Phase II trial of 10-deazaaminopterin for advanced hypernephroma

10-Deazaaminopterin, a derivative of aminopterin with enhanced cellular uptake relative to methotrexate, was given to fourteen patients with advanced measurable hypernephroma. The dose-limiting toxicity was mucositis. Abnormalities in liver function were seen in 8 patients. No responses were seen in 13 adequately treated patients including 10 who had received no prior chemotherapy. The unique transport of this new group of compounds is discussed.

Sequential trials of methotrexate, cisplatin and bleomycin for penile cancer

Methotrexate, bleomycin or cisplatin was used to treat 21 patients with advanced bidimensionally measurable epidermoid carcinoma of the penis. Patient characteristics were similar in all 3 drug trials. Drug therapy was continued with each agent until the disease progressed. Significant tumor regression was observed in 8 of 13 men (61 per cent) treated with methotrexate, 3 of 12 (25 per cent) treated with cisplatin and 3 of 14 (21 per cent) treated with bleomycin. Responders tended to be younger than nonresponders (median age 48 versus 59 years, respectively, p less than 0.05) and lived a median of 8 versus 2 months, respectively (p equals 0.03). Cross-resistance was not encountered among the 3 drugs. Future trials might investigate combination regimens of all 3 agents.

Estrogen, progesterone, and androgen-binding sites in renal cell carcinoma. Observations obtained in Phase II trial of flutamide

A Phase II disease-oriented drug trial using flutamide (4'-nitro-3'trifluoro-methylisobutyranilide) 250 mg by mouth three times a day was undertaken in 28 patients with advanced, bidimensionally measurable renal cell carcinoma. Of 25 adequately treated cases, 1 (4%, 95% confidence limits 0-12%) had a partial remission lasting 9+ months, and 2 had stabilization of disease lasting 6 and 15 months, respectively. Flutamide demonstrated no significant antitumor activity in patients with disseminated renal cell carcinoma. Including patients entered in this study, 62 specimens were evaluated for steroid binding sites using a fluorescent method: 33 of 62 specimens assayed showed no hormone-binding sites, and only 12 cases had androgen binding. Of the 12 of 23 patients receiving flutamide who were biopsied and had an adequate sample for steroid-binding site determination, estrogen binding was demonstrated in 6, androgen binding in 3, and progesterone binding in 4. Since this study did not obtain a sufficient number of cases with androgen-binding positivity, the possible efficacy of flutamide in such cases cannot be excluded.

Genetic variation for West Nile virus susceptibility in Culex tritaeniorhynchus

Mutant and geographical strains of Culex tritaeniorhynchus were compared for West Nile (WN) virus susceptibility by feeding on a high-titered blood-virus suspension. Eleven strains also were selected from 2-21 generations for an increase and/or a reduction of oral susceptibility using 90% and 10% infective virus doses, respectively. Only one of the 20 strains tested, e ma, was significantly less susceptible than the control strain. In the selection experiments, none of the strains showed a consistent decrease in susceptibility, but the Changa Manga II (CM) strain showed a sustained increase in susceptibility from generations F11-F21 when selection was discontinued. Reciprocal cross-matings and back-crosses were set up between the selected CM strain and two of the morphological mutant strains, e ma and re e ae, carrying homozygous recessive markers. The resulting progeny were tested for susceptibility to WN virus infection and the ability to replicate virus to high-titers after infection. These results suggest that the trait of increased susceptibility is dominant over resistance. The enhanced ability of infected mosquitoes to replicate WN virus showed partial dominance. Both of these traits appear to be polyfactorial, and are apparently associated with more than one chromosome in Cx. tritaeniorhynchus.

