THE EFFECTS OF SARIN AND ATROPINE ON THE RESPIRATORY CENTER AND NEUROMUSCULAR JUNCTIONS OF THE RAT

1959 ◽  
Vol 37 (5) ◽  
pp. 651-660 ◽  
Author(s):  
W. C. Stewart
Keyword(s):  
Respiratory Rate ◽  
Large Dose ◽  
Gastrocnemius Muscle ◽  
Neuromuscular Junctions ◽  
Respiratory Arrest ◽  
Diaphragm Muscle ◽  
Respiratory Center ◽  
Nerve Supply ◽  
Higher Doses ◽  
Stimulation Of

Records were made of the contractions of a slip of diaphragm muscle which was isolated from the circulation of the rat, while the nerve supply was preserved. Simultaneous records were also made of the contractions of the opposite (circulated) hemidiaphragm, of respiratory rate, of the Hering-Breuer reflex, and of contractions of the gastrocnemius muscle in response to stimulation of the sciatic nerve.Low doses of sarin caused immediate respiratory arrest, purely central in origin; respiration was restored to normal at once when a large dose of atropine was given. When atropine was injected before sarin, much higher doses of sarin were required to depress the respiration, and now the respiratory paralysis took place at the neuromuscular junctions in the diaphragm, the respiratory center remaining relatively unaffected. It was concluded that respiratory paralysis by sarin could be purely central, purely peripheral, or both central and peripheral, depending on the doses of sarin and atropine employed.

THE EFFECTS OF SARIN AND ATROPINE ON THE RESPIRATORY CENTER AND NEUROMUSCULAR JUNCTIONS OF THE RAT

1959 ◽  
Vol 37 (1) ◽  
pp. 651-660 ◽  
Author(s):  
W. C. Stewart
Keyword(s):  
Respiratory Rate ◽  
Large Dose ◽  
Gastrocnemius Muscle ◽  
Neuromuscular Junctions ◽  
Respiratory Arrest ◽  
Diaphragm Muscle ◽  
Respiratory Center ◽  
Nerve Supply ◽  
Higher Doses ◽  
Stimulation Of

Records were made of the contractions of a slip of diaphragm muscle which was isolated from the circulation of the rat, while the nerve supply was preserved. Simultaneous records were also made of the contractions of the opposite (circulated) hemidiaphragm, of respiratory rate, of the Hering-Breuer reflex, and of contractions of the gastrocnemius muscle in response to stimulation of the sciatic nerve.Low doses of sarin caused immediate respiratory arrest, purely central in origin; respiration was restored to normal at once when a large dose of atropine was given. When atropine was injected before sarin, much higher doses of sarin were required to depress the respiration, and now the respiratory paralysis took place at the neuromuscular junctions in the diaphragm, the respiratory center remaining relatively unaffected. It was concluded that respiratory paralysis by sarin could be purely central, purely peripheral, or both central and peripheral, depending on the doses of sarin and atropine employed.

Proportion of muscles spindles supplied by skeletofusimotor axons (beta-axons) in peroneus brevis muscle of the cat

1975 ◽  
Vol 38 (6) ◽  
pp. 1390-1394 ◽  
Author(s):  
F. Emonet-Denand ◽  
Y. Laporte
Keyword(s):  
Neuromuscular Junctions ◽  
Muscle Fibers ◽  
Repetitive Stimulation ◽  
Motor Axon ◽  
Dynamic Sensitivity ◽  
Conduction Velocities ◽  
Peroneus Brevis ◽  
Stimulation Of

Of 32 cat peroneus brevis spindles, 23 (72%) were found to be supplied by a least 1 skeletofusimotor or beta-axon. A motor axon was identified as skeletofusimotor when repetitive stimulation of it elicited both the contraction of extrafusal muscle fibers and as acceleration of the discharge of primary ending, which persisted after selective block of the neuromuscular junctions of extrafusal muscle fibers. The block was obtained by stimulating single axons at 400-500/s for a few seconds. Of 135 axons supplying extrafusal muscle fibers, 24 (18%) were shown to be beta-axons; 22 beta-axons had conduction velocities ranging from 45 to 75 m/s. All but three beta-axons increased the dynamic sensitivity of primary endings. Beta-innervated spindles may also be supplied by dynamic gamma-axons.

