scholarly journals Altered responsiveness of the guinea-pig isolated ileum to smooth muscle stimulants and to electrical stimulation after in situ ischemia

2006 ◽  
Vol 147 (4) ◽  
pp. 371-378 ◽  
Author(s):  
Rodolfo Rodriguez ◽  
Rosa Ventura-Martinez ◽  
Jacinto Santiago-Mejia ◽  
Maria R Avila-Costa ◽  
Teresa I Fortoul
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Guinea Pig

Physiological and pharmacological response of canine bronchial smooth muscle in situ

1983 ◽  
Vol 54 (1) ◽  
pp. 215-224 ◽  
Author(s):  
S. G. Hendrix ◽  
N. M. Munoz ◽  
A. R. Leff
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Maximal Response ◽  
Repeated Injection ◽  
Third Order ◽  
Bronchial Smooth Muscle ◽  
Pure Nitrogen ◽  
Parasympathetic Ganglion ◽  
The Right

We studied the isometric response of bronchial smooth muscle in a single third-order bronchus of 24 dogs in situ. Length-tension studies were performed in six dogs by repeated injection of 10(-5) mol acetylcholine (ACh) into the right bronchoesophageal artery, and the resting tension (30.6 +/- 6.9 g/cm) and length (0.76 +/- 0.14 cm) permitting maximal contraction were determined. In eight other dogs, dose-related bronchial contraction was obtained with 10(-10) to 10(-5) mol intra-arterial (ia) ACh. Supramaximal electrical stimulation of the right cervical vagus nerve and bronchial parasympathetic ganglion stimulation with ia 1–1-dimethyl-4-phenylpiperazinium (DMPP) also caused bronchial contraction. The maximal response to ia ACh (28.5 +/- 1.7 g/cm), supramaximal electrical stimulation (15.2 +/- 1.1 g/cm), and ia DMPP (10.5 +/- 3.0 g/cm) was blocked by an ia dose of atropine (1–5 micrograms/kg) that did not alter the sympathetic relaxation response in the trachea. In four dogs, the bronchial response to sympathetic activation was studied by intravenous (iv) bolus injection of DMPP after cholinergic blockade with atropine. DMPP (25 micrograms/kg iv) caused 9.5 +/- 2.2 g/cm bronchial relaxation, which was blocked completely by 2–4 mg/kg iv propranolol. In six other dogs, hypoxia induced by ventilation with pure nitrogen caused bronchial contraction, which was blocked by vagotomy, atropine, and hexamethonium. We report a sensitive method for selective measurement of bronchial smooth muscle response in a single resistance bronchus. This preparation preserves regional innervation and circulation and permits selective physiological stimulation in situ.

Reduced spontaneous relaxation in immature guinea pig airway smooth muscle is associated with increased prostanoid release

2008 ◽  
Vol 294 (5) ◽  
pp. L964-L973 ◽  
Author(s):  
Lu Wang ◽  
Valeria Pozzato ◽  
Graziella Turato ◽  
Aasakiran Madamanchi ◽  
Thomas M. Murphy ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Guinea Pig ◽  
Airway Smooth Muscle ◽  
Cysteinyl Leukotriene ◽  
Spontaneous Relaxation ◽  
Leukotriene Receptor ◽  
Cox 2 ◽  
Cysteinyl Leukotriene Receptor ◽  
Cox 1

Airway smooth muscle (ASM) from infant guinea pigs has less spontaneous relaxation during stimulation than ASM from adults. Inhibition of cyclooxygenase (COX), which catalyzes the production of prostanoids, increases this relaxation in infant ASM and abolishes age differences, thus suggesting that prostanoids reduce relaxation in infant ASM. In this study, we investigated whether leukotrienes are also involved in reducing spontaneous relaxation; whether the two COX isoforms, COX-1 and COX-2, differentially regulate spontaneous relaxation; and whether prostanoid release is developmentally regulated in guinea pig ASM. In different age groups, we measured relaxation during and after electrical stimulation in tracheal strips as well as prostanoid release from tracheal segments. Relaxation was studied in the absence and in the presence of a lipoxygenase inhibitor, a cysteinyl leukotriene receptor-1 antagonist, a COX-1 inhibitor, or a COX-2 inhibitor. We found that inhibition of lipoxygenase or cysteinyl leukotriene receptor-1 antagonism did not increase spontaneous relaxation at any age, thus excluding a role for leukotrienes in this phenomenon. Inhibition of COX-2, but not COX-1, promoted spontaneous relaxation. The basal release of prostanoids was more abundant in tissue from infant animals and decreased significantly with age. Thromboxane B2 was the most abundant metabolite released at all ages. Electrical stimulation and epithelium removal did not affect the age difference in prostanoid release. We conclude that increased basal prostanoid release contributes to the reduced spontaneous relaxation in immature guinea pig ASM compared with older animals. By regulating ASM relaxation, prostanoids may play a role in the airway hyperresponsiveness at a young age.