An appraisal of the efficacy of bleomycin in epidermoid carcinoma of the penis

Since 1975 ten patients with advanced bidimensionally measurable epidermoid carcinoma of the penis were treated prospectively with bleomycin as a single agent. In addition, data of four patients with penile cancer treated at Memorial Hospital in 1971-72 as part of a drug-oriented prospective Phase I-II trial of bleomycin are included. Each patient had a complete evaluation including measurement of all measurable lesions by two independent observers. Standard response criteria were used. Bleomycin was given in doses of 3-20 mg/m2/day in a continuous infusion to 8 men and as a daily or weekly bolus in doses of 10-30 mg/m2 to six men. The median age of the patients was 54 years and median KPS 50%. Six patients had previously received two or more chemotherapeutic agents. All patients had Stage III-IV disease. Three (21%) of 14 patients responded including one patient who achieved a complete remission in the primary penile lesion and in malignant inguinal lymphadenopathy. Tumor regression was noted to start rapidly, i.e. within 2 weeks of starting protocol, but the duration of remission was short - median 3 months. The most frequent toxicity was mucositis which occurred in 8 cases. Three patients had a drug-related fever, two a drug rash and 2 had evidence of pulmonary toxicity. There was one instance each of an elevation of tests of liver function, and of alopecia. Within the context of this study, bleomycin has modest activity and moderately severe toxicity in patients with advanced penile carcinoma.

Inhibition of antigen-induced bronchoconstriction by methylprednisolone succinate

We investigated whether the glucocorticoid methylprednisolone succinate mg/kg) could prevent antigen-induced bronchoconstriction in conscious sheep. Ten allergic ewes were subjected to inhalation challenge with Ascaris suum antigen, with and without methylprednisolone pretreatment, administered intravenously either 20 min or 3 hr before antigen challenge. Antigen challenge alone resulted in increased airflow resistance, pulmonary hyperinflation, and decreases in dynamic lung compliance and arterial oxygen tension. Methylprednisolone administered 20 min before antigen challenge had no effect on these antigen-induced changes. In contrast, administration of methylprednisolone 3 hr before antigen challenge effectively prevented all the responses to antigen challenge. We suggest that pretreatment with glucocorticoids can attenuate airway anaphylaxis if sufficient time is allowed between the pretreatment and the antigen challenge.

Activity of sequential low-dose methotrexate and fluorouracil in advanced colorectal carcinoma: attempt at correlation with tissue and blood levels of phosphoribosylpyrophosphate

Forty-five patients with metastatic colorectal carcinoma were treated with low-dose methotrexate (MTX) and 5-fluorouracil (5-FU) given sequentially. The dose of MTX was 40 mg/m2 intravenously (IV) on days 1 and 8 followed 24 hours later by 5-FU at 600 mg/m2 IV on days 2 and 9; the drugs were recycled every 28 days. Fourteen (32%) of 43 adequately treated patients had a complete or partial response lasting a median of nine months (range, 6-15 + months). Four patients had a minor response and seven patients had stable disease for a median of nine and 10 months, respectively. Toxicity included mucositis in 28 (65%) patients, diarrhea in 18 (40%), nausea in 11 (24%), and vomiting in seven (16%). Hematologic toxicity was mild: six patients had nadir white blood cell counts less than 3.5 X 10(3) cells/microL, and seven patients had a nadir platelet count less than 100 X 10(3) cells/microL. Serial biopsies and blood samples were obtained in selected patients to evaluate the effect of MTX on tissue and lymphocyte phosphoribosylpyrophosphate (PRPP) and PRPP synthetase levels.

Similar specificity of membrane transport for folate analogues and their metabolites by murine and human tumor cells: a clinically directed laboratory study

Mediated transport of folate compounds exhibited similar kinetic characteristics and structural specificity in a series of cultured murine and human tumor cells examined in a parallel fashion. In each case, influx was characterized by a single saturable component with an approach to steady-state conforming to a single exponential, while efflux was first order (poorly saturable). Both mediated fluxes exhibited high temperature dependence (Q10 27-37 degrees = 6 to 8). During competition studies with various analogues, it was found that positions 4, 5, 7, and 10 and the gamma-carboxyl position of the folate molecule were specified for influx in tumor cells from each species. Also, short-chain alkyl substitution at position 10 was specified in the case of N10, but not in the case of C10. None of the modifications at position 10 affected mediated efflux in either cell type. The linkage of additional glutamyl residues at the gamma-carboxyl-position resulted in reduced saturability (increased value for Ki) of influx in both murine and human tumor cells in a manner proportional to the number of glutamyl residues. Mediated influx in human ovarian carcinoma cells obtained from malignant effusions in several patients and in an established cell line derived from one of these patients showed similar kinetics for folate analogue transport and specificity for modification at position 10 of the 4-amino-folate molecule. Mediated entry of 10-deazaaminopterin and its 10-ethyl derivative compared to entry of methotrexate was 4- to 11-fold greater in murine tumor cells and 4- to 9-fold greater in human tumor cells in culture or when clinically derived. Mediated efflux was not specified for position 10 on the 4-amino folate structure in any tumor cell type. These findings appear to provide some basis for concluding that the results of studies of this type in model murine systems or with tumor cell lines established in culture have relevance to clinical cancer.