Patient-ventilator interaction during acute hypercapnia: pressure-support vs. proportional-assist ventilation

1996 ◽  
Vol 81 (1) ◽  
pp. 426-436 ◽  
Author(s):  
V. M. Ranieri ◽  
R. Giuliani ◽  
L. Mascia ◽  
S. Grasso ◽  
V. Petruzzelli ◽  
...  
Keyword(s):  
Respiratory Rate ◽  
Dead Space ◽  
Pressure Support ◽  
Esophageal Pressure ◽  
Respiratory Drive ◽  
Resistive Load ◽  
Proportional Assist Ventilation ◽  
Pressure Time ◽  
Pressure Time Product ◽  
Stimulation Of

The objective of this study was to compare patient-ventilator interaction during pressure-support ventilation (PSV) and proportional-assist ventilation (PAV) in the course of increased ventilatory requirement obtained by adding a dead space in 12 patients on weaning from mechanical ventilation. With PSV, the level of unloading was provided by setting the inspiratory pressure at 20 and 10 cmH2O, whereas with PAV the level of unloading was at 80 and 40% of the elastic and resistive load. Hypercapnia increased (P < 0.001) tidal swing of esophageal pressure and pressure-time product per breath at both levels of PSV and PAV. During PSV, application of dead space increased ventilation (VE) during PSV (67 +/- 4 and 145 +/- 5% during 20 and 10 cmH2O PSV, respectively, P < 0.001). This was due to a relevant increase in respiratory rate (48 +/- 4 and 103 +/- 5% during 20 and 10 cmH2O PSV, respectively, P < 0.001), whereas the increase in tidal volume (VT) played a small role (13 +/- 1 and 21 +/- 2% during 20 and 10 cmH2O PSV, respectively, P < 0.001). With PAV, the increase in VE consequent to hypercapnia (27 +/- 3 and 64 +/- 4% during 80 and 40% PAV, respectively, P < 0.001) was related to the increase in VT (32 +/- 1 and 66 +/- 2% during 80 and 40% PAV, respectively, P < 0.001), respiratory rate remaining unchanged. The increase in pressure-time product per minute and per liter consequent to acute hypercapnia and the sense of breathlessness were significantly (P < 0.001) higher during PSV than during PAV. Our data show that, after hypercapnic stimulation of the respiratory drive, the capability to increase VE through changes in VT modulated by variations in inspiratory muscle effort is preserved only during PAV; the compensatory strategy used to increase VE during PSV requires greater muscle effort and causes more pronounced patient discomfort than during PAV.

Plasma 17-hydroxycorticosteroid levels during electrical stimulation of the amygdaloid complex in conscious monkeys

1958 ◽  
Vol 196 (1) ◽  
pp. 44-48 ◽  
Author(s):  
John W. Mason
Keyword(s):  
Electrical Stimulation ◽  
Large Dose ◽  
Rhesus Monkeys ◽  
Hypothalamic Stimulation ◽  
Amygdaloid Complex ◽  
Implanted Electrodes ◽  
Stimulation Of

Substantial plasma 17-OH-CS elevations invariably occurred during electrical stimulation of the amygdaloid complex in unanesthetized rhesus monkeys through chronically implanted electrodes. No evidence of localization of this effect within anatomical subdivisions of the amygdaloid complex was observed. Stimulation of the amygdala elicited plasma 17-OH-CS elevations (20 µg %/hr.) equal to those occurring with hypothalamic stimulation or injection of a large dose of ACTH (16 mg/kg), while no elevations were observed during putamen stimulation or under normal conditions.

scholarly journals Differential protein metabolism and regeneration in hypertrophic diaphragm and atrophic gastrocnemius muscles in hibernating Daurian ground squirrels

2019 ◽  
Author(s):  
Xia Yan ◽  
Xuli Gao ◽  
Xin Peng ◽  
Jie Zhang ◽  
Xiufeng Ma ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Muscle Regeneration ◽  
Protein Metabolism ◽  
Muscle Hypertrophy ◽  
Gastrocnemius Muscle ◽  
Fiber Type ◽  
Ground Squirrels ◽  
Diaphragm Muscle ◽  
Gastrocnemius Muscles

