Effect of erythromycin on endotoxin-induced microvascular leakage in the rat trachea and lungs

To determine whether the macrolide antibiotic erythromycin prevents microvascular leakage produced by lipopolysaccharide (LPS), we studied tracheae and lungs of pathogen-free rats. Tracheal vascular permeability and neutrophil recruitment were assessed by the percent area occupied by Monastral blue-labeled blood vessels and by myeloperoxidase-containing granulocytes, respectively, in tracheal whole mounts. Pulmonary microvascular leakage was evaluated by lung wet-to-dry (W/D) weight ratio. Inhalation of Escherichia coli LPS (5 mg/kg) caused time-dependent increases in tracheal vascular permeability, neutrophil influx, and lung W/D ratio. These responses were inhibited by pretreatment with oral erythromycin, but not by ampicillin or cefaclor, in a dose-dependent manner: erythromycin at 10 mg/kg daily for 1 wk reduced the area density of Monastral blue-labeled vessels from 6.7 +/- 1.2 to 1.4 +/- 0.3% (p < 0.01), the number of neutrophils (from 365 +/- 51 to 149 +/- 30 cells/mm2, p < 0.01), and lung W/D weight ratio (from 6.76 +/- 0.30 to 5.39 +/- 0.21, p < 0.01). This inhibitory effect of erythromycin was abolished by depletion of circulating neutrophils with cyclophosphamide. These results suggest that LPS causes acute lung injury, microvascular leakage, and neutrophil recruitment in the trachea, and that erythromycin protects against these changes, probably by acting on neutrophils.

Plasma extravasation in the rat trachea induced by cold air is mediated by tachykinin release from sensory nerves

Cold air was delivered to anesthetized, artificially ventilated, pathogen-free F344 rats via a tracheal cannula. Inhalation of cold air increased Evans blue dye extravasation in the trachea in a time-dependent (1 to 10 min) manner. Plasma extravasation increased after 3 min exposure to cold air and reached a maximum after 10 min exposure. The neutral endopeptidase inhibitor, phosphoramidon (2.5 mg/kg, intravenously), increased by 84% the plasma extravasation induced by inhalation of cold air for 1 min. The plasma extravasation evoked by 5 min exposure to cold air was abolished by the NK1 tachykinin receptor antagonist, CP-99,994 (4 mg/kg, intravenously); was reduced 30% by the B2 bradykinin receptor antagonist, HOE140 (0.1 mumol/kg, intravenously); and was not affected by H1 (pyrilamine, 10 mg/kg, intraperitoneally) or H2 (cimetidine, 10 mg/kg, intraperitoneally) histamine receptor antagonists or the cyclooxygenase inhibitor indomethacin (5 mg/kg, intravenously). In rats infected with Sendai virus, plasma extravasation evoked by inhalation of cold air was greater than in pathogen-free rats. Pretreatment with CP-99,994 (4 mg/kg, intravenously) inhibited completely the plasma extravasation induced by cold air in virus-infected rats. These findings indicate that cold air increases plasma extravasation in the rat trachea by a neurogenic mechanism that involves the release of tachykinins from sensory nerves. Kinin release may also play a role in this neurogenic inflammatory response.

Synthesis and biological activity of the metabolites of syn-3-ethyl-7-methyl-3,7-diazabicyclo[3.3.1]non-9-yl 4-chlorobenzoate hydrochloride

Five metabolites of syn-3-ethyl-7-methyl-3,7-diazabicyclo[3.3.1]non-9-yl 4-chlorobenzoate hydrochloride (YUTAC) (1) were prepared and examined for Na+ current blocking activity in guinea pig ventricular myocytes. These metabolites showed lower inhibitory activities than the parent compound or were inactive.

