Characteristics of beta-adrenoceptors in tracheal smooth muscle of guinea pig sensitized by egg albumin

1987 ◽  
Vol 65 (11) ◽  
pp. 2163-2167 ◽  
Author(s):  
Akihiro Nakagoshi ◽  
Katsuo Koike ◽  
Issei Takayanagi
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Scatchard Plot ◽  
Egg Albumin ◽  
Beta Adrenoceptors ◽  
High Affinity ◽  
Partial Agonists ◽  
Isolated Trachea ◽  
Partial Blockade

The effect of pretreatment with egg albumin was examined on the beta-adrenoceptors in guinea pig isolated trachea. Befunolol and carteolol acted as partial agonists and their pA2 values were significantly larger than their corresponding pD2 values in tracheae from both untreated guinea pigs and those treated with egg albumin, suggesting that the beta-adrenoceptors contain two different affinity sites. The Scatchard plot of specific [3H]befunolol binding showed two affinity sites of the receptor (high and low affinity sites) in tracheae from both untreated animals and those treated with egg albumin. The pKD values of befunolol for both low and high affinity sites were in agreement with their respective pD2 and pA2 values. The intrinsic activities of befunolol and carteolol and the pD2 values of the test drugs were decreased by the treatment with egg albumin. The treatment with egg albumin also decreased the total amount of the two affinity sites of the receptor without any change in affinity. The present results support the partial blockade of beta-adrenoceptors in asthma proposed by Szentivanyi.

Ca2+ channel antagonist actions in bladder smooth muscle: comparative pharmacologic and [3H]nitrendipine binding studies

1985 ◽  
Vol 63 (5) ◽  
pp. 453-462 ◽  
Author(s):  
F. B. Yousif ◽  
G. T. Bolger ◽  
A. Ruzycky ◽  
D. J. Triggle
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Smooth Muscles ◽  
Affinity Binding ◽  
Induced Responses ◽  
Bladder Smooth Muscle ◽  
Binding Studies ◽  
Tonic Component ◽  
High Affinity Binding ◽  
High Affinity

The actions of a series of 15 Ca2+ channel antagonists including D-6(X), nifedipine, and diltiazem were examined against K+ depolarization and muscarinic receptor induced responses in guinea pig bladder smooth muscle. Responses of bladder are very dependent upon extracellular Ca2+ and sensitive to the Ca2+ channel antagonists, the tonic component more than the phasic component of response. Regardless of stimulant, K+ or methylfurmethide (MF), or component of response, the same rank order of antagonist activities is expressed, suggestive of a single structure–activity relationship and the existence of a single category of binding site which may, however, exist in several affinity states. High affinity binding of [3H]nitrendipine (KD = 1.1 × 10−10 M) occurs in bladder membranes, and similar high affinity binding was found in microsomal preparations from other smooth muscles including guinea pig and rat lung, rat vas deferens, uterus, and stomach. [3H]nitrendipine binding in the bladder was sensitive to displacement by other 1,4-dihydropyridines, paralleling their pharmacologic activities and showing excellent agreement with binding data previously obtained for guinea pig ileal smooth muscle. Comparison of pharmacologic data for inhibition of K+- and MF-induced responses by a common series of Ca2+ channel antagonists in bladder and ileum revealed excellent correlations. Neither pharmacologic nor binding studies suggest significant differences in Ca2+ channel antagonist properties in smooth muscle from bladder and intestine.

scholarly journals OCCURRENCE OF DELAYED HYPERSENSITIVITY DURING THE DEVELOPMENT OF ARTHUS TYPE HYPERSENSITIVITY

1958 ◽  
Vol 107 (1) ◽  
pp. 109-124 ◽  
Author(s):  
S. B. Salvin ◽  
Keyword(s):  
Lymph Node ◽  
Guinea Pig ◽  
Latent Period ◽  
Guinea Pigs ◽  
Specific Antigen ◽  
Egg Albumin ◽  
Lymph Node Cells ◽  
Type Inclusion ◽  
Antibody Determination ◽  
Circulating Antibody

Guinea pigs were injected in the footpads with either purified diphtheria toxoid or recrystallized egg albumin in Freund adjuvant without mycobacteria. Each guinea pig was then skin-tested only once with the specific antigen and bled for antibody determination. After injection of the sensitizing antigen, a latent period occurred during which neither sensitivity nor circulating antibody could be detected. A period of delayed sensitivity followed wherein circulating antibody could not be discerned and which could be transferred by lymph node cells. Ultimately, the Arthus type sensitivity developed, accompanied by circulating antibody. The duration and severity of reactions to homologous antigens during the last 2 phases varied with the antigen and with the dose. An increase in the sensitizing dose decreased the duration of the delayed type of allergy, a decrease in the dose prolonged the delayed type. Inclusion of mycobacterium in the sensitizing inoculum tended to introduce delayed sensitivity earlier and delay the onset of Arthus type sensitivity. When specific precipitate in antibody excess was included with the toxoid in the sensitizing dose, the onset of the Arthus phase was hastened. When lymph nodes from a large number of sensitized donors were removed during the latter part of the latent period, recipients of the cells showed a delayed type sensitivity.

