Central action of tachykinins on activity of expiratory pumping muscles

1990 ◽  
Vol 69 (6) ◽  
pp. 1981-1986 ◽  
Author(s):  
M. A. Haxhiu ◽  
N. S. Cherniack ◽  
E. van Lunteren
Keyword(s):  
Substance P ◽  
Muscle Activity ◽  
Transversus Abdominis ◽  
Neurokinin A ◽  
Moderate Increase ◽  
Neurokinin B ◽  
Expiratory Muscle ◽  
Ventral Medullary Surface ◽  
Expiratory Muscles ◽  
Diaphragm Activity

The central effects of tachykinins (substance P, neurokinin A, and neurokinin B) on the distribution of the motor activity to rib cage and abdominal expiratory muscles were studied in anesthetized tracheotomized spontaneously breathing dogs and cats. Intracisternal application of substance P (11 dogs) in doses of 10(-5) to 10(-4) M caused diaphragm electrical activity to change insignificantly from 19.3 +/- 1.9 to 24.8 +/- 3.2 units (P greater than 0.05), produced a moderate increase of triangularis sterni activity from 12.6 +/- 2.2 to 19.2 +/- 2.2 units (P less than 0.05), and stimulated a large increase of transversus abdominis activity from 9.4 +/- 2.7 to 28.5 +/- 2.6 units (P less than 0.01). Comparable effects were seen with similar doses of neurokinin A (8 dogs) and neurokinin B (3 dogs) administered intracisternally. Local application of substance P to the ventral medullary surface (5 dogs and 4 cats) also caused expiratory muscle activity to increase more than diaphragm activity, and in addition transversus abdominis activity increased to a larger extent than triangularis sterni activity. Furthermore, administration of the substance P antagonist [D-Pro2,D-Trp7,9]-SP to the ventral medullary surface decreased respiratory motor output, with expiratory muscles activity being attenuated to a greater extent than diaphragm activity. Application of neurotensin and N-methyl-D-asparate to the ventral surface of the medulla produced responses similar to those observed as a result of central administration of tachykinin peptides. The results suggest that 1) mammalian tachykinins are involved in the regulation of thoracic and abdominal expiratory muscle activity, 2) these muscles manifest substantial differences in their electrical responses to excitatory neuropeptides acting centrally, and 3) inputs from modulatory neurons located in this vicinity of the ventral medullary surface seem to be distributed unevenly to different expiratory premotor and/or motoneurons.

Expiratory muscle activity in the awake and sleeping human during lung inflation and hypercapnia

1992 ◽  
Vol 72 (3) ◽  
pp. 881-887 ◽  
Author(s):  
Y. Wakai ◽  
M. M. Welsh ◽  
A. M. Leevers ◽  
J. D. Road
Keyword(s):  
Lung Volume ◽  
Muscle Activity ◽  
Ventilatory Threshold ◽  
Minute Ventilation ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Lung Inflation ◽  
Expiratory Muscle ◽  
Intramuscular Electrodes

Expiratory muscle activity has been shown to occur in awake humans during lung inflation; however, whether this activity is dependent on consciousness is unclear. Therefore we measured abdominal muscle electromyograms (intramuscular electrodes) in 13 subjects studied in the supine position during wakefulness and non-rapid-eye-movement sleep. Lung inflation was produced by nasal continuous positive airway pressure (CPAP). CPAP at 10–15 cmH2O produced phasic expiratory activity in two subjects during wakefulness but produced no activity in any subject during sleep. During sleep, CPAP to 15 cmH2O increased lung volume by 1,260 +/- 215 (SE) ml, but there was no change in minute ventilation. The ventilatory threshold at which phasic abdominal muscle activity was first recorded during hypercapnia was 10.3 +/- 1.1 l/min while awake and 13.8 +/- 1 l/min while asleep (P less than 0.05). Higher lung volumes reduced the threshold for abdominal muscle recruitment during hypercapnia. We conclude that lung inflation alone over the range that we studied does not alter ventilation or produce recruitment of the abdominal muscles in sleeping humans. The internal oblique and transversus abdominis are activated at a lower ventilatory threshold during hypercapnia, and this activation is influenced by state and lung volume.

scholarly journals Redundancy in the central tachykinin systems safeguards puberty onset and fertility

2018 ◽  
Author(s):  
Silvia León ◽  
Chrysanthi Fergani ◽  
Rajae Talbi ◽  
Serap Simavli ◽  
Caroline A. Maguire ◽  
...  
Keyword(s):  
Substance P ◽  
Reproductive Success ◽  
Sex Steroids ◽  
Delayed Puberty ◽  
Neurokinin A ◽  
Neurokinin B ◽  
Female Mice ◽  
Gnrh Release ◽  
Lh Release ◽  
Puberty Onset