Tachykinins and kinins in antigen-evoked plasma extravasation in guinea-pig nasal mucosa

The plasma extravasation evoked by instillation of 5% ovalbumin in the nasal mucosa of sensitized guinea-pigs was potentiated by the neutral endopeptidase inhibitor, phosphoramidon, and was reduced by the tachykinin NK1 receptor antagonist, CP-96,345. The bradykinin B2 receptor antagonist, HOE 140, also reduced the plasma extravasation evoked by the antigen. The combination of HOE 140 and CP-96,345 did not increase further the inhibition caused by HOE 140 alone. Plasma extravasation evoked by instillation of capsaicin was abolished by CP-96,345. HOE 140 blocked and CP-96,345 markedly reduced plasma extravasation caused by instillation of bradykinin. Plasma extravasation evoked by instillation of substance P was not affected by HOE 140. We conclude that antigen challenge causes plasma extravasation in the nasal mucosa of sensitized guinea-pigs, an effect that is due in part to the release of tachykinins from sensory nerve endings. Our evidence suggests that tachykinin release in response to antigen is provoked mainly by the release of kinins.

Piperazinealkanol ester derivatives of indomethacin as dual inhibitors of 5-lipoxygenase and cyclooxygenase

Piperazinealkanol ester derivatives of indomethacin were prepared and tested for inhibitory activities against 5-lipoxygenase (5-LO) and cyclooxygenase (CO). They inhibited 5-hydroxyeicosatetraenoic acid (5-HETE) formation by the cytosol of guinea pig polymorphonuclear leukocytes and thromboxane B2 (TXB2) formation by washed rabbit platelet suspension. Of the test compounds, 2-[4-(2-hydroxyethyl)-1-piperazinyl]-1-phenylethyl 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-3-indolylacetate dimaleate (II-8) was found to be the most active dual inhibitor of 5-LO and CO, and its inhibitory potency was higher than that of 2-[4-(3-hydroxypropyl)-1-piperazinyl]-ethyl [1-(4-chlorobenzoyl)-5-methoxy-2-methyl]-3-indolyacetate (CR-1015) (I), the lead compound.

Airway vasodilation by bradykinin is mediated via B2 receptors and modulated by peptidase inhibitors

We studied the effect of exogenous bradykinin on blood flow in the airway microcirculation of anesthetized F344 rats in vivo. We made three successive determinations of airway blood flow and cardiac output using a modification of the reference sample microsphere technique. Injection of bradykinin into the left ventricle increased airway blood flow in a dose-related manner. Pretreatment with the bradykinin B2 receptor antagonist, Hoe 140, completely abolished bradykinin-, but not histamine-induced vasodilation. A bradykinin B1 receptor agonist, [des-Arg9]bradykinin, did not affect airway blood flow. We also studied the effect of inhibitors of angiotensin-converting enzyme (captopril) and neutral endopeptidase (phosphoramidon) on bradykinin-induced vasodilation. Pretreatment with captopril, but not phosphoramidon, potentiated the bradykinin-induced vasodilation. However, the addition of phosphoramidon further potentiated the effect of captopril. We conclude that injection of bradykinin into the left ventricle produces a dose-related vasodilation in the airway microcirculation mediated via B2 receptors, an effect that is modulated primarily by angiotensin-converting enzyme and, to a lesser extent, by neutral endopeptidase.

Role of K+ channel opening and Na(+)-K+ ATPase activity in airway relaxation induced by salbutamol

To determine the role of K+ channel opening and Na(+)-K+ ATPase activity in the beta-adrenoceptor-mediated relaxation of airway smooth muscle, we studied canine bronchial segments under isometric conditions in vitro. Relaxant responses to salbutamol were not altered by glibenclamide or apamin but inhibited by charybdotoxin, where significant inhibition was observed only at salbutamol concentrations of less than 10(-6) M. In contrast, only the relaxations induced by salbutamol at 3 x 10(-6) M and greater were sensitive to ouabain. Relaxations produced by low and high concentrations of salbutamol were selectively attenuated by charybdotoxin and ouabain, respectively, in a concentration-dependent manner. These results suggest that both Ca(2+)-activated K+ channel and Na(+)-K+ ATPase may be operative in the airway relaxation induced by low and high concentrations of the beta-adrenergic agonist, respectively.

