Impairment of human alveolar macrophage oxygen consumption, and superoxide anion production by local anesthetics used in bronchoscopy

The effect of high intensity exercise on the functional capacity of equine pulmonary alveolar macrophages and BAL-derived lymphocytes

The effect of strenuous exercise on the functional capacity of pulmonary alveolar macrophages (PAM) and bronchoalveolar lavage-derived lymphocytes was determined in eight horses prior to and after 7 weeks of training. Strenuous exercise had no effect on the total cell count or the percentage of live cells in bronchoalveolar lavage (BAL) samples prior to or following training. However, training was associated with a significant increase in the total cell count of pre-exercise BAL samples and a significant reduction in the percentage of live cells in post-exercise samples. Strenuous exercise was associated with impaired phagocytosis by PAM after 7 weeks of training but had no effect on similar samples obtained from untrained horses. The oxidative burst activity of PAM was significantly increased following strenuous exercise for both untrained and trained horses. BAL -derived lymphocyte oxidative burst was similarly affected following training. These results suggest that strenuous exercise and training may influence pulmonary immune cell function.

Effects of five amino-amide local anaesthetic agents on human polymorphonuclear leukocytes measured by chemiluminescence

The aim of this study was to assess the influence of five amino-amide local anesthetic agents on the production of oxygen metabolites in the human polymorphonuclear leukocyte (PMNL), both intra- and extracellularly. Ropivacaine, a new long-acting amino-amide local anaesthetic agent, bupivacaine, lidocaine, mepivacaine and prilocaine in concentrations 1-5 micrograms.ml-1 up to 500-1000 micrograms.ml-1 were compared to an untreated control. PMNLs were isolated from heparinized blood (healthy adult volunteers). Cells were incubated with the various local anaesthetics (37 degrees C, 30 min), then placed in a Biolumat (luminol-amplified chemiluminescence) and stimulated by formyl-methionyl-leucyl-phenylalanine (FMLP), phorbol myristate acetate (PMA) or ionomycin. Horseradish peroxidase (HRP) was added to discriminate between an intra- or extracellular response. In general, a decrease in chemiluminescence-response was seen with higher concentrations (500-1000 micrograms.ml-1) of the various local anaesthetics. Lidocaine showed a decrease even at lower concentrations. A marked increase in intracellular response for prilocaine 1000 micrograms.ml-1 (3894 mumol.l-1) accompanied by a reduction in extracellular response, using FMLP +/- HRP as a stimuli, was noted. Ropivacaine 1000 micrograms.ml-1 (3216 mumol-l-1) showed a decrease both intra- and extracellularly that was similar to, and even somewhat more pronounced than lidocaine 1000 micrograms.ml-1 (3692 mumol.l-1), when using PMA with or without HRP as the stimuli.

Effect of strenuous exercise stress on chemiluminescence response of equine alveolar macrophages

Bronchoalveolar lavage samples were collected using a fibreoptic endoscope from horses at specified times before and after single bouts of exercise. Lucigenin-dependent phagocytic chemiluminescence was used to assess the effect of exercise on the alveolar macrophage metabolic activity in response to stimulation by opsonised zymosan. A profound suppressive effect on the chemiluminescence production was present throughout the first three days after exercise. However, the cellular composition of lavage fluids was not altered by the exercise. It is suggested that strenuous exercise may jeopardize the antimicrobial function of alveolar macrophages which may lead to an increase in susceptibility to infection.

The effects of intravenous anaesthetic agents on human neutrophil chemiluminescence

Intact neutrophil function is essential for the defence against infection. Any alteration in neutrophil function, which decreases their ability to phagocytose and kill bacteria, might contribute to mortality and morbidity. We investigated the effects of clinical concentrations of thiopentone, Alfathesin, methohexitone, morphine, lidocaine and diazepam on the microbicidal oxidative function of human neutrophils. The oxidative activity was assessed utilizing the technique of chemiluminescence, which is a measure of free radical generation. Thiopentone and Alfathesin produced a significant dose dependent depression in chemiluminescence. There was a 27 per cent reduction in activity with thiopentone 5 micrograms X ml-1, a concentration equivalent to the free plasma concentration achieved following an anaesthetizing dose of thiopentone. There was a 55 per cent reduction in chemiluminescence at an alphaxolone concentration of 1.25 micrograms X ml-1, a concentration equivalent to the free plasma level obtained after induction of Alfathesin anaesthesia. The effect of thiopentone and Alfathesin was reversed by cell washing. Methohexitone, morphine, diazepam, and lidocaine caused no significant reduction in chemiluminescence over the dose ranges studied. These observations indicate that thiopentone and Alfathesin can adversely affect leucocyte function in vitro and, therefore, may contribute to impaired host resistance in the perioperative period and in the intensive care unit.

An in vitro model for studying the effects of pharmacological agents on human ciliary beat frequency: effects of lignocaine

1 The effects of lignocaine hydrochloride on ciliary beat frequency (CBF), measured photometrically in vitro, using human epithelium obtained by nasal brushing was studied in 20 healthy subjects. Above lignocaine concentrations of 2.5 x 10(-3) g/ml cilio-inhibition occurred in a dose-dependent manner. Concentrations greater than 2 x 10(-2) g/ml caused ciliostasis. 2 Lignocaine aerosol was sprayed in vivo on the mucosa of one nasal cavity in five healthy subjects and five patients premedicated for bronchoscopy. CBF, measured in vitro in nasal brushings, was not different for treated and untreated sides. 3 Variation of intrinsic CBF with time after nasal brushings were taken was studied in ten normal subjects. No significant change in CBF was found until after 24 h. 4 We conclude that lignocaine hydrochloride, at concentrations three orders of magnitude above drug levels encountered in clinical practice, inhibits human CBF in a dose-dependent manner. Aerosolised lignocaine hydrochloride in doses which produce local nasal mucosal anaesthesia, does not inhibit CBF subsequently measured in vitro. Lignocaine is a suitable local anaesthetic for use at fibreoptic bronchoscopy when samples are being obtained for study of ciliary function. 5 The measurement of CBF in nasal mucosal brushings provides an in vitro model suitable for studying the effects of pharmacological agents on human ciliary activity.