AbstractWhether differences in regulation of protein metabolism and regeneration are involved in the different phenotypic adaptation mechanisms of muscle hypertrophy and atrophy in hibernators? Two fast-type muscles (diaphragm and gastrocnemius) in summer active and hibernating Daurian ground squirrels were selected to detect changes in cross-sectional area (CSA), fiber type distribution, and protein expression indicative of protein synthesis metabolism (protein expression of P-Akt, P-mTORC1, P-S6K1, and P-4E-BP1), protein degradation metabolism (MuRF1, atrogin-1, calpain-1, calpain-2, calpastatin, desmin, troponin T, Beclin1, and LC3-II), and muscle regeneration (MyoD, myogenin, and myostatin). Results showed the CSA of the diaphragm muscle increased significantly by 26.1%, whereas the CSA of the gastrocnemius muscle decreased significantly by 20.4% in the hibernation group compared with the summer active group. Both muscles displayed a significant fast-to-slow fiber-type transition in hibernation. Our study further indicated that increased protein synthesis, decreased protein degradation, and increased muscle regeneration potential contributed to diaphragm muscle hypertrophy, whereas decreased protein synthesis, increased protein degradation, and decreased muscle regeneration potential contributed to gastrocnemius muscle atrophy. In conclusion, the differences in muscle regeneration and regulatory pattern of protein metabolism may contribute to the different adaptive changes observed in the diaphragm and gastrocnemius muscles of ground squirrels.

Assessment of specific muscle tension in dogs through functional electrical stimulation of the gastrocnemius muscle

2017 ◽  
Vol 113 ◽  
pp. 33-39
Author(s):  
B. Dries ◽  
B. Vanwanseele ◽  
I. Jonkers ◽  
J. Vander Sloten ◽  
E. Van der Vekens ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Gastrocnemius Muscle ◽  
Muscle Tension ◽  
Specific Muscle ◽  
Stimulation Of

EXPERIMENTS ON ATROPINE-RESISTANT VASODILATATION IN SALIVARY GLANDS

1963 ◽  
Vol 41 (2) ◽  
pp. 519-524 ◽  
Author(s):  
B. C. R. Strömblad ◽  
Peter E. Dresel
Keyword(s):  
Salivary Glands ◽  
Blocking Effect ◽  
Nerve Supply ◽  
Parotid Glands ◽  
Cholinergic Nerves ◽  
Parasympathetic Nerve ◽  
Ganglionic Transmission ◽  
Stimulation Of

Vasodilatation induced by stimulation of the parasympathetic nerve supply to the submaxillary and the parotid glands has long been known to be resistant to the blocking effect of atropine. We have found that dichloroisoproterenol does not block this vasodilatation, that d-tubocurarine blocks it by interfering with ganglionic transmission, and that a hemicholinium, HC-3, blocks it gradually under conditions in which interference with ganglionic transmission is excluded. It is concluded that the mechanism of vasodilatation includes the action of cholinergic nerves.

Properties of the laryngeal chemoreflex in neonatal piglets

1977 ◽  
Vol 233 (1) ◽  
pp. R30-R36 ◽  
Author(s):  
J. C. Lee ◽  
B. J. Stoll ◽  
S. E. Downing
Keyword(s):  
Electrical Stimulation ◽  
Respiratory Arrest ◽  
Relative Potency ◽  
Respiratory Drive ◽  
Neonatal Piglets ◽  
Laryngeal Nerves ◽  
Respiratory Inhibition ◽  
Respiratory Stimulant ◽  
Inhibitory Reflex ◽  
Stimulation Of

Cardiorespiratory reflex responses to laryngeal chemoreceptor stimulation were studied in 62 piglets of both sexes varying in age from 1 to 79 days. The distal trachea was cannulated to provide a free airway and the proximal end used to introduce fluids into the laryngeal area. Introduction of either water or milk produced apnea, bradycardia, and hypertension. Swab application of test fluids to the laryngeal epithelium produced similar responses. The reflex could be interrupted by flushing the laryngeal region with saline, by cutting the superior laryngeal nerves (SLN) or by anesthetizing the laryngeal epithelium with lidocaine. Electrical stimulation of SLN elicited identical responses. Respiratory inhibition by the reflex was enhanced following central depression with chloralose and overridden by administration of the respiratory stimulant, aminophylline. The relative potency of the laryngeal reflex was estimated to be equivalent to about 40% of the dose of chloralose which produced permanent respiratory arrest. It is concluded that in circumstances where respiratory drive is reduced the laryngeal inhibitory reflex is capable of caused persistent apnea and asphyxial death in the young piglet.

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