Interleukin-1 beta inhibits airway smooth muscle contraction via epithelium-dependent mechanism

To determine whether the cytokine interleukin (IL)-1 beta directly affects airway smooth muscle functions and, if so, what the mechanism of action is, we studied canine isolated bronchial segments under isometric conditions in vitro. Incubation of tissues with human recombinant IL-1 beta (10 ng/ml) for 150 min decreased the contractile responses to acetylcholine, histamine, and KCl. The inhibitory effect of IL-1 beta on the acetylcholine (10(-3) M)-induced contraction was concentration-dependent, the maximal decrease from the baseline contraction being 52 +/- 8% (mean +/- SD, p < 0.001) observed with 10 ng/ml IL-1 beta. Intracellular levels of cyclic AMP and cyclic GMP were not significantly altered by IL-1 beta. The IL-1 beta-induced inhibition of the contractile responses was not affected by pretreatment of tissues with indomethacin or propranolol, but it was greatly attenuated by mechanical removal of epithelium. These results suggest that IL-1 beta may play a protective role against bronchoconstrictor responses via epithelium-dependent mechanism such as the release of epithelium-derived relaxing factor.

Role of kinins in the vascular extravasation evoked by antigen and mediated by tachykinins in guinea pig trachea

Tachykinins released from sensory nerves mediate, at least in part, the plasma extravasation induced by allergen challenge to the airways of sensitized guinea pigs. We investigated the role of kinins in this activation of sensory nerves. We found that the increase in Evans blue dye extravasation evoked by aerosol of bradykinin (100 microM, 2 min) in the presence of phosphoramidon (2.5 mg/kg, i.v.) was abolished completely by the selective B2 bradykinin antagonist, HOE 140 (0.1 mumol/kg, i.v.), and was inhibited (60%) by the selective NK1 tachykinin receptor antagonist, CP-96,345 (2 mumol/kg, i.v.). Plasma extravasation evoked by aerosolized substance P (10 microM/kg, 2 min) in presence of phosphoramidon was abolished by CP-96,345, but was not affected by HOE 140. The extravasation of the Evans blue dye evoked by OVA (5%, 2 min) in sensitized guinea pigs was reduced by HOE 140 (45%) when the animals were perfused after 5 min and by 39% when perfusion was performed at 10 min. In the presence of phosphoramidon, the response to OVA at 10 min was reduced by 57% by HOE 140 and by 72% by CP-96,345. The combination of CP-96,345 and HOE 140 did not further increase the inhibition obtained with CP-96,345 alone. The results provide evidence that the activation of sensory nerves that contribute to Ag-evoked plasma extravasation is due to kinin release. The contribution of this cascade of events may be exaggerated in pathophysiologic conditions in which neutral endopeptidase is down-regulated.

Role of kinins in the vascular extravasation evoked by antigen and mediated by tachykinins in guinea pig trachea

Tachykinins released from sensory nerves mediate, at least in part, the plasma extravasation induced by allergen challenge to the airways of sensitized guinea pigs. We investigated the role of kinins in this activation of sensory nerves. We found that the increase in Evans blue dye extravasation evoked by aerosol of bradykinin (100 microM, 2 min) in the presence of phosphoramidon (2.5 mg/kg, i.v.) was abolished completely by the selective B2 bradykinin antagonist, HOE 140 (0.1 mumol/kg, i.v.), and was inhibited (60%) by the selective NK1 tachykinin receptor antagonist, CP-96,345 (2 mumol/kg, i.v.). Plasma extravasation evoked by aerosolized substance P (10 microM/kg, 2 min) in presence of phosphoramidon was abolished by CP-96,345, but was not affected by HOE 140. The extravasation of the Evans blue dye evoked by OVA (5%, 2 min) in sensitized guinea pigs was reduced by HOE 140 (45%) when the animals were perfused after 5 min and by 39% when perfusion was performed at 10 min. In the presence of phosphoramidon, the response to OVA at 10 min was reduced by 57% by HOE 140 and by 72% by CP-96,345. The combination of CP-96,345 and HOE 140 did not further increase the inhibition obtained with CP-96,345 alone. The results provide evidence that the activation of sensory nerves that contribute to Ag-evoked plasma extravasation is due to kinin release. The contribution of this cascade of events may be exaggerated in pathophysiologic conditions in which neutral endopeptidase is down-regulated.