Effect of positive end-expiratory pressure on breathing patterns of normal subjects and intubated patients with respiratory failure

The aims of this study included assessment of accuracy of respiratory inductive plethysmography when pulmonary hyperinflation was induced by application of PEEP, and examination of breathing patterns of normal subjects, intubated patients requiring mechanical ventilation and intubated patients immediately before extubation during application of PEEP by demand valve and high gas flow reservoir bag systems. Validation of tidal volume (VT) and end-expiratory level measured with respiratory inductive plethysmography to simultaneous spirometry (SP) was achieved with PEEP levels up to 12.5 cm H2O in 7 normals. In 17 intubated patients, almost all VT values measured with respiratory inductive plethysmography fell within +/- 10% of SP even with 2 to 3 changes of body posture. In normal subjects, increasing levels of PEEP from the demand valve system produced nonprogressive rises of VT and mean inspiratory flow, falls of frequency and fractional inspiratory time (TI/TTOT), and no changes of minute ventilation (Vmin) nor mean expiratory flow. PEEP from the high gas flow reservoir bag system produced nonprogressive rises of VT and rib cage (RC) contribution to VT, and rises of Vmin and mean inspiratory and expiratory flows between 10.0 and 12.5 cm H2O of PEEP. Intubated patients requiring intermittent mandatory ventilation (IMV) had a rapid, shallow breathing pattern unaltered by PEEP levels delivered by either system up to 12.5 cm H2O despite increases of end-expiratory level. Intubated patients who were about to be extubated breathed with patterns closer to ambulatory normal subjects with the exception of their elevated RC contribution to VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Phase II trial of 4'epi-adriamycin for advanced hypernephroma

4'Epi-adriamycin in doses of 85-110 mg/m2 I.V. Q3W was given to 20 patients with advanced bidimensionally measurable hypernephroma. Forty-five doses were administered, with 10 patients receiving 3-7 doses. Myelosuppression (WBC nadir 2600 cells/mm3, range 1000-3400) occurred in 63% and thrombocytopenia in 16% of cases. There was no objective response in 19 adequately treated cases.

Functional depression of H2 histamine receptors in sheep with experimental allergic asthma

We tested the hypothesis that airway hyperresponsiveness to histamine in the allergic sheep is related to functional depression of H2 histamine receptors. Thirteen of 32 sheep responded with bronchoconstriction to inhaled Ascaris suum antigen (allergic sheep), and the remainder served as controls (nonallergic sheep). In the allergic sheep, 50 and 100 breaths of 5% histamine solution increased mean pulmonary resistance (RL) to 235% and 438% of baselines, respectively. The corresponding values in nonallergic sheep were 200% and 211%, indicating a greater response to the higher dose of histamine in allergic sheep. Selective H1-receptor stimulation with 50 breaths of histamine (pretreatment with the H2-receptor antagonist metiamide) failed to enhance the effect of histamine in allergic sheep (mean RL increased to 239% of baseline) whereas it enhanced the histamine response in nonallergic sheep (RL increased to 438% of baseline). Selective H2-receptor stimulation (pretreatment with the H1-receptor antagonist chlorpheniramine) caused histamine to decrease RL by 31% in the nonallergic sheep group; it blocked but did not reverse the histamine effect in the allergic sheep. Similar observations were made in a different group of animals when selective H1- or selective H2-receptor stimulation was produced by 100 breaths of histamine. The cutaneous wheal response to intradermal histamine dilutions of 0.0001. 0.001, 0.01, and 1 mg/ml was similar in both groups. In nonallergic sheep, both chlorpheniramine and metiamide blunted the cutaneous wheal response. In allergic animals, only chlorpheniramine blunted the cutaneous wheal response, whereas metiamide was without effect. We conclude that airway hyperresponsiveness to histamine in allergic sheep is related to a functional depression of H2 receptors and that such a defect is observed both in the airways as well as in the skin.

