Species differences in pulmonary vasoactive responses to histamine, 5-hydroxytryptamine, and KCl

1993 ◽  
Vol 74 (1) ◽  
pp. 139-146 ◽  
Author(s):  
J. D. Bradley ◽  
P. B. Zanaboni ◽  
T. E. Dahms
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Species Differences ◽  
Venous Occlusion ◽  
Longitudinal Distribution ◽  
Critical Closing Pressure ◽  
Before And After ◽  
Pulmonary Arterial ◽  
Microvascular Resistance

Species differences in the longitudinal distribution of pulmonary vascular resistance (PVR) in response to 5-hydroxytryptamine (5-HT) or histamine (His) may be attributed to variations in the distribution of functional smooth muscle between arteries and veins estimated by the response to KCl. Isolated dog, guinea pig, or rabbit lungs were perfused at a constant flow = 55–75 ml.min-1.kg body wt-1. Pulmonary arterial (Ppa); arterial, double, and venous occlusion (Po,a; Pdo; Po,v, respectively); and pulmonary venous (Ppv) pressures were measured before and after increasing PVR by infusing His, 5-HT, or KCl. 5-HT and His increased Ppa--Pdo in rabbits but Pdo--Ppv in guinea pigs. In dogs, 5-HT increased Ppa--Po,a, but His increased Pdo--Ppv. Dynamic (Co,v) and static vascular compliance (CP-Q), as well as critical closing pressure (Pcc, the gamma-intercept of pressure-flow curves), were also measured. At baseline, Co,v was the same among species. However, CP-Q was higher than Co,v in all lungs and was significantly different among species in order of (in ml.cmH2O-1.100 g-1) rabbit (4.54 +/- 0.28) > guinea pig (3.31 +/- 0.18) > dog (2.21 +/- 0.13). Increases in Pcc correlated with increases in microvascular resistance (Po,a--Po,v) but not with increases in PVR after agonist infusion. KCl responses suggest that guinea pigs and rabbits have relatively more functional smooth muscle in venous and arterial microvessels, respectively, whereas dogs have approximately equal amounts.(ABSTRACT TRUNCATED AT 250 WORDS)

Responsiveness of and interactions between airways and tissue in guinea pigs during induced constriction

1993 ◽  
Vol 74 (6) ◽  
pp. 2848-2854 ◽  
Author(s):  
T. Nagase ◽  
T. Ito ◽  
M. Yanai ◽  
J. G. Martin ◽  
M. S. Ludwig
Keyword(s):  
Mechanical Ventilation ◽  
Smooth Muscle ◽  
Guinea Pig ◽  
Tidal Volume ◽  
Airway Smooth Muscle ◽  
Guinea Pigs ◽  
Positive End Expiratory Pressure ◽  
Ventilation Frequency ◽  
Low Concentrations ◽  
Before And After

Mechanical interdependence between airways and tissues can modify the magnitude of induced bronchoconstriction. We questioned whether the guinea pig, an animal with abundant airway smooth muscle, would differ from other species in the relative responsiveness of and interactions between airways and tissues. Therefore we induced constriction with aerosolized methacholine (MCh) and partitioned responses into airway and tissue components. We measured tracheal and alveolar pressures using alveolar capsules in open-chest guinea pigs (n = 9) during mechanical ventilation [frequency = 1 Hz, tidal volume = 6 ml/kg, positive end-expiratory pressure (PEEP) = 5 cmH2O] and calculated the resistance of lung (RL), tissue (Rti), and airway (Raw) before and after administration of aerosols of MCh in progressively doubling concentrations (0.063–16 mg/ml). In separate animals (n = 10), measurements were made at 3–13 cmH2O PEEP. After aerosols of saline and MCh (0.125-32 mg/ml), measurements were repeated at 3, 7, and 11 cmH2O PEEP. At submaximal levels of constriction, the airways and lung tissues demonstrated similar responsiveness. Increasing PEEP increased RL and Rti and decreased Raw under baseline conditions. At low concentrations of MCh, increasing PEEP increased RL but decreased RL at the highest concentration. Increases in PEEP significantly increased Rti at all concentrations of MCh but decreased Raw only at 8 mg/ml of MCh. These observations demonstrate that, in guinea pigs, during submaximal constriction, airways and tissues behave similarly; moreover, airway-parenchymal interdependence is important in determining the level of bronchoconstriction.

