Effects of antigen on tracheal circulation and smooth muscle in sheep of different ages

The effects of Ascaris suum antigen on tracheal circulation and tracheal smooth muscle tone were compared in two groups of sheep: the first group was 1 yr old (14 sheep) and the second 5 yr old (8 sheep). Cranial tracheal arteries of anesthetized and paralyzed sheep were perfused at constant flow with monitoring of perfusion pressure. Tracheal smooth muscle tone was assessed by measuring changes in the external diameter of the cranial trachea. Close-arterial injection of antigen (1–20 micrograms) in young sheep produced dose-dependent vasodilation (6.1–15.5% fall in perfusion pressure) and smooth muscle contraction (0.06–0.28 mm reduction in tracheal diam). In old sheep, antigen (1–20 micrograms) produced vasoconstriction (4.1–16.8%) but no smooth muscle response. The smooth muscle contraction in young sheep was blocked by mepyramine (2 mg/kg iv) suggesting mediation by release of histamine. The vasodilation in young sheep and the vasoconstriction in old sheep were reduced by indomethacin (5 mg/kg iv), and the residual response was further reduced by FPL 55712 (2 mg/kg iv), suggesting mediation by both cyclooxygenase products and leukotrienes. Thus antigen given in the tracheal vasculature releases a mixture of inflammatory mediators. This mixture of mediators or their actions on the tracheal vasculature and smooth muscle may depend on the age of the sheep.

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Inhibition of prostate smooth muscle contraction by the LIM kinase inhibitor, SR-7826: A new anticontractile strategy and implications for a role of LIM kinases in the control of prostate smooth muscle tone

European Urology Supplements ◽

10.1016/s1569-9056(17)30174-4 ◽

2017 ◽

Vol 16 (3) ◽

pp. e178

Author(s):

Q. Yu ◽

C. Gratzke ◽

Y. Wang ◽

B. Rutz ◽

A. Herlemann ◽

...

Keyword(s):

Smooth Muscle ◽

Muscle Contraction ◽

Kinase Inhibitor ◽

Muscle Tone ◽

Smooth Muscle Contraction ◽

Lim Kinase ◽

Smooth Muscle Tone

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Tracheal smooth muscle responses to substance P and neurokinin A in the piglet

Journal of Applied Physiology ◽

10.1152/jappl.1992.72.3.1090 ◽

1992 ◽

Vol 72 (3) ◽

pp. 1090-1095 ◽

Cited By ~ 26

Author(s):

B. Haxhiu-Poskurica ◽

M. A. Haxhiu ◽

G. K. Kumar ◽

M. J. Miller ◽

R. J. Martin

Keyword(s):

Smooth Muscle ◽

Substance P ◽

Muscle Contraction ◽

Muscle Tension ◽

Age Groups ◽

Smooth Muscle Contraction ◽

Tracheal Smooth Muscle ◽

Neurokinin A ◽

Dose Dependent Increase ◽

Dose Dependent

The tachykinins substance P (SP) and neurokinin A (NKA) have been shown to induce airway smooth muscle contraction in mature animals, and the enzyme neutral endopeptidase (NEP) modulates this effect. We evaluated maturation of SP- and NKA-induced tracheal smooth muscle contraction and modulation of their effects by NEP in anesthetized, paralyzed, and artificially ventilated piglets less than 4 days, 2–3 wk, and 10 wk of age. Tracheal smooth muscle tension was measured in vivo from an open tracheal segment by use of a force transducer. Intravenous SP caused a dose-dependent increase in tracheal tension in all three age groups; however, the response in less than 4-day-old piglets was significantly weaker than in 2- to 3- and 10-wk-old piglets. NKA caused a dose-dependent increase in tracheal tension only in 2- to 3- and 10-wk-old piglets. The response of tracheal tension to NKA was weaker than the response to SP in all age groups. Atropine (2 mg/kg) significantly diminished the responses of tracheal tension to SP and NKA, indicating a cholinergic contribution to these responses at all ages. Intravenous thiorphan, a known NEP inhibitor, potentiated the effects of SP only in 2- to 3- and 10-wk-old piglets and did not affect the response of tracheal tension to NKA at any age. Biochemical analyses demonstrated a significant increase in tracheal NEP activity in comparably aged piglets over the first 10 wk of life.(ABSTRACT TRUNCATED AT 250 WORDS)

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Receptor mechanisms of serotonin-induced prenodal lymphatic constriction in the canine forelimb

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1998.274.2.h650 ◽

1998 ◽

Vol 274 (2) ◽

pp. H650-H654 ◽

Cited By ~ 2

Author(s):

David E. Dobbins

Keyword(s):

