Time-dependent observations of secretion marker levels in nasal secretion after histamine and methacholine provocations

Nasal provocation tests with histamine and methacholine were carried out on 25 healthy men in an effort to assess the dynamic changes of albumin, total IgA, secretory IgA and lactoferrin concentrations in the nasal secretion. The trials were performed with 0.5, 1, and 4 mg of histamine and 8, 16, and 32 mg of methacholine. Each dose of histamine or methacholine was sprayed into the nose every 2nd day, with two days' interval between the two provoking agents. Nasal secretions were collected after saline spraying only, forming the baseline group, after 3, 10 and 15 min of administration of the challenge agent. The baseline levels presented the following values: for albumin 257 +/- 230 microg/ml, secretory IgA 608 +/- 379 microg/ml, total IgA 1025 +/- 423 micog/ml, and lactoferrin 213 +/- 156 microg/ml. The increase in albumin level after nasal provocation, particularly significant after histamine administration (to 3713 +/- 2311 microg/ml), indicates incessant protein plasma leakage from the blood circulation to the nasal secretion. After administration of both provocating agents, there was a significant gradual decrease in secretory IgA level, even below the baseline value. After the 2nd and 3rd doses of methacholine and histamine spray, the concentration of secretory IgA decreased by 2-3 times and was found to be 200-300 microg/ml, respectively. Also, lactoferrin concentration values decreased gradually after the 2nd and 3rd doses of methacholine and histamine to levels close the baseline value. These observations suggest a time- and dose-dependent, non-specific dysfunction of local immunity response after nasal provocations.     

The effects of peptides and mediators on mucus secretion rate and smooth muscle tone in the ferret trachea

The effects of a number of peptides and mediators were measured on the secretion rate of tracheal mucus and tracheal smooth muscle tone in the ferretin vitro whole trachea.The comparison of secretion rate and smooth muscle tone, measured simultaneously in the same preparation, shows that there are wide differences in sensitivity between the two systems; there appears to be no relationship between mucus volume output and smooth muscle contraction.The comparison of mucus secretion rate and glycoprotein output in other models and species to these drugs in the same concentrations indicates that there may be mucus glycoprotein output without an increase in volume output.     

Comparative protective effect of the inhaled beta 2-agonist salbutamol (albuterol) on bronchoconstriction provoked by histamine, methacholine, and adenosine 5'-monophosphate in asthma

We have investigated the ability of salbutamol to protect against bronchoconstriction induced by methacholine, histamine, and adenosine 5'-monophosphate (AMP) in nine subjects with asthma. In a double-blind, placebo-controlled study, salbutamol, 2.5 mg administered by nebulization, increased the geometric mean provocation concentrations of methacholine, histamine, and AMP required to produce a 20% decrease in FEV1 from 0.3 to 2.2, 0.4 to 3.8, and 4.0 to 106.7 mg/ml after placebo and active treatment, respectively (p less than 0.01). Thus, this dose of beta 2-adrenoceptor agonist displaced the concentration-response curves for methacholine, histamine, and AMP to the right in a parallel fashion by 8.8 (0.6 to 29.3)-, 10.3 (1.4 to 33)-, and 26.6 (1.5 to 76.6)-fold, respectively, the difference between the results for AMP and those for histamine and methacholine being statistically significant (p less than 0.01). For six of the nine subjects studied, salbutamol displaced the concentration-response curve for AMP to the right by greater than 50-fold. There was no correlation between bronchodilatation and protection against bronchoconstriction induced by any of the agonists. We conclude that salbutamol protects against bronchoconstriction provoked by methacholine and histamine by functional antagonism, whereas with AMP, an additional activity is demonstrable, possibly involving inhibition of mast cell-mediator release.     

The interaction of cholinomimetics,peptides and compounds 48/80 on histamine secretion from the mast cell

The mechanism of selective, non-immunological histamine release from mast cells, caused by various endogenous substances, is not clearly understood. Sincein vivo experiments indicate that the local control of secretory cells is influenced by acetylcholine and peptides, we investigated whether the secretion of histamine is similarly regulated in the mast cell. Experiments were performed with peritoneal cavity cell suspensions (PCS) of the rat. The endogenous polypeptide substance P, compound 48/80 and a non-hydrolysable cholinomimetic agonist, carbachol, were used. The concentrations of the drugs were kept low to avoid non-specific histamine release caused by morphological damage of mast cells. It was found that: (1) carbachol (2×10^–5 M) did not release histamine from PCS, (2) substance P (6.5×10^–6 M) released histamine and this effect was increased by the addition of carbachol (2×10^–5 M); the effect of carbachol was inhibited by atropine, (3) carbachol (2×10^–5 M) did not increase histamine release caused by compound 48/80 (0.02 g/ml).From these experiments it may be concluded that activation of peptidergic receptor(s) can cause histamine release from mast cells and that muscarinic agents may be involved in the regulation of the(se) receptor(s).     