SPECIES DIFFERENCES IN THE DEOXYRIBONUCLEIC AND RIBONUCLEIC ACID CONTENTS OF LIVERS OF NON-PREGNANT AND PREGNANT MICE, GUINEA-PIGS AND CATS

1953 ◽  
Vol 9 (1) ◽  
pp. 45-51 ◽  
Author(s):  
ROSA M. CAMPBELL ◽  
H. W. KOSTERLITZ
Keyword(s):  
Guinea Pig ◽  
Protein Content ◽  
Liver Cell ◽  
Ribonucleic Acid ◽  
Guinea Pigs ◽  
Deoxyribonucleic Acid ◽  
Species Differences ◽  
Liver Cells ◽  
Maternal Liver ◽  
Pregnant Mice

1. The protein content of liver cells is almost independent of the size of the animal (mice, cats and previous results on rats, Campbell & Kosterlitz [1949]), and varies with the amount of protein eaten. 2. As has already been shown for rats, the ribonucleic acid ('RNA') content of the liver cells of non-pregnant mice, guinea-pigs and cats varies directly with the protein content of the cells. For a given protein content the mouse and rat have more RNA than the guinea-pig and cat. 3. During pregnancy there is a rise of the deoxyribonucleic acid ('DNA') content of the livers and in the protein content of the liver cells of mice (and rats), but not of guinea-pigs. 4. An excess of RNA over that predicted from the protein content of the liver cell has previously been found for the rat during pregnancy, and ascribed to the action of a placental factor on the maternal liver. A similar excess of RNA has now been observed in the mouse and, to a less extent, in the guinea-pig. It appears to be absent in the cat. 5. Possible causes of some of these species differences are considered.

Effects of initial length on intrinsic tone in guinea pig tracheal smooth muscle

1998 ◽  
Vol 275 (6) ◽  
pp. L1026-L1030 ◽  
Author(s):  
Martin Bard ◽  
Sergio Salmeron ◽  
Catherine Coirault ◽  
Francois-Xavier Blanc ◽  
Yves Lecarpentier
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Isometric Force ◽  
Muscle Length ◽  
Tracheal Smooth Muscle ◽  
Before And After ◽  
Active Nature ◽  
The Difference ◽  
Resting Tone ◽  
The Relationship

In the guinea pig, tracheal smooth muscle (TSM) exhibits intrinsic tone (IT). The active nature of IT suggests that it could be influenced by muscle length and load. In the guinea pig, IT is entirely suppressed by the cyclooxygenase inhibitor indomethacin. IT could be measured as the difference between resting tone before and after indomethacin addition. We examined, in electrically stimulated TSM strips ( n= 9), the influence of initial muscle length ( L i) on IT, the relationship between IT and the maximum extent of relaxation (ΔF1), and the influence of indomethacin on active isometric force. When L i decreased from 100 to 75% of optimal L i, there was a significant decrease in IT (from 12.0 ± 0.2 to 5.3 ± 0.1 mN; P < 0.001). Over the range of L i studied, ΔF1 underestimated the amount of IT, but there was a close linear relationship between ΔF1 and IT ( r = 0.9). Compared with the basal state, indomethacin increased active isometric force (from 9.5 ± 1.0 to 19.7 ± 2.0 mN at optimal L i; P < 0.001) and induced its length dependency. In guinea pig TSM, L i was an important determinant of IT.

scholarly journals Phasic and Tonic Smooth Muscle Function of the Partially Obstructed Guinea Pig Intestine

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jingbo Zhao ◽  
Donghua Liao ◽  
Jian Yang ◽  
Hans Gregersen
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Muscle Function ◽  
Circumferential Stress ◽  
Outer Diameter ◽  
Dependent Manner ◽  
Contraction Force ◽  
Jejunal Segment ◽  
Smooth Muscle Function

This study was to generate phasic and tonic stress-strain curves for evaluation of smooth muscle function in the obstructed guinea pig jejunum. Partial and sham obstruction of the jejunum in guinea pigs was created surgically, with guinea pigs not being operated on served as normal controls. The animals survived 2, 4, 7, and 14 days, respectively. The jejunal segment was distended to 10 cm H2O. The pressure and outer diameter changes were recorded. Passive conditions were obtained by using papaverine. Total phasic, tonic, and passive circumferential stress and strain were computed from the diameter and pressure data with reference to the zero-stress-state geometry. The active phasic and tonic stresses were defined as the total phasic and tonic stress minus the passive stress. The thickness of intestinal muscle layers increased in a time-dependent manner after obstruction. The amplitude of passive, total phasic, total tonic, active phasic, and active tonic circumferential stresses increased as function of strain 7 days after obstruction. However, when normalized to muscle layer thickness, the amplitude of active stresses did not differ among the groups. In conclusion, the long-term-obstructed intestine exhibits increased total smooth muscle contraction force. However, the contraction force per smooth muscle unit did not increase.