Levodropropizine reduces capsaicin- and substance P-induced plasma extravasation in the rat trachea

We investigated the effect of the non-opioid, peripherally acting antitussive agent levodropropizine to reduce neurogenic plasma extravasation in the rat trachea. Levodropropizine (10, 50 and 200 mg/kg) reduced in a dose-dependent manner the extravasation of Evans blue dye evoked by capsaicin. Levodropropizine inhibited also substance P-evoked extravasation, whereas it did not affect the extravasation evoked by platelet activating factor. Levodropropizine (10 and 100 microM) did not affect the contraction produced by [Sar9,Met(O2)11]substance P, a selective agonist for tachykinin NK1 receptors, in the rat urinary bladder in vitro. These data indicate that levodropropizine inhibits capsaicin-induced plasma extravasation: (a) acting at a postjunctional level; (b) exhibiting neuropeptide selectivity and; (c) via a mechanism independent of tachykinin NK1 receptor blockade. Irrespective of the mechanism, this novel antiinflammatory action of levodropropizine underlines its potential role in inflammatory airway diseases such as bronchial asthma.

Effect of somatostatin on contractile and relaxant responses of tracheal smooth muscle in rabbits

To determine the effect of somatostatin (SRIF) on airway smooth muscle contractile and relaxant responses and its mechanism of action, we studied rabbit tracheal smooth muscle under isometric conditions in vitro. SRIF did not change the contractile responses to electrical field stimulation and acetylcholine, but it inhibited the relaxant responses to isoproterenol in a concentration-dependent manner, an effect that was reversed by treatment of tissues with pertussis toxin (PTX). In contrast, the forskolin- and verapamil-induced relaxations were not altered by SRIF. SRIF also attenuated the increase in intracellular cyclic AMP levels in response to isoproterenol. These results suggest that SRIF may decrease beta-adrenoceptor-mediated muscle relaxation by acting at the site proximal to cyclic AMP synthesis, especially at PTX-sensitive GTP-binding regulatory protein, Gi, coupled to adenylate cyclase.

Ruthenium red, but not capsazepine reduces plasma extravasation by cigarette smoke in rat airways

1. Cigarette smoke increases vascular permeability in rat airways by activating release of tachykinin from capsaicin-sensitive sensory nerves. However, the mechanism by which cigarette smoke induces secretion of sensory neuropeptides is unknown. Here we hypothesized that cigarette smoke activates sensory nerve endings via a mechanism similar to that of capsaicin. 2. We studied the effects of ruthenium red, an inorganic dye which blocks the cation influx promoted by capsaicin and of the capsaicin antagonist capsazepine on the increase in vascular permeability produced by cigarette smoke, capsaicin, hypertonic saline and substance P in the trachea of pentobarbitone anaesthetized rats. We also investigated the ability of cigarette smoke to desensitize sensory nerve fibres. 3. Ruthenium red (10 mM) by aerosol blocked the increase in vascular permeability induced by capsaicin (0.5 microM) and reduced the response to cigarette smoke (5 puffs) but did not affect responses evoked by hypertonic saline (7.2%) or by substance P (10 microM) (all given by aerosol). Aerosols of capsazepine (0.1 mM) prevented extravasation by capsaicin, but did not inhibit response to cigarette smoke, hypertonic saline or substance P. Finally, pre-exposure to a high dose of cigarette smoke (10 puffs) prevented the extravasation caused by cigarette smoke (5 puffs) itself and by intravenous capsaicin (150 micrograms kg-1), but not that by intravenous substance P (10 nmol kg-1). 4. The present results show that cigarette smoke: (a) increases vascular permeability in the rat airways by a mechanism that is not antagonized by capsazepine, and is partially sensitive to rutheniun red; (b)produces desensitization of capsaicin-sensitive sensory nerves. We propose that chemical(s) contained in or agent(s) produced by cigarette smoke in the airways share partially a common pathway with capsaicin to activate peptide release from capsaicin-sensitive sensory nerves, but do not bind to the putative 'capsaicin receptor'.