Modification of allergic bronchoconstriction by a calcium antagonist: mode of action

Because both degranulation of mast cells and contraction of airway smooth muscle are dependent upon the influx of calcium, a calcium blocking agent might modify allergic bronchoconstriction by at least these two mechanisms. We treated sheep allergic to Ascaris suum antigen with the calcium antagonist Verapamil prior to airway challenge with an aerosol of Ascaris suum antigen and also investigated the response without pretreatment. Aerosolized Ascaris suum antigen increased mean pulmonary resistance (RL) to 530% of baseline (n = 6). Pretreatment with intravenously administered Verapamil (150 micrograms/kg) increased mean RL to 225% of baseline but bronchoconstriction produced by subsequent antigen challenge was completely prevented. Verapamil did not modify bronchoconstriction produced by aerosols of histamine and carbachol, agents that act upon airway smooth muscle. Further, it did not reverse the increase in RL induced by an intravenous infusion of carbachol. These results suggest that verapamil, at the dosage used, did not prevent allergic bronchoconstriction by a direct action on smooth muscle and therefore was effective by inhibiting the release of mast cell mediators.

Does slow-reacting substance of anaphylaxis mediate hypoxic pulmonary vasoconstriction?

We have previously established a relationship between mast cell degranulation and hypoxic pulmonary vasoconstriction (HPV). In the present study, we investigated the possible role of slow-reacting substance of anaphylaxis (SRS-A) in the mediation of HPV. In 18 conscious sheep, pulmonary artery pressure, pulmonary arterial wedge pressure, and cardiac output were measured for the calculation of pulmonary vascular resistance (PVR) along with arterial oxygen tension (PaO2) while breathing room air and while breathing 13% O2 (balance, N2). Before and during 13% O2 breathing (pretreatment), Group 1 received an intravenous infusion of cromolyn sodium (3 mg/kg-1/min-1) and Group 2 was infused with FPL-57231, a SRS-A antagonist (2 mg/kg-1/min-1); Groups 3 and 4 received infusions of cromolyn sodium or FPL-57231 after induction of HPV. During 13% O2 breathing (mean PaO2, 47 mmHg), mean PVR increased to 190% of baseline. Pretreatment with cromolyn sodium prevented HPV, whereas infusion of cromolyn sodium after induction of HPV failed to reverse it; FPL-57231 both prevented HPV (pretreatment) and reversed it when infused after induction of HPV. Pretreatment with the prostaglandin synthetase inhibitor indomethacin (2 mg/kg) 1 h before the experiment failed to modify the FPL-57231-induced reversal of hypoxic vasoconstriction, thus excluding the release of inhibitory prostaglandins by this compound. We conclude that cromolyn sodium prevented HPV, presumably by inhibiting the release of SRS-A, which mediates pulmonary vasoconstriction directly or indirectly through other mechanisms.

Modification of airway histamine-receptor function with methylprednisolone succinate

The purpose of the present study was to investigate whether glucocorticosteroids alter airway histamine-receptor function. We measured pulmonary resistance in six conscious sheep before and after inhalation challenge with 100 breaths of 5% histamine solution, without and with intravenous pretreatment with the specific H1- and H2-receptor antagonists. Inhalation of histamine (combined H1 and H2 stimulation) increased mean pulmonary resistance (RL) to 290% of baseline (p less than 0.05). Pretreatment with the H2 antagonist, metiamide (selective H1 stimulation), enhanced the effect of histamine, with a mean RL increase to 760% of baseline (p less than 0.05). Histamine challenge after pretreatment with the H1 antagonist, chlorpheniramine (selective H2 stimulation), decreased RL to 40% of chlorpheniramine value (p less than 0.05). A single intravenous bolus injection of methylprednisolone succinate (30 mg/kg) 30 min before histamine challenge suppressed the airway responsiveness to histamine, with a mean RL increase to only 186% of baseline. After methylprednisolone, selective H1-receptor stimulation with histamine elicited a blunted H1-receptor response; mean RL increased to only 248% of baseline. Both changes were significantly lower than that with histamine alone (p less than 0.05). Methylprednisolone per se blunted the chlorpheniramine-induced increase in RL which made it difficult to evaluate H2-receptor function (RL decreased to 67% of postchlorpheniramine value). However, in the presence of increased airway tone with carbachol, selective H2 stimulation with histamine decreased RL to 26% of postcarbachol value (p less than 0.05), thus excluding suppression of H2 receptors. Methylprednisolone had no effect on carbachol-induced increase in RL. In conscious sheep, methylprednisolone blunts airway responsiveness to histamine by suppressing H1 receptors without significantly altering H2 receptors or cholinergic-receptor function.