ABSTRACTThe tachykinin neurokinin B (NKB, Tac2) is critical for GnRH release. NKB signaling deficiency leads to infertility in humans. However, some patients reverse this hypogonadism resembling the fertile phenotype of Tac2KO and Tacr3KO (encoding NKB receptor, NK3R) mice despite the absence of NKB signaling. Here, we demonstrate that in the absence of NKB signaling, other tachykinins (substance P and neurokinin A [NKA], encoded by Tac1) may take over to preserve fertility. The complete absence of tachykinins in Tac1/Tac2KO mice leads to delayed puberty onset in both sexes and infertility in 80% of females (but not males), in contrast to the 100% fertile phenotype of Tac1KO and Tac2KO mice separately. Furthermore, we demonstrate that NKA controls puberty onset and LH release through NKB-independent mechanisms in the presence of sex steroids and NKB-dependent mechanisms in their absence. In summary, tachykinins interact in a coordinated manner to ensure reproductive success in female mice.

scholarly journals Respiratory Muscle Effort during Expiration in Successful and Failed Weaning from Mechanical Ventilation

2018 ◽  
Vol 129 (3) ◽  
pp. 490-501 ◽  
Author(s):  
Jonne Doorduin ◽  
Lisanne H. Roesthuis ◽  
Diana Jansen ◽  
Johannes G. van der Hoeven ◽  
Hieronymus W. H. van Hees ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Electrical Activity ◽  
Muscle Activity ◽  
Respiratory Muscle ◽  
Weaning From Mechanical Ventilation ◽  
Expiratory Muscle ◽  
Diaphragm Electrical Activity ◽  
Gastric Pressure ◽  
Weaning Failure ◽  
Expiratory Muscles

Abstract What We Already Know about This Topic What This Article Tells Us That Is New Background Respiratory muscle weakness in critically ill patients is associated with difficulty in weaning from mechanical ventilation. Previous studies have mainly focused on inspiratory muscle activity during weaning; expiratory muscle activity is less well understood. The current study describes expiratory muscle activity during weaning, including tonic diaphragm activity. The authors hypothesized that expiratory muscle effort is greater in patients who fail to wean compared to those who wean successfully. Methods Twenty adult patients receiving mechanical ventilation (more than 72 h) performed a spontaneous breathing trial. Tidal volume, transdiaphragmatic pressure, diaphragm electrical activity, and diaphragm neuromechanical efficiency were calculated on a breath-by-breath basis. Inspiratory (and expiratory) muscle efforts were calculated as the inspiratory esophageal (and expiratory gastric) pressure–time products, respectively. Results Nine patients failed weaning. The contribution of the expiratory muscles to total respiratory muscle effort increased in the “failure” group from 13 ± 9% at onset to 24 ± 10% at the end of the breathing trial (P = 0.047); there was no increase in the “success” group. Diaphragm electrical activity (expressed as the percentage of inspiratory peak) was low at end expiration (failure, 3 ± 2%; success, 4 ± 6%) and equal between groups during the entire expiratory phase (P = 0.407). Diaphragm neuromechanical efficiency was lower in the failure versus success groups (0.38 ± 0.16 vs. 0.71 ± 0.36 cm H2O/μV; P = 0.054). Conclusions Weaning failure (vs. success) is associated with increased effort of the expiratory muscles and impaired neuromechanical efficiency of the diaphragm but no difference in tonic activity of the diaphragm.

NK1 receptors mediate tachykinin-induced increase in microvascular clearance in hamster cheek pouch

1993 ◽  
Vol 265 (2) ◽  
pp. H593-H598
Author(s):  
X. P. Gao ◽  
R. A. Robbins ◽  
R. M. Snider ◽  
J. Lowe ◽  
S. I. Rennard ◽  
...  
Keyword(s):  
Substance P ◽  
Fluorescein Isothiocyanate ◽  
Cheek Pouch ◽  
Neurokinin A ◽  
Plasma Extravasation ◽  
Hamster Cheek Pouch ◽  
Neurokinin B ◽  
Dextran 70 ◽  
Fluorescein Isothiocyanate Dextran ◽  
Neurogenic Plasma Extravasation