Role of neurogenic inflammation in antigen-induced vascular extravasation in guinea pig trachea

Conflicting results have been reported about the role of sensory nerves in the allergen-induced plasma extravasation in sensitized guinea pigs using capsaicin desensitization. To investigate the role of tachykinins released from sensory nerves in the anaphylactic reaction in guinea pigs in vivo, we used a selective inhibitor of neutral endopeptidase, phosphoramidon, and a selective neurokinin (NK)-1 receptor antagonist, CP-96,345. Male Hartley guinea pigs were sensitized to OVA by two i.p. injections (70 mg) at 1-wk intervals. Two wk later, the animals were anesthetized and OVA was administered for 2 min by aerosol through a tracheal cannula. Plasma extravasation was assessed by the photometric measurement of the extravasated Evans blue after formamide extraction. Administration of aerosolized OVA to sensitized guinea pigs increased dye extravasation in the trachea in a dose-dependent manner, an effect that was demonstrable 5 min after exposure to allergen and that reached a maximum 10 min after exposure. At 5 min after OVA (5%), phosphoramidon (2.5 mg/kg, i.v.) did not increase the amount of dye in the trachea significantly and CP-96,345 (4 mg/kg) did not decrease the extravasated dye. At 10 min after OVA, allergen-induced plasma extravasation was potentiated by phosphoramidon by 56%, and was inhibited by CP-96,345 (4 mg/kg) by 42%. In the presence of phosphoramidon, CP-96,345 reduced the OVA-evoked plasma extravasation at 10 min in a dose-related manner (0.1-4 mg/kg). CP-96,345 (4 mg/kg) did not affect plasma extravasation induced by platelet-activating factor (100 nmol/kg, i.v.). These results suggest that tachykinin release from sensory nerves after allergen challenge to airways in sensitized guinea pigs is not responsible for the early increase in plasma extravasation, but, tachykinin release appears to play an important role in the subsequent extravasation.

Role of neurogenic inflammation in antigen-induced vascular extravasation in guinea pig trachea

Conflicting results have been reported about the role of sensory nerves in the allergen-induced plasma extravasation in sensitized guinea pigs using capsaicin desensitization. To investigate the role of tachykinins released from sensory nerves in the anaphylactic reaction in guinea pigs in vivo, we used a selective inhibitor of neutral endopeptidase, phosphoramidon, and a selective neurokinin (NK)-1 receptor antagonist, CP-96,345. Male Hartley guinea pigs were sensitized to OVA by two i.p. injections (70 mg) at 1-wk intervals. Two wk later, the animals were anesthetized and OVA was administered for 2 min by aerosol through a tracheal cannula. Plasma extravasation was assessed by the photometric measurement of the extravasated Evans blue after formamide extraction. Administration of aerosolized OVA to sensitized guinea pigs increased dye extravasation in the trachea in a dose-dependent manner, an effect that was demonstrable 5 min after exposure to allergen and that reached a maximum 10 min after exposure. At 5 min after OVA (5%), phosphoramidon (2.5 mg/kg, i.v.) did not increase the amount of dye in the trachea significantly and CP-96,345 (4 mg/kg) did not decrease the extravasated dye. At 10 min after OVA, allergen-induced plasma extravasation was potentiated by phosphoramidon by 56%, and was inhibited by CP-96,345 (4 mg/kg) by 42%. In the presence of phosphoramidon, CP-96,345 reduced the OVA-evoked plasma extravasation at 10 min in a dose-related manner (0.1-4 mg/kg). CP-96,345 (4 mg/kg) did not affect plasma extravasation induced by platelet-activating factor (100 nmol/kg, i.v.). These results suggest that tachykinin release from sensory nerves after allergen challenge to airways in sensitized guinea pigs is not responsible for the early increase in plasma extravasation, but, tachykinin release appears to play an important role in the subsequent extravasation.