Effects of methacholine and uridine 5'-triphosphate on tracheal mucus rheology in mice

We compared the action of methacholine (MCh) and uridine 5'-triphosphate (UTP) with and without pretreatment with the chloride channel blocker 4,4'-diisothiocyano-2,2'-stilbenedisulfonate (DIDS) on the transepithelial potential difference (PD), the mucus collection rate (MCR), and tracheal mucus rheology using anesthetized C57BL/6 mice. The cystic fibrosis transmembrane conductance regulator (CFTR) blocker 5-nitro-2-(3-phenylpropylamino)benzoate (NPPB) was also used as a pretreatment for MCh. After collecting baseline mucus for 1.5 h, mucus secretion was stimulated by instilling 5 microl of 10(-2) M MCh or UTP around the upper trachea. There was a significant increase in PD after MCh or UTP stimulation (-21.3+/-2.0 mV MCh versus -14.1+/-1.6 mV control; -25.4+/-2.5 mV UTP versus -19.2+/-1.9 mV control). When UTP administration was preceded by DIDS, PD shifted from -15.2+/-2.9 to -12.0+/-2.2 mV. When MCh was preceded by DIDS or by NPPB, there was no change in PD. There was a significant decrease in mucus rigidity index, logG*, with MCh (2.54+/-0.09 versus 2.99+/-0.14 for control), similar to that previously reported in other species. With UTP, 14 of 16 mice responded in terms of PD becoming more negative, and of these, there was a significant difference in logG* after UTP administration (2.29 +/-0.10 versus 2.57+/-0.10 for control), whereas there was no change in logG* with DIDS administration before UTP. When DIDS administration preceded MCh, there was a diminished but still significant decrease in logG* from control, whereas there was no change in logG* when NPPB was preadministered. The control mucus collection rate was 0.19+/-0.09 mg/h, whereas after MCh stimulation, it increased to 2.83+/-0.78 mg/h. No significant difference was measured in the MCR after either UTP or DIDS+UTP stimulation. DIDS+MCh and NPPB+MCh both resulted in significant increases in MCR, but of a much smaller magnitude than that for MCh alone. We conclude that hypersecretion owing to UTP in C57BL/6 mice is less vigorous than with MCh, reflecting the limited population of Ca(2+)-dependent Cl(-) channels stimulated by UTP P(2) receptors. The action of MCh on tracheal mucus secretion in mice appears to involve both CFTR- and non-CFTR-dependent chloride channels.     

The effect of adrenocorticotropin on histamine and 5-hydroxytryptamine secretion from rat mast cells

characteristics of histamine (Hi) and 5-hydroxytryptamine (5-HT) release from rat peritoneal mast cells in response to the polypeptide adrenocorticotropin (ACTH) were studied. During a 15 min incubation at 37°C, ACTH evoked Hias well as 5-HT release from rat mast cells at concentrations of 1×10^–4 M-1×10^–3 M. The release was dose-dependent and very rapid. After 15 sec the amount of the amines released was the same as after 4.5 min. In most experiments, the percentage of Hi release was slightly but significantly higher than the percentage of 5-HT release. Hi and 5-HT release induced by ACTH also took place in a calcium-free medium. However, the release of the amines was decreased when calcium was omitted. Comparison of the effects of ACTH, compound, 48/80 and substance P on mast cell secretion showed that ACTH is about 100 times less active then substance P which was in turn about 100 times less active than compound 48/80. When both ACTH and compound 48/80 were used together as liberators, the release was significantly higher than with either liberator alone. Our results indicate that there are receptor sites for the endogenous polypeptide ACTH on the mast cell membrane which mediate Hi and 5-HT release. This release was found to resemble, that evoked by the basic secretogogue compound 48/80 but in some aspects to be different from that evoked by substance P.     

Comparison of bronchial reactivity to histamine and methacholine in asthmatics

Eight subjects with asthma underwent bronchial challenge with histamine and methacholine. Dose-response curves were drawn on a scale which made the dosages equivalent in molecular weight. The results were analysed in terms of both the slope of the dose-response curve and the dose required to elicit a 20% fall in FEV1. No significant difference between methacholine and histamine was found in either measurement. Because of the similarity of the responses we conclude that the two agents are similar in action and may be used with equal effectiveness in bronchial challenges.     

Effect of ketotifen and oxatomide on histamine secretion from mast cells

The anti-histaminic drugs ketotifen and oxatomide have a dual effect on rat peritoneal mast cells. At high concentrations they induce histamine release, whereas at low concentrations they inhibit secretion evoked by IgE-directed ligands. The latter effect is observed in the presence and absence of exogenous calcium. The significance of this result for the general mode of action of anti-anaphylactic drugs is discussed. Neither compound liberates histamine from isolated mesenteric cells from the rat or guinea pig, further emphasizing the functional heterogeneity of mast cells from different sources.     

A comparison of methacholine and histamine inhalations in asthmatics.