The purpose of this study was to determine the receptor subtype(s) that mediates tachykinin-induced neurogenic plasma extravasation in the hamster cheek pouch. Changes in microvascular clearance were quantified by counting the number of leaky sites and calculating the clearance of fluorescein isothiocyanate-dextran [mol wt 70,000 (Dextran 70)] during suffusion of the cheek pouch with substance P, neurokinin A, neurokinin B, and capsaicin. Suffusion of substance P, capsaicin, and neurokinin A, but not neurokinin B, was associated with a significant concentration-dependent increase in leaky site formation and clearance of fluorescein isothiocyanate-Dextran 70 (P < 0.05). However, the responses to substance P and capsaicin were significantly greater than those to neurokinin A. Pretreatment with the selective, nonpeptide NK1 receptor antagonist, CP-96,345, significantly attenuated substance P- and capsaicin-induced but not neurokinin A-induced responses (P < 0.05). These effects were specific, since the 2R,3R enantiomer, CP-96,344, was inactive, and CP-96,345 had no significant effect on adenosine-induced responses. We conclude that, in the hamster cheek pouch, NK1 receptors are the predominant receptors that mediate neurogenic plasma extravasation.

Neurokinin A but not neurokinin B and substance P induces codeine-resistant coughs in awake guinea-pig

1992 ◽  
Vol 37 ◽  
pp. S154
Author(s):  
K. Takahama ◽  
J. Fuchikami ◽  
Y. Isohama ◽  
H. Kai ◽  
T. Miyata
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Neurokinin A ◽  
Neurokinin B

Electrical activation of expiratory muscles increases with time in pentobarbital-anesthetized dogs

1992 ◽  
Vol 72 (6) ◽  
pp. 2285-2291 ◽  
Author(s):  
D. O. Warner ◽  
M. J. Joyner ◽  
K. Rehder
Keyword(s):  
Electrical Activity ◽  
Important Variable ◽  
Transversus Abdominis ◽  
Implanted Electrodes ◽  
Expiratory Muscle ◽  
Inspiratory Muscles ◽  
Anesthetized Dogs ◽  
Expiratory Muscles ◽  
Muscle Groups ◽  
Over Time

Although the pentobarbital-anesthetized dog is often used as a model in studies of respiratory muscle activity during spontaneous breathing, there is no information regarding the stability of the pattern of breathing of this model over time. The electromyograms of several inspiratory and expiratory muscle groups were measured in six dogs over a 4-h period by use of chronically implanted electrodes. Anesthesia was induced with pentobarbital sodium (25 mg/kg iv), with supplemental doses to maintain constant plasma pentobarbital concentrations. Phasic electrical activity increased over time in the triangularis sterni, transversus abdominis, and external oblique muscles (expiratory muscles). The electrical activity of the costal diaphragm, crural diaphragm, and parasternal intercostal muscles (inspiratory muscles) was unchanged. These changes in electrical activity occurred despite stable plasma levels of pentobarbital and arterial PCO2. They were associated with changes in chest wall motion and an increased tidal volume with unchanged breathing frequency. We conclude that expiratory muscle groups are selectively activated with time in pentobarbital-anesthetized dogs lying supine. Therefore the duration of anesthesia is an important variable in studies using this model.

Expression and cellular localization of substance P/neurokinin A and neurokinin B mRNAs in the rat retina

1989 ◽  
Vol 3 (6) ◽  
pp. 527-535 ◽  
Author(s):  
Nicholas C. Brecha ◽  
Catia Sternini ◽  
Karl Anderson ◽  
James E. Krause
Keyword(s):  
Substance P ◽  
Ganglion Cell ◽  
Cellular Localization ◽  
Amacrine Cells ◽  
Specific Cell ◽  
Neurokinin A ◽  
Neurokinin B ◽  
Rat Retina ◽  
Rna Probes

AbstractThe mammalian tachykinin peptides, substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) are encoded by distinct mRNAs derived from separate preprotachykinin (PPT) genes. The SP/NKA-encoding PPT gene generates three mRNAs by alternative RNA processing: α-PPT mRNA, which encodes SP only, and β- and γ-PPT mRNAs, which encode both SP and NKA. The NKB-encoding PPT gene generates mRNAs that produce NKB. The distribution and cellular localization of SP, NKA and NKB mRNAs in the rat retina were studied by RNA blot and in situ hybridization techniques. Blot hybridization analysis of retinal RNA extracts with [32P]-labeled RNA probes complementary to SP/NKA and NKB mRNAs demonstrated single bands of hybridization at 1300 and 900 bases, respectively. Solution hybridization-nuclease protection experiments showed multiple SP/NKA-encoding transcripts with relative levels of ρ-PPT mRNA > β-PPT mRNA ≫ α-PPT mRNA. In situ hybridization histochemistry with [35S]-labeled antisense RNAs demonstrated thatSP/NKA-encoding transcripts are expressed in small-to-medium somata located in the proximal inner nuclear, inner plexiform, and ganglion cell layers, whereas NKB-encoding transcripts are expressed in small-to-medium somata located only in the ganglion cell layer. In this layer, cells containing NKB mRNAs are more numerous than those containing SP/NKA mRNAs. Only background labeling was observed in sections incubated with sense RNA probes, pretreated with RNase A prior to hybridization or incubated in hybridization buffer without the labeled probe. Immunohistochemical studies with a monoclonal antibody directed to the conserved COOH-terminal sequence of the tachykinin peptides revealed tachykinin-like immunoreactive somata with similar size and distribution to those containing SP/NKA- and NKB-encoding transcripts. These results indicate that both SP/NKA and NKB mRNAs are present in the rat retina and that the PPT genes are differentially expressed in specific cell populations. The size and distribution of these cells suggest that they are amacrine and displaced amacrine cells, however, the possibility that tachykinins are present also in ganglion cells in the rat retina cannot be ruled out.