Atypical beta-adrenoceptor- (beta 3-adrenoceptor) mediated relaxation of canine isolated bronchial smooth muscle

To determine whether atypical beta-adrenoceptors (beta 3-adrenoceptors) exist in the airway smooth muscle, we studied isolated bronchial segments from dogs under isometric conditions in vitro. Addition of beta-adrenoceptor agonists produced a concentration-dependent relaxation of tissues precontracted with 10(-5) M acetylcholine, rank-order potency being isoproterenol (1) > or = salbutamol (0.95) > or = BRL 37344, a beta 3-selective adrenoceptor agonist (0.83) > norepinephrine (0.10). Under the condition that alpha- and beta 1-adrenoceptors had been blocked, the relaxant response to salbutamol was competitively antagonized by the beta 2-adrenoceptor antagonist ICI 118551 and the pA2 was 7.01 +/- 0.25 (SE), whereas the response to BRL 37344 was resistant, with an apparent pA2 of 5.66. However, cyanopindolol, an antagonist for atypical beta-adrenoceptors, antagonized the BRL-induced relaxation in a competitive manner, with a pA2 of 6.74 +/- 0.11. This pA2 was lower than that when salbutamol was used as an agonist (P < 0.05). Intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels were increased by BRL 37344 in a concentration-dependent fashion. These results suggest that beta 3-adrenoceptors may exist in canine bronchial smooth muscle and that the stimulation of this type of receptor causes a bronchodilation through a cAMP-dependent pathway.

Angiotensin II potentiates neurally mediated contraction of rabbit airway smooth muscle

The effect of angiotensin II (AT II) on cholinergic neurotransmission in rabbit tracheal segments was studied under isometric conditions in vitro. AT II concentration-dependently potentiated the contractile response to electrical field stimulation (EFS), and caused a leftward shift of the frequency-response curves for EFS, so that the stimulus frequency required to produce a half-maximal effect (ES50), decreased from 7.0 +/- 0.1 to 3.0 +/- 0.1 Hz (P less than 0.01). In contrast, the contractile response to acetylcholine was not affected. Non-peptide AT II receptor antagonist CV-2961 attenuated the effect of AT II on the EFS-induced contraction. Pretreatment of tissues with thiorphan or phosphoramidon did not alter the action of AT II. Thus, AT II may prejunctionally potentiate the neurally-mediated contraction of airway smooth muscle through activation of AT II receptors on the cholinergic nerve terminals, and this effect may not be modulated by endogenous neutral endopeptidase.

Non-opioid-dependent inhibitory action of loperamide on cholinergic neurotransmission in canine isolated bronchial smooth muscle

The effect of loperamide on cholinergic neurotransmission in canine bronchial smooth muscle was studied under isometric conditions in-vitro. Addition of loperamide decreased contractile responses to electrical field stimulation in a dose-dependent fashion, the maximal decrease from the control response and the IC50 value being 65.4 +/- 5.9% and 1.5 microM, respectively. In contrast, loperamide was without effect on the responses to exogenously administered acetylcholine. The inhibitory effect of loperamide was not altered by pre-incubation of tissues with propanol, 6-hydroxydopamine, bicuculline, or naloxone. These results suggest that loperamide attenuates the neurally mediated airway contraction probably by inhibiting acetylcholine release from cholinergic nerve terminals through a non-opioid-dependent mechanism.

Alveolar attachments in emphysema of human lungs

We have studied alveolar attachments to membranous bronchioles in 41 patients enrolled in the National Institutes of Health Intermittent Positive Pressure Breathing Trial who died, came to autopsy, and provided adequate tissue for examination. The patients had moderate to severe chronic airflow obstruction and, on the average, severe emphysema. We measured the number of normal attachments per membranous bronchiole per case (N), the number of normal attachments per mm of circumference per bronchiole per case (Nunit), and the ratio of abnormal to all attachments (R). All measurements correlated closely to all measurements of emphysema and to irregular shape of bronchioles (deformity index). Measurement of abnormal attachments correlated with abnormal tests of pulmonary function, including evidence of airflow obstruction and diffusing capacity for carbon monoxide (DLCO). Nunit showed the most frequent correlations, but both N and Nunit were only related independently of emphysema for Phase III of the single-breath nitrogen test. R was related to loss of DLCO. We conclude that loss of attachments is not itself a cause of airflow obstruction but rather a correlate of emphysema, which is the proximate cause of the obstruction. Loss of alveolar attachments has an effect only on the single-breath nitrogen tests independent of emphysema.