Changes of gap junctions in myometrium of guinea pig at parturition and abortion

1982 ◽  
Vol 60 (3) ◽  
pp. 335-341 ◽  
Author(s):  
R. E. Garfield ◽  
E. E. Daniel ◽  
M. Dukes ◽  
J. D. Fitzgerald
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Gap Junctions ◽  
Gap Junction ◽  
Electron Micrographs ◽  
Guinea Pigs ◽  
Muscle Cells ◽  
Similar Increase ◽  
Junction Area

Myometrial tissues from guinea pigs were quantitatively examined for gap junctions in electron micrographs. Small numbers of gap junctions were present between smooth muscle cells in myometria of pregnant guinea pigs at days 50 and 65 of gestation. The junctions increased in number and size at parturition on day 69 and decreased again to control levels 24 h after parturition. A similar increase in junctions occurred when abortion was induced by 16,16-dimethylprostaglandin E2 (PGE2) on day 65. There were no consistent or significant differences in numbers of gap junctions from myometrium taken over sites of placental attachment and from other sites. These results together with previous studies suggest that an increase in myometrial gap junction area is associated with and may be essential for parturition in guinea pigs, but the control of their development may differ from that in other mammals.

Benign Mesenchymoma of the Heart in the Guinea Pig

1968 ◽  
Vol 5 (2) ◽  
pp. 97-101 ◽  
Author(s):  
Robert F. McConnell ◽  
Raymond D. Ediger
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
The Other ◽  
Breeding Colony ◽  
Muscle Tissues ◽  
Single Mass

Thirty-six hundred ninety-eight guinea pigs of the Dunkin-Hartley strain from the breeding colony at Fort Detrick were necropsied. Four females had mesenchymomas of the heart. The tumors were similar histologically and were composed of multiple benign mesenchymal tissues which were amalgamated into a single mass. One tumor was composed of fibrous, angiomatous, adipose, cartilagenous, osscous, hematopoietic, myxomatous, and possibly smooth muscle tissues. Smooth muscle and myxomatous tissues were not found in the other tumors. All were benign and probably originated from the primitive mesenchyme of the heart.

Effect of chronic hypoxia on pulmonary vascular pressures in isolated lungs of newborn pigs

1994 ◽  
Vol 77 (6) ◽  
pp. 2853-2862 ◽  
Author(s):  
C. D. Fike ◽  
M. R. Kaplowitz
Keyword(s):  
Smooth Muscle ◽  
Arterial Pressure ◽  
Chronic Hypoxia ◽  
Pulmonary Arterial Pressure ◽  
Muscle Tone ◽  
Before And After ◽  
Alveolar Hypoxia ◽  
Pulmonary Arterial ◽  
Newborn Pigs ◽  
Isolated Lungs

Our purposes were to determine whether chronic alveolar hypoxia altered pulmonary vascular pressures in lungs of newborn pigs, evaluate the contribution of smooth muscle tone to alterations in pulmonary vascular pressures, and examine whether chronic hypoxia altered pulmonary vascular reactivity to acute hypoxia. We kept 24- to 72-h-old pigs in chambers filled with room air (control) or 11–12% O2 (chronic hypoxia) for either 3–5 (short) or 10–12 (long) days. We used isolated lungs and applied micropuncture and vascular occlusion techniques to measure pressure in 10- to 30-microns-diam venules and inflow occlusion and outflow occlusion pressures before and after the addition of the smooth muscle dilator papaverine or before and after inflation of the lungs with a hypoxic gas mixture. For pigs in both the short and long groups, pulmonary arterial pressure was the only vascular pressure that was greater in chronically hypoxic than in control lungs. Increased smooth muscle tone was the primary source of the change in pulmonary arterial pressure with short hypoxia, whereas morphometric changes contributed to the change in pulmonary arterial pressure with long hypoxia. Exposure of newborn pigs to different lengths of alveolar hypoxia is a useful model to study postnatal pulmonary hypertension in newborns and infants.

Hyperbaric Compression in the Guinea Pig with Perilymph Fistula

2003 ◽  
Vol 129 (3) ◽  
pp. 259-264 ◽  
Author(s):  
Paige E. Lindberg ◽  
G. Joseph Parell ◽  
Byron J. Gajewski ◽  
Angela R. Prevatt ◽  
Patrick J. Antonelli
Keyword(s):  
Hearing Loss ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Vestibular Function ◽  
Relative Safety ◽  
Before And After ◽  
Tube Dysfunction ◽  
Compression Treatment ◽  
Hyperbaric Therapy ◽  
To Receive

OBJECTIVE: The study goal was to evaluate the effects of hyperbaric therapy on the auditory and vestibular function of guinea pigs compromised by perilymph fistula (PLF). METHODS: Twenty-four pigmented guinea pigs underwent induction of bilateral eustachian tube dysfunction before the creation of a unilateral PLF. Half of the animals were randomly assigned to receive immediate hyperbaric compression treatment of 4 “dives” each. Hearing was tested electrocochleographically, and signs of vestibulopathy were recorded before and after compression. RESULTS: After accounting for the effects of PLF, compression was not associated with significant hearing loss ( P = 0.5411). Vestibulopathy was seen only in ears with PLF, and its incidence was similar for compression and noncompression groups. CONCLUSION: Hyperbaric compression does not compromise auditory or vestibular function in guinea pig ears with experimental PLF. SIGNIFICANCE: Our observations support the relative safety of recompression in patients with PLF.

