Stimulation frequency-dependent nonadrenergic noncholinergic airway responses of the guinea pig

1991 ◽  
Vol 70 (3) ◽  
pp. 1006-1010 ◽  
Author(s):  
C. S. Venugopalan ◽  
E. P. Holmes ◽  
V. Fucci ◽  
A. J. Guthrie
Keyword(s):  
Guinea Pig ◽  
Adrenergic Blockade ◽  
Frequency Dependent ◽  
Insufflation Pressure ◽  
Peripheral Airway ◽  
Inhibitory Components ◽  
Airway Responses ◽  
Nanc Innervation

We examined the inhibitory and excitatory components of the nonadrenergic noncholinergic (NANC) innervation of the guinea pig airways by in vivo and in vitro methods. Electrical stimulation of the vagus in chloralose-urethan-anesthetized guinea pigs after cholinergic and adrenergic blockade produced peripheral airway constriction (insufflation pressure) and tracheal relaxation (pouch pressure). Vagal stimulation was applied for 90 s at 5-V pulses of 2-ms duration at frequencies of 5, 15, 25, and 35 Hz in each group (n = 6). The pouch relaxation peaked at 15 Hz. The insufflation pressure was highest at 5 Hz. Field stimulations of the same frequencies were applied on tracheal spirals and lung parenchymal strips. The maximal relaxation of the trachea occurred at 15-35 Hz. The lung parenchymal strip tensions increased almost linearly as the frequency increased from 5 to 35 Hz. The results of the study indicated a frequency-dependent response for both excitatory and inhibitory components of the NANC, which operate at different frequencies for optimal responses.

scholarly journals Bronchial responses to substance P after antigen challenge in the guinea-pig: in vivo and in vitro studies

1992 ◽  
Vol 1 (3) ◽  
pp. 207-212 ◽  
Author(s):  
E. Boichot ◽  
V. Lagente ◽  
G. Le Gall ◽  
C. Carré ◽  
J. M. Mencia-Huerta ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Bronchial Hyperresponsiveness ◽  
Neutral Endopeptidase ◽  
Antigen Challenge ◽  
Control Groups ◽  
Airway Responses

The effect of antigen challenge on the airway responses to substancePand on the epithelial neutral endopeptidase (NEP) activity was investigated in aerosol sensitized guinea-pigs. In vivo, bronchial responses to aerosolized substancePwere similar to the responses observed in antigen-challenged guinea-pigs and in the control groups. In contrast, when the guinea-pigs were pretreated with the NEP inhibitor, phosphoramidon, a significant increase in the airway responses to substancePwas observed after antigen challenge in vivo. However, in vitro, the contractile responses of the tracheal smooth muscle to substancePwere similar between groups of guinea-pigs, in respect to the presence or absence of the epithelium and/or phosphoramidon. Histological studies showed an accumulation of eosinophils in the tracheal submucosa after antigen challenge and intact epithelial cells. These results show that in vivo bronchial hyperresponsiveness to substancePafter antigen challenge in the guinea-pig is not associated with increased responses of the smooth muscle to exogenousSPin vitro. In addition, the results with phosphoramidon suggest that loss of NEP activity cannot account for the in vivo bronchial hyperresponsiveness to substancePpresently observed.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

The control of trophoblastic growth in the guinea pig

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 405-418
Author(s):  
E. B. Ilgren
Keyword(s):  
Guinea Pig ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
The Other ◽  
In Vivo Analysis

The growth of mouse trophectoderm depends upon the presence of the inner cell mass. Whether this applies to other species of mammals is not known. To investigate this problem, the guinea pig was selected for two reasons. Firstly, the growth of guinea-pig trophoblast resembles that of man. Secondly, earlier studies suggest that the proliferation of guinea-pig trophectoderm may not be under ICM control. Therefore, in the present study, the guinea-pig blastocyst was cut microsurgically to yield two tissue fragments. These contained roughly equal numbers of trophectodermal cells, one fragment being composed only of trophectoderm and the other containing ICM tissue as well. Subsequently, the growth of these mural and polar fragments was followed in vitro since numerous technical difficulties make an in vivo analysis of this problem impracticable. In a manner similar to the mouse, the isolated mural trophectoderm of the guinea pig stopped dividing and became giant. In contrast, guinea-pig polar fragments formed egg-cylinder-like structures. The latter contained regions structurally similar to two presumptive polar trophectodermal derivatives namely the ectoplacental and extraembryonic ectodermal tissues. These findings suggest that guinea-pig trophectodermal growth may occur in a manner similar to the mouse and thus be under ICM control.

scholarly journals Reversible neutralization by congo red of the anthracidal power of serum

1937 ◽  
Vol 37 (3) ◽  
pp. 471-473 ◽  
Author(s):  
J. Gordon ◽  
N. Wood
Keyword(s):  
Guinea Pig ◽  
Congo Red ◽  
Inhibitory Action ◽  
Protein Solutions ◽  
Haemolytic Activity ◽  
In Vitro Experiments ◽  
Serum Complement ◽  
Destructive Effect