Smooth muscle cells from guinea pig stomach possess high-affinity galanin receptors that mediate relaxation

1994 ◽  
Vol 266 (5) ◽  
pp. G839-G845 ◽  
Author(s):  
Z. F. Gu ◽  
T. K. Pradhan ◽  
D. H. Coy ◽  
R. T. Jensen
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Maximal Effect ◽  
Dependent Manner ◽  
High Affinity ◽  
Gastric Smooth Muscle ◽  
Guinea Pig Stomach ◽  
Galanin Receptors

Galanin-like immunoactivity occurs in nerves and plexi in muscle layers throughout gastrointestinal tract including the stomach. Galanin can affect gastric emptying and contraction or relaxation of gastric muscle in different species. The aim of this study was to investigate the direct effect of galanin on dispersed gastric smooth muscle cells and to characterize any galanin receptors that mediated any effect. Dispersed gastric smooth muscle cells were prepared from guinea pig stomach by collagenase digestion. Porcine galanin (p-galanin; 1 microM) did not stimulate contraction when present alone; however, p-galanin (1 microM) inhibited carbachol-induced contraction with a half-maximal effect at 7 nM. p-Galanin (1 microM) increased cellular adenosine 3',5'-cyclic monophosphate (cAMP) content by 10 s and caused a maximal increase of 80% over basal. 125I-galanin (porcine) bound to dispersed cells in a time- and temperature-dependent manner. Binding was saturable, reversible, and specific. Binding of 125I-galanin was inhibited almost equally by porcine and rat galanin (Ki = 6-8 nM) but was not inhibited by the galanin-associated peptide [preprogalanin-(108-123)]. The fragment galanin-(1-16) was equally potent to rat galanin; however, the fragment galanin-(9-29) was 56-fold less potent (Ki = 370 nM). Computer analysis demonstrated there were two binding sites for p-galanin on gastric smooth muscle cells, a high-affinity site (Kd = 2.6 nM) with low capacity (Bmax = 175 fmol/mg protein) and a low-affinity site (Kd = 150 nM) with large capacity (Bmax = 3,611 fmol/mg protein).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of interactions of R-(+)- and S-(−)-isomers of β-adrenergic partial agonists, befunolol and carteolol, with high affinity site of β-adrenoceptors in isolated rabbit ciliary body and guinea-pig taenia caeci

1991 ◽  
Vol 69 (7) ◽  
pp. 951-957 ◽  
Author(s):  
Katsuo Koike ◽  
Hisashi Hagiwara ◽  
Issei Takayanagi
Keyword(s):  
Cyclic Amp ◽  
Guinea Pig ◽  
Binding Site ◽  
Ciliary Body ◽  
Partial Agonist ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity ◽  
Partial Agonists ◽  
High Affinity Binding Site

The stereoselectivities of β-adrenergic partial agonists for the high affinity binding site of β-adrenoceptors in the rabbit ciliary body and the guinea-pig taenia caeci were studied. The pA2 values of the S-(−)-isomers of befunolol and carteolol against S-(−)-isoprenaline, which were calculated from the shift of each concentration–response curve in increasing cyclic AMP levels, were significantly larger than those of the R-(+)-isomers in the guinea-pig taenia caeci, while the pA2 values of the S-(−)-isomers were not significantly larger than those of the R-(+)-isomers in the rabbit ciliary body. The pKi values determined from the binding experiments were in good agreement with the pA2 values from the increases in cyclic AMP levels. These results suggest that the high affinity binding site of β-adrenoceptors in the guinea-pig taenia caeci may be able to discriminate stereoselectively between the R-(+)- and S-(−)-isomers, while in the rabbit ciliary body there is no stereoselectivity between the two enantiomers.Key words: stereoselectivity, β-adrenoceptor, partial agonist, rabbit ciliary body, guinea-pig taenia caeci.

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.

scholarly journals Phenylethylamine effects on histamine-induced contraction of isolated guinea-pig trachea rings

2005 ◽  
Vol 24 (2) ◽  
pp. 95-97
Author(s):  
Gvozden Rosic ◽  
Zorica Lazic ◽  
Suzana Pantovic ◽  
Mirko Rosic
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Muscle Tone ◽  
Tracheal Smooth Muscle ◽  
Competitive Antagonist ◽  
Methyl Transferase ◽  
Basal Tone ◽  
H3 Receptors ◽  
Isolated Trachea ◽  
Histamine Methylation

Histamine produces constriction of tracheal smooth muscle via H1 receptors, but it also decreases tracheal smooth muscle tone via H2 and H3 receptors. In addition, it has already been reported that phenylethylamine is competitive antagonist of histamine N-methyl-transferase (HMT), enzyme responsible for rapid inactivation of histamine. Our results suggest possibility that phenylethylamine as competitive antagonist of histamine N-methyl-transferase leads to potentiation of histamine induced constriction of isolated guinea-pig trachea, which could be consequence of decreased histamine methylation and subsequent histamine inactivation. At the same time, phenylethylamine had no direct effect on basal tone of intact isolated trachea rings, as well as on other mechanisms leading to increased responsiveness of guinea-pig tracheal smooth muscle (acetylcholine, KCl, electro stimulation).

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