Smooth Muscle ◽

Muscle Contraction ◽

Muscle Activity ◽

Receptor Agonist ◽

Perfusion Pressure ◽

Smooth Muscle Contraction ◽

Constant Flow ◽

Vasoactive Agents ◽

Arterial Infusion

Numerous endogenous vasoactive agents have been shown to cause lymphatic smooth muscle contraction. In this study, we assessed the ability of serotonin (5-HT) to alter lymphatic smooth muscle activity and elucidated the receptor mechanisms of 5-HT’s actions. Both intralymphatic and intra-arterial administration of 5-HT significantly increased lymphatic smooth muscle activity in lymphatics perfused at constant flow, as indicated by an increase in lymphatic perfusion pressure. The 5-HT-induced increase in lymphatic perfusion pressure is attenuated but not blocked by the intra-arterial infusion of phentolamine, suggesting the involvement of α-adrenoreceptors and 5-HT receptors. Intralymphatic infusion of the 5-HT2-receptor-agonist α-methylserotonin significantly increased lymphatic perfusion pressure, either alone or when administered into an α-receptor blocked preparation, whereas the 5-HT1-receptor-agonist carboxyamidotryptamine maleate did not effect the prenodal lymphatics. These data indicate that the lymphatic smooth muscle contraction produced by 5-HT is mediated both by lymphatic α-adrenoreceptors and 5-HT2 receptors.

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Effect of tracheal smooth muscle tone on collapsibility of immature airways

Journal of Applied Physiology ◽

10.1152/jappl.1988.65.2.863 ◽

1988 ◽

Vol 65 (2) ◽

pp. 863-869 ◽

Cited By ~ 29

Author(s):

R. B. Penn ◽

M. R. Wolfson ◽

T. H. Shaffer

Keyword(s):

Smooth Muscle ◽

Muscle Tone ◽

Flow Characteristics ◽

Smooth Muscle Contraction ◽

Chamber Pressure ◽

Developmental Difference ◽

Pressure Flow ◽

Smooth Muscle Tone ◽

Airway Function ◽

Newborn Animals

To test the influence of smooth muscle tone on extremely immature airways, tracheal segments (n = 19) were excised from premature lambs at 114-121 days gestation and mounted in a chamber filled with Krebs solution. Inflation (Si) and collapsing (Sc) compliance were determined by altering transmural pressure from 30 to 0 Torr and -30 to 0 Torr, respectively, both during control (C) and after acetylcholine (ACh) administration (experimental, E). Flow (V = 2-15 l/min) was then introduced through the tracheal lumen while chamber pressure (Pc) was increased from 0 to 30 Torr and driving pressure (Pd) was recorded for both C and E conditions. Tracheae were found to be extremely compliant; both Si and Sc were significantly (P less than 0.005) lower after ACh administration. Resistance to airflow (R = Pd/V) was also significantly (P less than 0.05) lower after ACh administration at each compressive pressure and each flow value. These results suggest that the highly compliant preterm trachea exhibits pressure-flow characteristics similar to a Starling resistor, and the effects of compressive pressures may be attenuated by ACh-induced smooth muscle contraction. Comparison of these results with data from adult and newborn animals suggests a developmental difference in tracheal mechanics and pressure-flow relationships, as well as in the way airway function is altered by smooth muscle stimulation.

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Cold and hyperosmolar fluids in canine trachea: vascular and smooth muscle tone and albumin flux

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.3.1309 ◽

1989 ◽

Vol 66 (3) ◽

pp. 1309-1315 ◽

Cited By ~ 20

Author(s):

M. E. Deffebach ◽

R. O. Salonen ◽

S. E. Webber ◽

J. G. Widdicombe

Keyword(s):

Smooth Muscle ◽

Muscle Tone ◽

Control Period ◽

Smooth Muscle Contraction ◽

Hypertonic Solution ◽

Tracheal Lumen ◽

Smooth Muscle Tone ◽

Hypertonic Glucose ◽

Hypertonic Solutions ◽

Cervical Trachea

We have studied the effects of liquids of various osmolalities and temperatures on the tracheal vasculature, smooth muscle tone, and transepithelial albumin flux. In 10 anesthetized dogs a 10- to 13-cm length of cervical trachea was cannulated to allow instillation of fluids into its lumen. The cranial tracheal arteries were perfused at constant flow, with monitoring of the perfusion pressures (Ptr) and the external tracheal diameter (Dtr). Control fluid was Krebs-Henseleit solution (KH) with NaCl added to result in a 325-mosM solution (isotonic). Hypertonic solutions were KH with NaCl (warm hypertonic) or glucose (hypertonic glucose) added to result in a 800-mosM solution. All solutions were at 38 degrees C, with isotonic and the hypertonic NaCl solutions also given at 18 degrees C (cold isotonic and cold hypertonic). Fluorescent labeled albumin was given intravenously, and the change in fluorescence in the fluid was measured during each 15-min period. Changing from warm isotonic to cold isotonic decreased Dtr and Ptr. Changing from warm isotonic to warm hypertonic or hypertonic glucose decreased Ptr with no change in Dtr. The cold hypertonic responses were not different from cold isotonic responses. Warm hypertonic solution increased albumin flux into the tracheal lumen over a 15-min period to three times that of the control period, persisting for 15 min after replacement with warm isotonic solution. Cooling induces a vasodilation and smooth muscle contraction of the trachea, whereas hypertonic solutions result in vasodilation and, if osmolality is increased with NaCl, an increase in albumin flux into the tracheal lumen.

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