In earlier papers (Gordon, 1930) it was shown that congo red has an inactivating effect on serum complement, both haemolytic and bactericidal, and that this effect can be reversed by treating the serum and congo red mixture with charcoal, the charcoal removing the congo red and leaving the complement active again. A similar reversal of inactivation is obtained by using instead of the charcoal, heated serum (55° C. for 30 min.) or protein solutions. Later (Gordon, 1931), it was shown that congo red had an inactivating effect on the haemolysins of Streptococcus haemolyticus and B. welchii. The reversibility of this effect was not so easy to demonstrate as with complement. Charcoal had a destructive effect on the haemolysins and so could not be used. It was found, however, that when the concentration of congo red was just sufficient to neutralize the streptococcal haemolysin, the addition of cuprammonium artificial silk adsorbed the congo red and liberated the haemolysin. In the case of B. welchii this method of reversal was not suitable, as the artificial silk had a destructive effect on the haemolysin. Instead, reversibility was demonstrated by adding ox serum to the mixture of congo red and haemolysin. This brought about a redistribution of the congo red between the ox serum and the haemolysin and if the amount of congo red used had been only just sufficient to neutralize the haemolysin of B. welchii, then the haemolytic activity could again be demonstrated. Gordon and Robson (1933) showed that congo red interfered with the anaphylactic reaction tested both in vivo and in vitro, the guinea-pig uterus being used in the in vitro experiments, in which the inhibitory action of the dye was shown to be reversible. It was suggested that the congo red interfered with the entrance of antigen into the cell.

Protective role of epithelium in the guinea pig airway

1989 ◽  
Vol 66 (4) ◽  
pp. 1547-1552 ◽  
Author(s):  
M. Munakata ◽  
I. Huang ◽  
W. Mitzner ◽  
H. Menkes
Keyword(s):  
Guinea Pig ◽  
Protective Role ◽  
Airway Epithelial ◽  
Serosal Side ◽  
Epithelial Surface ◽  
Airway Responses ◽  
Airway Tone ◽  
Stimulation Of

We developed an in vitro system to assess the role of the epithelium in regulating airway tone using the intact guinea pig trachea (J. Appl. Physiol. 64: 466–471, 1988). This method allows us to study the response of the airway when its inner epithelial surface or its outer serosal surface is stimulated independently. Using this system we evaluated how the presence of intact epithelium can affect pharmacological responsiveness. We first examined responses of tracheae with intact epithelium to histamine, acetylcholine, and hypertonic KCl when stimulated from the epithelial or serosal side. We then examined the effect of epithelial denudation on the responses to these agonists. With an intact epithelium, stimulation of the inner epithelial side always caused significantly smaller changes in diameter than stimulation of the outer serosal side. After mechanical denudation of the epithelium, these differences were almost completely abolished. In the absence of intact epithelium, the trachea was 35-fold more sensitive to histamine and 115-fold more sensitive to acetylcholine when these agents were applied to the inner epithelial side. In addition, the presence of an intact epithelium almost completely inhibited any response to epithelial side challenge with hypertonic KCl. These results indicate that the airway epithelial layer has a potent protective role in airway responses to luminal side stimuli, leading us to speculate that changes in airway reactivity measured in various conditions including asthma may result in part from changes in epithelial function.

Vasopressin is metabolized by a trypsinlike enzyme in guinea pig amniotic fluid

1989 ◽  
Vol 257 (3) ◽  
pp. E354-E360 ◽  
Author(s):  
C. F. Uyehara ◽  
A. K. Sato ◽  
J. R. Claybaugh
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Guinea Pig ◽  
Amniotic Fluid ◽  
High Pressure Liquid Chromatography ◽  
Trypsin Inhibitor ◽  
Arginine Vasopressin ◽  
Proteolytic Enzyme

We have demonstrated that arginine vasopressin (AVP) is degraded to desglycinamide AVP by a trypsinlike enzyme found in guinea pig amniotic fluid. Incubation of [3H]AVP with guinea pig amniotic fluid in vivo or in vitro produced a metabolite that comigrated on high-pressure liquid chromatography with desglycinamide AVP in three different buffer systems. Also, AVP antisera that cross-reacted with standard desglycinamide AVP could detect this amniotic fluid metabolite. Because the enzyme responsible for the cleavage of glycinamide from AVP was likely to be trypsin, experiments with aprotinin, a trypsin inhibitor, were conducted. Results demonstrated that the production of the amniotic fluid AVP metabolite could be completely blocked in the presence of the trypsin inhibitor. In addition, examination of amniotic fluid collected from fetuses in the second half of gestation (term = 68 days) showed that AVP could not be metabolized to desglycinamide AVP until after 52 days of gestation. In conclusion, AVP appears to be metabolized by a trypsinlike enzyme in amniotic fluid, and because trypsin is a general proteolytic enzyme, the amniotic compartment may also serve as a clearance site for other proteins.

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