Effect of mode of activation of human eosinophils on tracheal smooth muscle contraction in guinea pigs

1993 ◽  
Vol 264 (5) ◽  
pp. L475-L481
Author(s):  
M. E. Strek ◽  
S. R. White ◽  
T. R. Hsiue ◽  
G. V. Kulp ◽  
F. S. Williams ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Human Peripheral Blood ◽  
Total Content ◽  
Smooth Muscle Contraction ◽  
Tracheal Smooth Muscle ◽  
Kinetic Assay ◽  
Lipoxygenase Pathway ◽  
Threshold Response

We studied the relationship between mode of activation of isolated human eosinophils and in situ responsiveness in isolated tracheal smooth muscle (TSM) of guinea pigs. Human peripheral blood eosinophils were activated with either 10(-7) M phorbol myristate acetate (PMA) or 10(-6) M formyl-methionyl-leucyl-phenylalanine (fMLP) + 5 micrograms/ml cytochalasin B (CYB), and activation was confirmed by measurement of eosinophil peroxidase (EPO) secretion by kinetic assay. EPO secretion was similar after activation with fMLP+CYB (10.2 +/- 3.2% of total eosinophil content) and PMA (10.0 +/- 2.8% of total content; P = NS). Topical application of 6 x 10(6) eosinophils/cm2 activated with fMLP+CYB to the TSM segment caused 0.51 +/- 0.14 g/cm active tension (AT) in five preparations (P < 0.03 vs. baseline); cells activated with PMA caused no contractile response (0.04 +/- 0.03 g/cm AT, P = NS vs. baseline). Both PMA- and fMLP+CYB-activated cells caused augmentation of muscarinic responsiveness of guinea pig trachealis. The dose of intravenous acetylcholine required to cause a threshold response (ED0.3) was -7.3 +/- 0.1 log mol/kg at baseline vs. -8.7 +/- 0.5 log mol/kg after treatment with fMLP+CYB-activated eosinophils (P = 0.05) and -6.9 +/- 0.1 log mol/kg at baseline vs. -7.5 +/- 0.1 log mol/kg after PMA-activated cells (P < 0.01). Both AT and augmented muscarinic responsiveness were blocked by pretreating the eosinophils with 200 microM A-63162, an inhibitor of 5-lipoxygenase, before activation with fMLP+CYB. We demonstrate that eosinophils activated comparably (as assessed by EPO secretion) cause augmented muscarinic responsiveness and/or direct contraction of guinea pig TSM through secretion of a product of the 5-lipoxygenase pathway.(ABSTRACT TRUNCATED AT 250 WORDS)

EFFECTS OF OVARIAN STEROIDS AND PROLACTIN ON THE CONTRACTILITY AND SODIUM PUMP SITE DENSITY OF GUINEA-PIG MYOMETRIUM

1978 ◽  
Vol 77 (1) ◽  
pp. 43-48 ◽  
Author(s):  
A. LIPTON ◽  
J. LEAH ◽  
H. C. PARKINGTON
Keyword(s):  
Single Dose ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Incubation Medium ◽  
Sodium Pump ◽  
Ovarian Steroids ◽  
Myometrial Cell ◽  
Site Density ◽  
Before And After ◽  
Myometrial Contractility

Ovariectomized guinea-pigs were given a single dose of oestrogen or progestogen or the two steroids combined. Controls were given 0·9% saline. Four days after the injection, myometrial contractility in response to spasmogens was measured isometrically in isolated tissue baths, both before and after incubation in Kreb's solution with or without added prolactin. Further myometrial strips were also incubated with or without prolactin and the density of Na+/K+ ATPase 'pump' sites on the surface of the myometrial cell was estimated by labelling with tritiated ouabain. Incubation with prolactin significantly reduced the contractility of myometrial tissue from guinea-pigs given saline alone, progestogen alone or progestogen plus oestrogen, but not in tissue from animals pretreated with oestrogen. When myometrial strips from animals pretreated with oestrogen or progestogen were incubated without prolactin in the medium, there was a significant increase in the density of pump sites compared with the number in saline-pretreated animals; incubation with prolactin did not further modify this effect. When both steroids were administered together there was a significant increase only when prolactin was present in the incubation medium. There was also a significant increase in the density of pump sites after incubation of myometrium from the control (saline-pretreated) animals in the presence of prolactin.

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