Histamine receptor blocking effects of cimetidine in the airways

We investigated the modification of histamine-induced bronchoconstriction by the H2-antagonist cimetidine in conscious sheep. One hundred breaths of 5% histamine aerosol increased mean (SD) pulmonary resistance (RL) by 5.6 (1.4) cmH2O/l/sec. This increase in RL was completely blocked by intravenous clemastine (0.5 mg), a specific H1-antagonist, indicating that the histamine-induced bronchoconstriction was mediated by H1-receptors. Intravenous cimetidine caused a dose-dependent enhancement of the histamine response between 1 and 1000 mg with a mean peak delta RL of 15.3 (5) cmH2O/l/sec (p less than 0.05) at the 1000 mg dose, while it blocked the histamine response at a dose of 2400 mg [delta RL = 1.9 (2) cmH2O/l/sec, p = NS]. This paradoxic effect was not related to an anticholinergic mechanism as intravenous cimetidine (2400 mg) failed to block carbachol-induced (25 breaths of 1% solution) bronchoconstriction. We conclude that in the ovine airway, cimetidine is a selective H2-histamine receptor blocker at lower tissue concentrations, and a combined H2- and H1-histamine receptor blocker at high tissue concentrations.

Variability of hypoxic pulmonary vasoconstriction in sheep. Role of prostaglandins

In a minority of conscious sheep, the hypoxic pulmonary vasoconstrictor response is blunted ("nonresponders"). The purpose of this investigation was to determine if this blunted response is related to an increased activity of H2-histamine receptors, beta-adrenergic receptors, or the generation of inhibitory prostaglandins. We measured pulmonary arterial pressure, pulmonary arterial wedge pressure, and pulmonary blood flow for the calculation of pulmonary vascular resistance (PVR) in 5 "nonresponders" and 5 sheep with a typical hypoxic pulmonary vasoconstrictor response ("responders") while breathing room air and 13% O2 (balance, N2). Arterial oxygen tension (PaO2) was also determined as a measure of the severity of hypoxia. During hypoxia, mean PVR increased by 6% (p = NS) in the "nonresponders" (PaO2, 49 +/- 4 mmHg), and by 70% (p less than 0.01) in the "responders" (mean PaO2, 46 +/- 4 mmHg). Metiamide (H2-blocker) and propranolol (beta-adrenergic blocker) pretreatments did not restore the hypoxic pulmonary vascular response in the "nonresponders," whereas pretreatment with indomethacin (prostaglandin synthetase inhibitor) caused mean PVR to increase by 48% (p less than 0.01) during hypoxia, indicating a partial restoration of hypoxic pulmonary vasoconstriction. In the "responders," the hypoxic pulmonary vascular response was not potentiated by indomethacin pretreatment (68% increase in mean PVR). We conclude that some sheep exhibit a blunted hypoxic pulmonary vasoconstrictor response caused by enhanced production of inhibitory prostaglandins.

Hypoxic pulmonary vasoconstriction in conscious sheep: role of mast cell degranulation

We used pharmacologic and histologic techniques to investigate the role of mast cells in the mediation of hypoxic pulmonary vasoconstriction in conscious sheep. Breathing a hypoxic gas mixture (13%, 02, 87% nitrogen) caused hypoxic pulmonary vasoconstriction (HPV) with increases in mean pulmonary artery pressure and pulmonary vascular resistance by 97 and 90%, respectively. Intravenous pretreatment with the mast cell membrane stabilizing agent cromolyn sodium (3 mg/kg/min) completely blocked HPV, whereas the H1-histamine receptor antagonist chlorpheniramine, alone or in combination with the H2-receptor antagonist metiamide and the prostaglandin synthetase inhibitor indomethacin, failed to prevent HPV. Cromolyn sodium failed to modify the pulmonary pressor response to infusions of norepinephrine (alpha-agonist), tyramine (catecholamine-releasing agent), and histamine, indicating the specificity of cromolyn sodium action on the mast cells. Electromicroscopic studies of pulmonary perivascular mast cells showed that a 90-min exposure to the hypoxic gas mixture reduced the total number of granules per mast cell to 75% of control. This was blocked by cromolyn sodium pretreatment. We conclude that in conscious sheep], HP[V is initiated by the liberation of a mast cell product (other than histamine) that either directly or indirectly causes pulmonary vasoconstriction.