Cerebellar role in the load-compensating response of expiratory muscle

1994 ◽  
Vol 77 (3) ◽  
pp. 1232-1238 ◽  
Author(s):  
F. Xu ◽  
D. T. Frazier
Keyword(s):  
Spinal Column ◽  
Transversus Abdominis ◽  
Vagal Afferents ◽  
Electromyographic Activity ◽  
Tracheal Occlusion ◽  
Expiratory Muscle ◽  
Expiratory Muscles ◽  
Lung Airways ◽  
Dorsal Spinal

The hypothesis that the cerebellum is involved in the load-compensating response of expiratory muscles to expiratory tracheal occlusion was tested in anesthetized cats. A continuous expiratory threshold load (ETL; 5 cmH2O) was applied to elicit consistent phasic baseline electromyographic activity in the transversus abdominis muscle (EMGab). Tracheal occlusion for single expirations (TOE) were applied, and the evoked responses were compared in the intact and decerebellate preparation. Cold blockade of the dorsal spinal column (C5-7) and bilateral vagal inactivation (cold blockade or transection) were employed to determine the role of afferents from the lung, airways, chest wall, and diaphragm in shaping the cerebellar involvement in the motor response. The results showed that 1) decerebellation increased the baseline amplitude of the integrated EMGab (fEMGab) activity (P < 0.05) with little change in expiratory duration, 2) TOE applied after decerebellation markedly increased the expiratory duration compared with the intact values (P < 0.05), with little effect on the peak fEMGab, 3) cooling the dorsal spinal columns (C5-7) did not significantly affect EMGab responses in the intact or decerebellate preparations, and 4) vagal inactivation in the intact or decerebellate preparation significantly eliminated the fEMGab responses to ETL and TOE. We conclude that the cerebellum is involved in the modulation of transversus abdominis activity during ETL and TOE. Vagal afferents provide the major sensory input for the cerebellar modulation of the expiratory loading response.

Inhomogeneous response of expiratory muscle activity to cold block of the ventral medullary surface

1991 ◽  
Vol 71 (5) ◽  
pp. 1723-1728 ◽  
Author(s):  
T. Chonan ◽  
S. Okabe ◽  
W. Hida ◽  
T. Izumiyama ◽  
Y. Kikuchi ◽  
...  
Keyword(s):  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Temperature Dependent ◽  
Rib Cage ◽  
Inspiratory Activity ◽  
Ventral Medullary Surface ◽  
Expiratory Muscles ◽  
External Oblique ◽  
Intermediate Part ◽  
Internal Oblique

We assessed the effects of cooling the ventral medullary surface (VMS) on the activity of chest wall and abdominal expiratory muscles in eight anesthetized artificially ventilated dogs after vagotomy and denervation of the carotid sinus nerves. Electromyograms (EMGs) of the triangularis sterni, internal intercostal, abdominal external oblique, abdominal internal oblique, and transversus abdominis muscles were measured with EMG of the diaphragm as an index of inspiratory activity. Bilateral localized cooling (2 x 2 mm) in the thermosensitive intermediate part of the VMS produced temperature-dependent reduction in the EMG of diaphragm and abdominal muscles. The rib cage expiratory EMGs were little affected at 25 degrees C; their amplitudes decreased at lower VMS temperatures (less than 20 degrees C) but by significantly fewer degrees than the diaphragmatic and abdominal expiratory EMGs at a constant VMS temperature. With moderate to severe cooling (less than 20 degrees C) diaphragmatic EMG disappeared, but rib cage expiratory EMGs became tonic and resumed a phasic pattern shortly before the recovery of diaphragmatic EMG during rewarming of the VMS. These results indicate that the effects of cooling the VMS differ between the activity of rib cage and abdominal expiratory muscles. This variability may be due to inhomogeneous inputs from the VMS to expiratory motoneurons or to a different responsiveness of various expiratory motoneurons to the same input either from the VMS or the inspiratory neurons.

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