Bronchial provocation tests using aerosolized serially diluted histamine and methacholine were given to nearly 200 asthmatics. Results were usually reproducible for a given patient and corticosteroids did not influence the procedures. Those patients who could tolerate high doses of methacholine were statistically the least severe asthmatics as measured by their discharge dose of corticosteroids. Reaginmediated asthmatics could not tolerate the higher doses of histamine. These tests help delineate subgroups of asthmatics and may have clinical usefulness since, when combined with other data, they differentiate pathogenetic mechanisms in some patients and suggest therapeutic approaches in others.     

The mechanism of mucus secretion by the gallbladder epithelium.

The mucus secretory granules in the chief cells of the gallbladder epithelium have been studied. The volume density of the mucus secretory granules were 0.6 +/- 0.2%, 1.5 +/- 0.4% and 1.1 +/- 0.4% in normal fasting rabbits, mice and guinea pigs respectively. Electron microscopic observations suggested that these granules were released from the epithelial cells by a mechanism analogous to a merocrine secretion.     

Nitric oxide and the cardiovascular actions of histamine

We had found that histamine (HA)-induced relaxation of cavian pulmonary artery is selectively inhibited by N^ω-methyl-l-arginine (NMA) and thus depends on the synthesis ofl-arginine (ARG)-derived EDRF/nitric oxide (NO). We have now assessed whether ARG-derived NO also mediates the coronary-vasodilating effect of HA in the intact heart. Langendorff guinea pig hearts, vasoconstricted by the thromboxane agonist U46619 (86 nM), responded to HA (bolus intra-aortic injections of 1–30 μg) with dose-dependent increases in coronary flow (20–90%), heart rate and contractility. NMA (92 μM) markedly inhibited the HA-induced increase in coronary flow, but not its positive inotropic and chronotropic effects. A similar inhibition was obtained with the NO scavenging compound, Fe²⁺-myoglobin. ARG (1 mM) reestablished the coronary-dilating effects of HA in the presence of NMA. Thus, ARG-derived NO contributes significantly to HA-induced coronary-vasodilatation. Inasmuch as the ultimate HA effect on the coronaries depends on the balance between constriction and relaxation, mediated by smooth muscle and endothelial H₁-receptors, respectively, as well as relaxation due to smooth muscle H₂-receptors, dysfunction of the NO system is likely to precipitate HA-induced vasospasm.     

Effect of calmodulin inhibitors on histamine secretion from mast cells

Histamine secretion from isolated peritoneal mast cells was inhibited by a number of calmodulin antagonists. The characteristics of the inhibition were consistent with an action after calcium influx. The rank order of potency of the compounds correlated approximately with their reported anti-calmodulin activity. These data provide tentative support for the involvement of calmodulin in stimulus-secretion coupling in the mast cell.     

Ketotifen-induced histamine release,inhibition of histamine secretion and modulation of immune response

In concentrations above 0.1 mM Ketotifen (KT) induced secretion of histamine from rat and mouse mast cells, but not from human basophils. In the same concentrations KT inhibited histamine release from rat mast cells, induced by compound 48/80 and histamine release from basophils, induced by anti-IgE-antibodies and concanavalin A. At low concen-tration (0.05–0.005 mM) KT enhancedin vitro phytohemagglutininin-induced proliferative response of human lymphocytes. The immunostimulating effect of KT was confirmedin vivo. In doses 0.18–1.4 g/mouse KT significantly increased the number of antibody-producing cells (APC) in spleens of mice immunized by sheep red blood cells (SRBC). KT stimulated both IgM- and IgG-immune response to SRBC.     

The protective effect of ipratropium bromide aerosol against bronchospasm induced by hyperventilation and the inhalation of allergen, methacholine and histamine

The ability of the anticholinergic agent, ipratropium bromide, Atrovent, (40 mcg from a metered dose inhaler) to prevent bronchoconstriction produced by four different provocation tests was compared with placebo in 12 asthmatic patients. The provocation tests used were hyperventilation and inhalations of histamine, methacholine and an allergen to which the subject was known to be sensitive. The order in which each patient received the tests was determined according to a Latin-square design and remained the same on both test days. Pretreatment with ipratropium bromide and placebo was allocated randomly and administered in double-blind fashion. Ipratropium bromide provided significant protection at the 5% level against all four types of challenge. The average number of breaths required to produce a fall of at least 20% in FEV1 (forced expiratory volume in one second) was doubled for both histamine and allergen and increased by a factor of six for methacholine. The fall in FEV1 induced by hyperventilation was approximately halved. No side effects were noted with ipratropium bromide.     

Can the epithelium affect allergen-evoked histamine release from the perfused guinea pig trachea?

The aim of this study was to investigate the influence of the epithelium on allergen-evoked histamine release. Isolated tracheal preparations from guinea-pigs, with the epithelium either left intact or removed, were used. The trachea was perfused and challenged with egg-albumin (EA) either extra- or intraluminally. Fractions of the perfusate were collected for analysis of the histamine and EA contents. When EA was added intraluminally and the epithelium was removed, a marked peak in histamine release could be detected. In the presence of intact epithelium there was no marked histamine peak. EA added extraluminally gave the same results but the histamine peak was less pronounced. The epithelium apparently acts as a barrier, the nature of which remains to be elucidated.