 8. The evolutionary significance of these observations is discussed. 9. Some points of pharmacological interest have been discussed in relation to drug actions on placental mammal preparations.

scholarly journals Electrical Pulse Stimulation of Cultured Human Skeletal Muscle Cells as an In Vitro Model of Exercise

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33203 ◽  
Author(s):  
Nataša Nikolić ◽  
Siril Skaret Bakke ◽  
Eili Tranheim Kase ◽  
Ida Rudberg ◽  
Ingeborg Flo Halle ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
In Vitro Model ◽  
Muscle Cells ◽  
Electrical Pulse Stimulation ◽  
Human Skeletal Muscle Cells ◽  
Vitro Model ◽  
Pulse Stimulation ◽  
Stimulation Of

Chymodenin, a duodenal peptide: specific stimulation of chymotrypsinogen secretion

1975 ◽  
Vol 229 (6) ◽  
pp. 1680-1686 ◽  
Author(s):  
JW Adelson ◽  
SS Rothman
Keyword(s):  
Protein Synthesis ◽  
Protein Secretion ◽  
Digestive Enzymes ◽  
Specific Response ◽  
Zymogen Granule ◽  
Cholinergic Stimulation ◽  
Isolated Pancreas ◽  
Specific Stimulation ◽  
Stimulation Of

Chymodenin, a basic porcine duodenal peptide, was administered to anesthetized rabbits intravenously or added to the medium bathing the isolated pancreas. In the 10(-8)M range, chymodenin rapidly increased chymotrypsinogen (ChTg) secretion, did not increase lipase secretion, and modestly enhanced protein secretion (which could be attributed primarily to augmented ChTg secretion). The increased ChTg output was too rapid to be the result of increased rates of protein synthesis and could not be attributed to the exocytosis os zymogen granule contents because of the enzyme-;pecific nature of the response. In contrast to shymodenin, cholinergic stimulation in vitro produced a relatively lipase-rich, chymotrypsinogen-poor secretion. Lipase and ChTg outputs, which varied relatively independently under unstimulated conditions, covaried in the presence of chymodenin. The existence of a duodenal peptide that produces an enzyme-specific response supports the hypothesis that the secretion of digestive enzymes during digestion is a highly regulated process in which the enzyme content of pancreatic secretion varies with differences in the composition of intestinal substrates.

scholarly journals Activation of protein kinase B β and γ isoforms by insulin in vivo and by 3-phosphoinositide-dependent protein kinase-1 in vitro: comparison with protein kinase B α

1998 ◽  
Vol 331 (1) ◽  
pp. 299-308 ◽  
Author(s):  
Kay S. WALKER ◽  
Maria DEAK ◽  
Andrew PATERSON ◽  
Kevin HUDSON ◽  
Philip COHEN ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Protein Kinase B ◽  
Rat Hepatocytes ◽  
Dependent Protein Kinase ◽  
L6 Myotubes ◽  
Dependent Protein ◽  
Stimulation Of

The regulatory and catalytic properties of the three mammalian isoforms of protein kinase B (PKB) have been compared. All three isoforms (PKBα, PKBβ and PKBγ) were phosphorylated at similar rates and activated to similar extents by 3-phosphoinositide-dependent protein kinase-1 (PDK1). Phosphorylation and activation of each enzyme required the presence of PtdIns(3,4,5)P3 or PtdIns(3,4)P2, as well as PDK1. The activation of PKBβ and PKBγ by PDK1 was accompanied by the phosphorylation of the residues equivalent to Thr308 in PKBα, namely Thr309 (PKBβ) and Thr305 (PKBγ). PKBγ which had been activated by PDK1 possessed a substrate specificity identical with that of PKBα and PKBβ towards a range of peptides. The activation of PKBγ and its phosphorylation at Thr305 was triggered by insulin-like growth factor-1 in 293 cells. Stimulation of rat adipocytes or rat hepatocytes with insulin induced the activation of PKBα and PKBβ with similar kinetics. After stimulation of adipocytes, the activity of PKBβ was twice that of PKBα, but in hepatocytes PKBα activity was four-fold higher than PKBβ. Insulin induced the activation of PKBα in rat skeletal muscle in vivo, with little activation of PKBβ. Insulin did not induce PKBγ activity in adipocytes, hepatocytes or skeletal muscle, but PKBγ was the major isoform activated by insulin in rat L6 myotubes (a skeletal-muscle cell line).

scholarly journals When phosphorylated at Thr148, the β2-subunit of AMP-activated kinase does not associate with glycogen in skeletal muscle

2016 ◽  
Vol 311 (1) ◽  
pp. C35-C42 ◽  
Author(s):  
Hongyang Xu ◽  
Noni T. Frankenberg ◽  
Graham D. Lamb ◽  
Paul R. Gooley ◽  
David I. Stapleton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Carbohydrate Binding ◽  
Binding Function ◽  
Physiological Relevance ◽  
Amp Activated Protein Kinase ◽  
Fast Twitch ◽  
Stimulation Of

The 5′-AMP-activated protein kinase (AMPK), a heterotrimeric complex that functions as an intracellular fuel sensor that affects metabolism, is activated in skeletal muscle in response to exercise and utilization of stored energy. The diffusibility properties of α- and β-AMPK were examined in isolated skeletal muscle fiber segments dissected from rat fast-twitch extensor digitorum longus and oxidative soleus muscles from which the surface membranes were removed by mechanical dissection. After the muscle segments were washed for 1 and 10 min, ∼60% and 75%, respectively, of the total AMPK pools were found in the diffusible fraction. After in vitro stimulation of the muscle, which resulted in an ∼80% decline in maximal force, 20% of the diffusible pool became bound in the fiber. This bound pool was not associated with glycogen, as determined by addition of a wash step containing amylase. Stimulation of extensor digitorum longus muscles resulted in 28% glycogen utilization and a 40% increase in phosphorylation of the downstream AMPK target acetyl carboxylase-CoA. This, however, had no effect on the proportion of total β2-AMPK that was phosphorylated in whole muscle homogenates measured by immunoprecipitation. These findings suggest that, in rat skeletal muscle, β2-AMPK is not associated with glycogen and that activation of AMPK by muscle contraction does not dephosphorylate β2-AMPK. These findings question the physiological relevance of the carbohydrate-binding function of β2-AMPK in skeletal muscle.

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