Nitric oxide enhances contractile response of guinea-pig vas deferens to electrical field stimulation

1. The contractile response to histamine, acetylcholine (ACh), KCl or electrical field stimulation (EFS) was examined in paired tracheal rings (one of each being denuded by mucosal rubbing), which were mounted in muscle chambers filled with a continuously aerated physiological salt solution at 37°C. 2. Removal of the respiratory mucosa increased the sensitivity of airway muscle to ACh, histamine and EFS, but not to KCl. The hypersensitivity of denuded rings to histamine and EFS was greater than to ACh. Atropine reduced the histamine hypersensitivity observed. 3. Pretreating intact preparations with indomethacin augmented their responsiveness to EFS, histamine and ACh. 4. Indomethacin augmentation of histamine- and EFS-induced responses was greater in preparations without epithelium. 5. We conclude that the airway mucosa may be associated with a factor that reduces airway smooth muscle responsiveness to stimulation.

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Adenosine and dipyridamole: actions and interactions on the contractile response of guinea-pig ileum to high frequency electrical field stimulation

British Journal of Pharmacology ◽

10.1111/j.1476-5381.1985.tb16159.x ◽

1985 ◽

Vol 84 (3) ◽

pp. 765-771 ◽

Cited By ~ 12

Author(s):

E. Hayashi ◽

T. Maeda ◽

K. Shinozuka

Keyword(s):

Guinea Pig ◽

High Frequency ◽

Contractile Response ◽

Electrical Field Stimulation ◽

Field Stimulation ◽

Guinea Pig Ileum ◽

Electrical Field

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Cholinergic and nonadrenergic mechanisms in human and guinea pig airways

Journal of Applied Physiology ◽

10.1152/jappl.1984.56.4.958 ◽

1984 ◽

Vol 56 (4) ◽

pp. 958-965 ◽

Cited By ~ 49

Author(s):

S. M. Taylor ◽

P. D. Pare ◽

R. R. Schellenberg

Keyword(s):

Guinea Pig ◽

Contractile Response ◽

Electrical Field Stimulation ◽

Field Stimulation ◽

Inhibitory Pathway ◽

Electrical Field ◽

Methods Of Analysis ◽

Human Airways ◽

Human Bronchi

Electrical field stimulation (70 V, 1 ms, 0.2–500 Hz) of human bronchial strips and guinea pig tracheal chains produced contractile and relaxant responses. Contractions were blocked by atropine, 10(-6) M, and tetrodotoxin (TTX), 0.1–1.0 micrograms/ml, demonstrating a cholinergic excitatory neural component. Frequencies causing half-maximal contractile response to field stimulation (EFc 50) were 10 +/- 2 Hz for guinea pig and 13 +/- 1 Hz for human airways. Relaxations were unmasked by atropine 10(-6) M and slightly diminished by propranolol in guinea pig but not human airways, demonstrating a predominantly nonadrenergic inhibitory pathway in both species. Relaxation of intrinsic tone occurred at stimulation frequencies of 1 Hz or more. Frequencies causing half-maximal relaxation (EFi 50) were 3.5 +/- 0.3 Hz for guinea pig trachealis and 38 +/- 6 Hz for human bronchi. Following 1 microgram/ml TTX, EFi 50 values increased to 104 +/- 12 and 70 +/- 14 Hz, respectively. Frequencies of field stimulation that were inhibitable by TTX (less than or equal to 20 Hz) induced greater relaxation in guinea pig than human airways (70 vs. 10% of the maximal relaxation to 10(-2) M theophylline, respectively). The methods of analysis outlined in this study can be used to compare relative degrees of functional innervation between tissues from the same or different species.

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Influence of Endothelial Nitric Oxide on Adrenergic Contractile Responses of Human Cerebral Arteries

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199607000-00012 ◽

1996 ◽

Vol 16 (4) ◽

pp. 623-628 ◽

Cited By ~ 17

Author(s):

Martín Aldasoro ◽

Carmen Martínez ◽

José M. Vila ◽

Pascual Medina ◽

Salvador Lluch

Keyword(s):

Nitric Oxide ◽

Contractile Response ◽

Cerebral Arteries ◽

Electrical Field Stimulation ◽

Field Stimulation ◽

Oxide Formation ◽

Electrical Field ◽

Contractile Responses ◽

Nitric Oxide Formation ◽

Endothelial Nitric Oxide

The present study was designed to investigate the influence of the endothelium and that of the L-arginine pathway on the contractile responses of isolated human cerebral arteries to electrical field stimulation (EFS) and norepinephrine. Rings of human middle cerebral artery were obtained during autopsy of 19 patients who had died 3–8 h before. EFS (1–8 Hz) induced frequency-dependent contractions that were abolished by tetrodotoxin, prazosin, and guanethidine (all at 10-6 M). The increases in tension were of greater magnitude in arteries denuded of endothelium. NG-monomethyl L-arginine (L-NMMA 10-4 M) potentiated the contractile response to EFS in artery rings with endothelium but did not influence responses of endothelium-denuded arteries. L-arginine (10-4 M) reversed the potentiating effects of L-NMMA on EFS-induced contractions. Norepinephrine induced concentration-dependent contractions, which were similar in arteries with and without endothelium or in arteries treated with L-NMMA. Indomethacin (3 × 10−6 M) had no significant effect on the contractile response to EFS or on the inhibition by L-NMMA of acetylcholine-induced relaxation. These results suggest that the contractile response of human cerebral arteries to EFS is modulated by nitric oxide mainly derived from endothelial cells; although adrenergic nerves appear to be responsible for the contraction, the transmitter involved in the release of nitric oxide does not appear to be norepinephrine. The effects of L-NMMA in this preparation appear to be due to inhibition of nitric oxide formation rather than caused by cyclooxygenase activation.

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