A numerical identification syterm for airways in the lung

Jd, Mortensen; Young, Johanne D.; Stout, L. Clarke; Stout, Alison; Bagley, Barry; Schaap, Robert N.

doi:10.1002/ar.1092060112

Cited by 15 publications

(8 citation statements)

References 11 publications

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“…and small bronchi (1-3 mm o.d.). Since the branching pattern in the cat airway is not symmetrical and regular as in the case of humans (Mortensen, Young, Strout, Strout, Bagley & Schaap, 1983), but is similar to that of dog (Amis & McKiernan, 1987), the diameter of bronchi does not necessarily correlate with the order of branching of the bronchi. The diameters of segmental bronchi of lobar bronchi in each lobe were in the range of 3-5 mm i.d., and bronchioles (> 1 mm) could be easily identified by the lack of cartilage through microscopic observations.…”

Section: Methodsmentioning

confidence: 91%

Regional difference in the distribution of L‐NAME‐sensitive and ‐insensitive NANC relaxations in cat airway.

Takahashi

Tanaka

Abdullah

et al. 1995

The Journal of Physiology

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1. To investigate the distribution profile of functional inhibitory non-adrenergic noncholinergic (i-NANC) nerves and the contribution of NO to the NANC relaxation in the cat, we studied the effects of NW-nitro-L-arginine methyl ester (L-NAME) on NANC relaxation elicited by electrical field stimulation (EFS) in the trachea, bronchus and bronchiole. 2. EFS applied to the tracheal smooth muscle during contraction induced by 5-HT (10-5 M) in the presence of atropine (10-6 M) and guanethidine (10-6 M) elicited a monophasic NANC relaxation. By contrast, NANC relaxation elicited in the peripheral airway was biphasic, comprising an initial fast followed by a second slow component and L-NAME (10-5 M) selectively abolished the first component without affecting the second one. In the trachea, L-NAME (10-5 M) completely suppressed the monophasic NANC relaxation when single or short repetitive stimuli (< 5) with 1 ms pulse duration were applied. However, at higher repetitive stimuli (> 10) with 1 or 4 ms pulse duration, suppression of NANC relaxation was incomplete. 3. In the small bronchi obtained from L-NAME-pretreated cats, EFS applied during contraction induced by 5-HT (10-5 M) elicited only the slow component of NANC relaxation which is sensitive to tetrodotoxin. 4. In the peripheral airway, a newly synthesized VIP antagonist (10-6 M) or o-chymotrypsin (1 U ml-') considerably attenuated the amplitude of L-NAME -insensitive relaxation.5. Single or repetitive EFS consistently evoked excitatory junction potentials (EJPs) in the central and peripheral airways. When tissues were exposed to atropine (10-6 M) and guanethidine (10-6 M), single or repetitive EFS did not alter the resting membrane potential. 6. These results indicate that at least two neurotransmitters, possibly NO or NO-containing compounds and VIP, are involved in i-NANC neurotransmission and the distribution profile of the two components differs in the central and peripheral airway of the cat.The tracheobronchial smooth muscle is innervated by nerve fibres from cranial parasympathetic outflow and sympathetic trunks (Smith & Taylor, 1971). Recent studies revealed that the cranial parasympathetic nervous system in the airway contains non-adrenergic non-cholinergic (NANC) inhibitory nerves in addition to the well-documented cholinergic excitatory nerve fibres. Furthermore, activation of C-fibre afferent (sensory) nerves induces a number of airway responses including smooth muscle contraction, mucus secretion and plasma exudation through NANC excitatory transmitter (Barnes, 1991

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Section: Methodsmentioning

confidence: 91%

Regional difference in the distribution of L‐NAME‐sensitive and ‐insensitive NANC relaxations in cat airway.

Takahashi

Tanaka

Abdullah

et al. 1995

The Journal of Physiology

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“…Mainly bronchi were used in the present experiments; they were classified into two categories, namely segmental branches of lobar bronchi (3-5 mm outer diameter (OD)) and small bronchi (1-3 mm OD). Since the branching pattern in the cat airway is not symmetrical and regular as it is in humans [13], but rather similar to that of dog [14], the diameter of bronchi does not necessarily correlate with their branching order. The diameters of segmental bronchi or lobar bronchi in each lobe ranged 3-5 mm in inner diameter, and bronchioles (>1 mm) can be easily identified by the lack of cartilage on microscopic observation.…”

Section: Measurement Of Isometric Tension Of the Bronchimentioning

confidence: 99%

L-NAME-sensitive and -insensitive nonadrenergic noncholinergic relaxation of cat airway in vivo and in vitro