Characterization of H1- and H2-receptor function in pulmonary and systemic circulations of sheep

We investigated the histamine H1- and H2-receptor function in the pulmonary and systemic circulations of sheep by in vivo and in vitro techniques. Combined H1 and H2 stimulation (by intravenous histamine) in vivo increased pulmonary vascular resistance (PVR) to 435% of base line and decreased systemic vascular resistance (SVR) to 49% of base line. Selective H2 stimulation (histamine after chlorpheniramine pretreatment) decreased PVR and SVR to 86 and 82% at base line, respectively, while selective H1 stimulation (histamine after metiamide pretreatment) increased PVR to 424% of base line and decreased SVR to 64% of base line. Combined H1- and H2-antagonist pretreatment completely blocked the effects of histamine on SVR, while PVR still decreased to 85% of base line, suggesting a mild "atypical" H2-receptor response in the pulmonary circulation under conditions of resting vascular tone. With increased pulmonary vascular tone (hypoxia), histamine decreased PVR to 55% (H1-antagonist pretreatment) and to 58% (combined H1- and H2-antagonist pretreatment) of posthypoxia values, respectively, demonstrating a marked atypical H2-receptor response. In vitro, both pulmonary arterial and venous strips showed a contractile dose-response to histamine, which was blocked by the H1-antagonist pyrilamine (mepyramine). In precontracted strips, both histamine and the H2-agonists (dimaprit and impromidine) elicited a relaxant response, which was neither blocked by H1-antagonist alone nor by combined H1- and H2-antagonists. We conclude that in sheep the histamine-induced pulmonary vasoconstrictor response is mediated by H1-receptors, while the pulmonary vasodepressor response is mediated by atypical H2-receptors. The systemic vasodepressor response is mediated by both H1- and typical H2-receptors.

West Nile virus in Pakistan. 1. Sero-epidemiological studies in Punjab Province

Serum samples collected during 1978-79 from residents of the Chiniot and Changa Manga National Forest (CMF) areas of Punjab Province, Pakistan, had over-all neutralizing (N) antibody positive rates for West Nile (WN) virus of 32.8% (n = 192) and 38.5% (n = 239), respectively. Comparison of the age-specific antibody rates indicated that the pattern of exposure to infection was different in the two areas. Samples from a 1968 serosurvey of residents of the CMF area had an age-specific N antibody profile similar to the 1978 CMF sample, but both the over-all N and haemagglutination-inhibition (HI) antibody positive rates were much higher in the 1968 sample. When tested against antigen prepared from the Pakistan I-746 strain of WN virus, the percentage of sera HI antibody positive and the geometric mean titre of the sera were significantly higher than when tested against the Egypt-101 antigen. One of 124 and 11 of 50 sera from the 1978 and 1968 samples from CMF exhibited detectable HI antibody against dengue-3 virus, respectively, indicating cross-reacting flavivirus antibody was present. None of the positive sera had a higher titre against dengue-3 than against WN virus, but four of the 1968 sera reacted to equal titre against both antigens. During the 1978-79 CMF survey, serum samples from domestic and wild animals were tested for WN virus antibody. Of the 317 wild birds captured, 85 were N-antibody positive. The only frequently bled mammal was the Indian cow, from which 21 of 58 samples were positive for WN antibody.

Acute pulmonary hemodynamic effects of intravenous copper sulfate: role of alpha-adrenergic system