Effects of platelet-activating factor on bioelectric properties of cultured tracheal and bronchial epithelia

To elucidate the effect of platelet-activating factor (PAF) on ion transport function of airway epithelial cells, we studied bioelectric properties of cultured tracheal and bronchial epithelia from dogs under short-circuit conditions in vitro. Addition of PAF (10(-5) mol/L) to mucosal solution of Ussing chamber increased short-circuit current of tracheal epithelium from 3.3 +/- 0.7 to 8.5 +/- 1.2 microA/cm2 (p less than 0.001). This effect was dose dependent, and there was a corresponding increase in transepithelial potential difference. In contrast, PAF was without effect when it was added to the submucosal side. Electrical properties of bronchial epithelium remained unchanged by PAF. The PAF-induced increase in short-circuit current was not affected by amiloride but abolished by diphenylamine-2-carboxylate, bumetanide, or Cl-free medium. The effects of PAF were not altered by AA-861 or U-60257, but attenuated by indomethacin and piroxicam, and dose-dependently blocked by CV 6209 and WEB 2086. Mucosal, but not submucosal, addition of PAF increased the rate of prostaglandin release from tracheal epithelium. These results suggest that PAF selectively stimulates Cl secretion across tracheal epithelium, probably through activation of its specific receptors and the subsequent production of prostaglandins.

IgE-dependent activation of alveolar macrophages augments neurally mediated contraction of small airways

1. We studied the effect of immunologically activated pulmonary alveolar macrophages (PAM) on functions of canine bronchiolar smooth muscle under isometric conditions in vitro. 2. PAM, stimulated with monoclonal anti-dinitrophenyl (DNP) IgE antibody and DNP-human serum albumin (DNP-HSA), augmented the contractile responses of bronchioles to electrical field stimulation, whereas PAM treated with IgE antibody alone had no effect. 3. In contrast, the contractile responses to exogenously administered acetylcholine were not influenced by immunologically activated PAM. 4. The PAM-induced increase in the contractile responses to field stimulation was inhibited by pretreatment of PAM with indomethacin and by addition of the thromboxane A2 (TxA2) receptor antagonist SQ 29548. 5. The release of TxA2 from PAM was increased by anti-DNP IgE and DNP-HSA, an effect that was prevented by indomethacin. 6. These results suggest that PAM may play a role in the development of antigen-induced hyperreactivity of small airways through an IgE-dependent release of TxA2 which potentiates prejunctionally the parasympathetic component of bronchiolar smooth muscle tone.

Synthesis and antiestrogenic activity of the compounds related to the metabolites of (E)-4-[1-[4-[2-(dimethylamino)ethoxy]phenyl]- 2-(4-isopropylphenyl)-1-butenyl]phenyl monophosphate (TAT-59) [corrected]

The metabolites of (E) [corrected]-4-[1-[4-[2-dimethylamino)ethoxy]phenyl]- 2-(4-isopropylphenyl)-1-butenyl]phenyl monophosphate, TAT-59, (1), a potent antitumor agent for hormone-dependent tumors, and derivatives of TAT-59 were synthesized to confirm its proposed structure. The structure and the Z-configuration of the metabolites (2a-8a) were confirmed by comparison with synthesized authentic compounds. All of the metabolites and the derivatives of TAT-59 were tested for a binding affinity toward estrogenic receptors in vitro and antiuterotrophic activity in vivo. Most of the metabolites possessed remarkable binding affinity toward estrogenic receptors as well as fairly good antiuterotrophic activity.