Aizawa

Tanaka²,

Sakai³

et al. 1997

Eur Respir J

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The neurotransmitters responsible for neurogenic airway relaxation are still unknown. We investigated the effects of N ω -nitro-L-arginine methylester (L-NAME) on nonadrenergic and noncholinergic (NANC) relaxation evoked by electrical stimulation of vagus nerves in vivo and in vitro in cat.To that end, we measured pulmonary resistance during vagal nerve stimulation (VS) in vivo, and isometric tension of small bronchi (1-3 mm outer diameter) during electrical field stimulation (EFS) in vitro. During infusion of 5-hydroxytryptamine (5-HT), VS transiently decreased total pulmonary resistance in the presence of atropine and propranolol, with peak relaxation at several seconds after the VS and a gradual return to baseline within 2-3 min. L-NAME abolished the initial peak relaxation and reduced the peak amplitude, but did not affect the duration of the NANC relaxation. In small bronchi obtained from control cats, EFS evoked a biphasic NANC relaxation, comprising an initial fast component followed by a second slow component, and L-NAME (10 -5 M) selectively abolished the first component without affecting the second. Whilst in the small bronchi obtained from L-NAME pretreated cats, EFS elicited only the slow component of NANC relaxation, which was insensitive to L-NAME but sensitive to tetrodotoxin.These results indicate that nonadrenergic noncholinergic relaxation induced by vagal nerve stimulation during infusion of 5-hydroxytryptamine can be classified into two components, and that at least two neurotransmitters, including nitric oxide, are involved in the relaxation. Eur Respir J 1997; 10: 314- Neurally-mediated relaxation of airway smooth muscle in various animal species, including man, is largely nonadrenergic and noncholinergic (NANC) (see, for example, [1]). Although the neurotransmitter(s) responsible for NANC relaxation in the airways have not been conclusively identified, nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) have emerged as strong candidates [2][3][4][5][6][7].In cat airway, we have shown that NANC relaxation can be classified into two components by thresholds for activation or by sensitivity to N ω -nitro-L-arginine methylester (L-NAME), and that the pattern of L-NAME-sensitive and -insensitive components differs in central and peripheral airways [6,7]. Specifically, electrical field stimulation (EFS) elicited monophasic relaxation in the trachea, confirming previous observations [5,8], but biphasic NANC relaxations, comprising an initial fast component followed by a second slow component in the bronchioles. L-NAME selectively abolished the first component of NANC relaxation without affecting the second in bronchioles, whilst, in the trachea, L-NAME completely suppressed the monophasic NANC relaxation after single or short repetitions (<5) of 1 ms pulse stimuli; however, after more stimuli (>10) of 1 or 4 ms duration, suppression of NANC relaxation was incomplete (to 40-50% of the control value) [7]. VIP antagonists partially suppressed the L-NAME-resistant NANC relaxation....

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“…Small airways were carefully excised from the lung tissue and lung parenchyma, and pulmonary vessels running along the bronchiolar branch were carefully removed under microscopic observation. Since the branching pattern of the cat airways is not symmetrical and regular as in humans (Mortensen et al, 1983) and is similar to that of dogs (Amis & McKiernan, 1987), the diameter of the bronchi does not necessarily correlate with their order of branching, as described earlier . Segments of isolated bronchioles (0.5 ± 2 mm o.d.)…”

Section: Tissue Preparationsmentioning

confidence: 89%

Multiple calcium channels regulate neurotransmitter release from vagus nerve terminals in the cat bronchiole

Fujisawa

Onoue

Abe³

et al. 1999

British J Pharmacology

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1 Twitch-like contractions and non-adrenergic non-cholinergic (NANC) relaxations evoked by electrical ®eld stimulation (EFS) of the cat bronchiole were used to examine the voltage-activated calcium channels involved in excitatory and inhibitory neurotransmission in the cat bronchiole. 2 Nifedipine (50 mM), the L-type calcium channel antagonist, did not aect the twitch-like contraction and NANC relaxations. However, low concentrations of the N-type calcium channel blocker o-conotoxin GVIA (o-CgTX GVIA) (0.1 mM) irreversibly abolished twitch-like contractions evoked by trains of EFS 410 stimuli at 20 Hz. 3 After the prolonged treatment with 0.1 mM o-CgTX GVIA, EFS evoked initial fast and later slow NANC relaxations in the presence of 5-HT (10 mM), atropine and guanethidine (1 mM each). However increased concentration of o-CgTX GVIA (1 mM) completely suppressed the slow NANC relaxation without aecting the initial fast component. 4 o-agatoxin IVA (100 nM), the P-and Q-type calcium channel inhibitor, and nimodipine (10 mM), the L-and T-type calcium channel blocker, did not aect the amplitude of the initial fast NANC relaxation in the absence or presence of o-CgTX GVIA (1 mM). 5 The contraction or relaxation induced by exogenous acetylcholine (ACh) (0.5 mM) or the nitric oxide donor, s-nitroso-N-acetyl penicillamine (SNAP) (1 mM) were not aected by o-CgTX GVIA (1 mM). 6 Taken together, these results suggest that generation of twitch-like contraction and later slow NANC relaxation are regulated by N-type calcium channels, whereas generation of the initial fast NANC relaxation possibly involves R-type calcium channel.

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A numerical identification syterm for airways in the lung

Cited by 15 publications

References 11 publications

Regional difference in the distribution of L‐NAME‐sensitive and ‐insensitive NANC relaxations in cat airway.

Regional difference in the distribution of L‐NAME‐sensitive and ‐insensitive NANC relaxations in cat airway.

L-NAME-sensitive and -insensitive nonadrenergic noncholinergic relaxation of cat airway in vivo and in vitro

Multiple calcium channels regulate neurotransmitter release from vagus nerve terminals in the cat bronchiole

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