Effects of activated eosinophils cultured from human umbilical cord blood on guinea pig trachealis

1993 ◽  
Vol 265 (3) ◽  
pp. L301-L307 ◽  
Author(s):  
K. J. Hamann ◽  
M. E. Strek ◽  
S. L. Baranowski ◽  
N. M. Munoz ◽  
F. S. Williams ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Human Peripheral Blood ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Lipoxygenase Inhibitor

We studied the biochemical indexes and corresponding induction of airway smooth muscle contraction and hyperresponsiveness in guinea pig trachealis in situ caused by cultured eosinophils derived from mononuclear cell fractions of human umbilical cord blood. A method was developed that permitted isolation of large numbers of cells (approximately 2.6 x 10(6)/ml cord blood) having morphological and immunohistological characteristics of human peripheral blood eosinophils. After activation with 10(-6) M formyl-Met-Leu-Phe + 5 micrograms/ml cytochalasin B (fMLP + B), in situ application to the epithelial surface of 6 x 10(6) cord-derived eosinophils (CDE)/surface area (cm2) caused 1.46 +/- 0.24 g/cm maximal active tracheal tension in guinea pig tracheal smooth muscle (P < 0.005 vs. zero baseline). Muscarinic responsiveness also was augmented in situ in trachealis preparations treated with activated 3-wk CDE. Contraction caused by 3 x 10(-7) mol/kg iv methacholine (MCh) was 0.94 +/- 0.18 g/cm at baseline vs. 1.80 +/- 0.24 g/cm after activated CDE (P = 0.02). Control (sham-activated) 3-wk CDE caused neither significant contraction [0.41 +/- 0.16 g/cm active tension (AT); P < 0.05 vs. fMLP+B] nor augmented muscarinic responsiveness. Cells cultured for 5 wk contained fewer granules than 3-wk CDE and also caused less direct contraction of trachealis (0.73 +/- 0.14 g/cm AT) after activation (P < 0.01 vs. 3-wk CDE). Both contraction and muscarinic augmentation were blocked in 3-wk CDE after blockade of leukotriene C4 (LTC4) synthesis by pretreatment with the 5-lipoxygenase inhibitor, A63162 (50 microM). Treatment with A63162 had no effect on the stimulated release of eosinophil peroxidase.(ABSTRACT TRUNCATED AT 250 WORDS)

Optical monitoring of electrical stimulation-induced activation of in situ myenteric plexus of in situ myenteric plexus in the guinea pig jejunum

2001 ◽  
Vol 120 (5) ◽  
pp. A717-A717
Author(s):  
R BISSCHOPS ◽  
P VANDENBERGHE ◽  
E BELLON ◽  
P RAEYMAEKERS ◽  
J JANSSENS ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Guinea Pig ◽  
Myenteric Plexus ◽  
Optical Monitoring ◽  
Pig Jejunum

Optical monitoring of electrical stimulation-induced activation of in situ myenteric plexus of in situ myenteric plexus in the guinea pig jejunum

2001 ◽  
Vol 120 (5) ◽  
pp. A717 ◽  
Author(s):  
Raf Bisschops ◽  
Pieter Vanden Berghe ◽  
Erwin Bellon ◽  
Petra Raeymaekers ◽  
Jozef Janssens ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Guinea Pig ◽  
Myenteric Plexus ◽  
Optical Monitoring ◽  
Pig Jejunum

Effect of adrenergic agents on responses of smooth muscle to angiotensin

1962 ◽  
Vol 202 (5) ◽  
pp. 841-844 ◽  
Author(s):  
Philip A. Khairallah ◽  
Irvine H. Page
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Cell Membrane ◽  
Guinea Pig ◽  
Ganglion Cells ◽  
Adrenergic Nerves ◽  
Adrenergic Agents ◽  
Blocking Agents ◽  
Adrenergic Blocking ◽  
Adrenergic Blocking Agents

Evidence has been presented previously indicating that angiotensin acts indirectly on guinea pig intestines by stimulating the ganglion cells of Auerbach's plexus. Further studies have shown that the adrenergic nerves are not directly involved in this mechanism, although adrenergic blocking agents suppress the response to angiotensin, probably by acting directly on the cell membrane. Epinephrine, and to a lesser extent norepinephrine and isoproterenol, inhibited the contraction of ileum and uterus to angiotensin, and to electrical stimulation, possibly by reversing or blocking sodium or potassium ion flux across the cell membrane resulting from the action of the peptide. Most of the adrenergic blocking agents studied, with the exception of Dibenamine, also inhibited the response to angiotensin. Reserpine, guanethidine, and bretylium block its action, possibly by releasing catecholamines from bound tissue stores, and phentolamine and piperoxane, by their sympathetic actions imitating the catecholamines.

Ultrastructure, calcium accumulation, and contractile response in smooth muscle

1976 ◽  
Vol 230 (5) ◽  
pp. 1217-1224 ◽  
Author(s):  
LJ McGuffee ◽  
RM Bagby
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Guinea Pig ◽  
Vas Deferens ◽  
Contractile Response ◽  
Taenia Coli ◽  
Tetraacetic Acid ◽  
Cytoplasmic Matrix ◽  
Internal Storage ◽  
Storage Structures

After removing extracellular Ca2+ with [ethylene bis(oxyethylenenitrilo)]tetraacetic acid, we found that the guinea pig vas deferens (VD) was mechanically responsive to electrical stimulation for a significantly greater length of time than was guinea pig taenia coli (TC). An obvious explanation for these findings is that the VD has more intracellular calcium available for contraction than does the TC. To determine if this explanation is plausible, the volume of internal storage structures within the two muscles was compared. It was found that the volumes of potential sequestering structures in the VD and TC are not significantly different. Next, the affinities of the storage structures for calcium were compared. The VD was found to accumulate approximately twice as much 45Ca as did the TC, as determined by 45Ca autoradiography. Calcium-45 was present to a greater extent in association with surface vesicles, sarcoplasmic reticulum (SR), and mitochondria than in the unassociated state within the cytoplasmic matrix. Based on the results of these experiments, we suggest that the VD and the TC of the guinea pig differ in the affinity of their storage sites for calcium.

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