We investigated the acute pulmonary hemodynamic effects of intravenous copper sulfate (CuSO4) infusion and its mechanism of action in six groups of conscious sheep (total 40). After 300 mg CuSO4 alone, mean pulmonary artery pressure (Ppa) increased from 10.3 to 22.5 Torr and pulmonary artery wedge pressure (Ppaw) from 3.5 to 7.6 Torr, whereas systemic arterial pressure (Psa) increased from 95 to 102 Torr. Cardiac output (Qp) decreased from 4.7 to 3.3 l/min. Pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) increased to 320 and 160% of base line, respectively. The hemodynamic changes correlated well with serum copper, which increased from a base-line value of 0.12 to 3.5 mg/dl after the CuSO4. Serum dopamine beta-hydroxylase increased from 3.2 U/l before CuSO4 injection to 5.7 after its administration, signifying activation of adrenergic nervous system. H1-histamine receptor blockade with chlorpheniramine failed to prevent the effects of CuSO4. Pretreatment with methysergide, a serotonin antagonist, partially attenuated the effects of CuSO4. Phenoxybenzamine, an alpha-adrenergic receptor blocker, and 6-hydroxydopamine, a catecholamine depleting agent, completely blocked the effects of CuSO4. beta-Adrenergic receptor blockade with propranolol enhanced the effects of CuSO4. We conclude, that, in conscious sheep, acute infusion of CuSO4 caused a marked reversible increase in PVR with a slight transient increase in SVR, and this pulmonary hypertension was produced by stimulation of the alpha-adrenergic nervous system.

Abnormal mucociliary transport in allergic patients with antigen-induced bronchospasm: role of slow reacting substance of anaphylaxis

We evaluated the possible role of slow reacting substance of anaphylaxis (SRS-A) in mediating mucociliary dysfunction in allergic asthma. In 6 asymptomatic nonsmokers with ragweed asthma, we measured specific airway conductance (SGaw) and tracheal mucous velocity (TMV) before and after bronchial challenge with ragweed extract, with or without pretreatment with 0.5% and 1% FPL-55712 (SRS-A antagonist). Mean baseline TMV was 8.9 mm/min (SD, 1.1). Placebo and FPL-55712 per se had no effect on TMV. With placebo pretreatment, the doses of ragweed extract that resulted in a decrease in SGaw by more than 35% from baseline, led to an immediate decrease in TMV to 74% of baseline (p less than 0.05), returning to baseline within 2 h. With 0.5% and 1% FPL-55712 pretreatment, doses of ragweed extract that resulted in a similar decrease in SGaw led to an increase in TMV to 130% and 126% of baseline (p less than 0.05), respectively, immediately after antigen challenge and returned to baseline 2 h postchallenge. Inhalation of 1% FPL-55712 immediately after antigen challenge prevented the decrease in TMV. These results indicate that (a) SRS-A liberated during airway anaphylaxis impairs mucous transport, and (b) the antigen-induced increase in TMV after pretreatment with an SRS-A antagonist may reflect a stimulatory effect of other chemical mediators of anaphylaxis.

Airway responses to antigen challenge in allergic rhinitis and allergic asthma

The density dependence of the maximum expiratory flow-volume curve, functional residual capacity (FRC), and specific airway conductance (SGaw) were determined before and during bronchial provocation with ragweed extract in 27 subjects with ragweed hypersensitivity and a history of either bronchial asthma (16 subjects) or allergic rhinitis (11 subjects). Mean baseline SGaw was significantly lower while mean volume of isoflow (Visov) and FrC were significantly higher in subjects with bronchial asthma. During antigen challenge, 10 of 16 subjects with bronchial asthma (63%) and five of 11 subjects with allergic rhinitis (45%) showed a greater than 35% decrease in SGaw ("reactors"): mean relative decreases in SGaw from baseline were 46% and 53%, respectively. The remaining subjects showed a less than 35% decrease in SGaw ("nonreactors") with mean relative decreases of 9% (allergic asthma) and 6% (allergic rhinitis). Mean Visov increased in all subjects with bronchial asthma and in eight of 11 subjects with allergic rhinitis. A significant increase in FRC (6%) was seen only in the "reactors" with bronchial asthma. Following antigen challenge, the beta adrenergic agonist, isoetharine, increased SGaw and decreased Visov. We conclude that in asymptomatic subjects with ragweed hypersensitivity, (1) central and peripheral airway function is more abnormal in subjects with bronchial asthma than in subjects with allergic rhinitis, (2) subjects of both groups show quantitatively and qualitatively comparable airway responses during antigen challenge with a decrease in SGaw or an increase in Visov, possibly representing increase in central and/or peripheral airflow resistance, respectively, (3) Visov may be a more sensitive indicator of airway response to antigen challenge than SGaw, and (4) the bronchodilator effects of a beta adrenergic agonist on antigen-induced bronchospasm are similar in both groups.