Biomedical subjects

B R Lindgren

Publications and source records attributed to B R Lindgren.

41 records · Page 3Linked to original sources

PubMed1986

The effect of inhaled clonidine in patients with asthma.

To study the effect of inhaled clonidine on broncho-obstruction in asthmatics, 10 patients with extrinsic asthma were broncho-provoked twice with an allergen that had been shown to give positive skin prick test results. Before the provocations, saline or clonidine (75 micrograms) was inhaled via a DeVilbiss no. 40 nebulizer. Clonidine slightly improved the basal respiratory function without significantly influencing the blood pressure. There was a reduction in the allergen-evoked broncho-obstruction by 42 to 65% after pretreatment with clonidine. The eosinophilic leukocytes in peripheral blood had a slight tendency to leave the circulatory system during the provocation preceded by the clonidine treatment. These data add further evidence to the finding that clonidine may be of interest in the treatment of broncho-obstructive diseases.

Administration, Intranasal↗

PubMed1978

Inhibitory effects of imidazolines on histamine liberation from human leukocytes and on tracheal smooth muscle tone.

Antigen-induced IgE-mediated release of histamine from human leukocytes, an in vitro model of allergic reactions, was blocked by imidazole and imidazole-compounds such as oxymetazoline and clonidine. The H-2-antihistamines antagonized this effect of imidazolines. Alpha- and H-1-receptor blocking agents did not antagonize the effect. The contractile effects of the imidazolines were tested on tracheal preparations from the cow and guinea-pig. Imidazole was found to be a rather potent contracting agent, while oxymetazoline only caused weak contractions. Clonidine relaxed the tracheal muscles, when used in the concentration range which were inhibitory in the leukocyte experiments. The contractions caused by imidazolines were non-competitively inhibited by clemastine, while the relaxing effects were blocked by a combination of propranolol, phentolamine and cimethidine. The results suggest that imidazolines which inhibit histamine release and relax bronchial smooth muscles may be of therapeutic importance in the treatment of human allergic disorders.

Animals↗

PubMed1978

Changes in histamine and cyclic nucleotide levels after bronchoprovocation in patients with extrinsic asthma.

The contents of histamine and cyclic nucleotides were studied in leukocytes before and after a bronchoprovocation test on patients with extrinsic asthma. The bronchospastic response correlated significantly with the reduction of the amount of histamine in leukocytes isolated after the provocation. The leukocytes cyclic AMP and cyclic GMP contents were slightly reduced after the provocation, while the plasma level of cyclic AMP was markedly increased. The beta-adrenoceptor response was tested on leukocytes, before the provocation. A normal elevation of the cyclic AMP content was obtained when the leukocytes were stimulated with isoprenaline, but after the provocation, isoprenaline had no significant effect. Only when a phosphodiesterase inhibitor was present did isoprenaline increase the cyclic AMP level in the postprovocation tests. It is suggested that the mediator release from the immunologic target cells is of importance for the bronchospastic response and that a desensitization of the beta-adrenoceptors of these cells is evident after bronchoprovocation.

1-Methyl-3-isobutylxanthine↗

PubMedDate not supplied

Angiotensin-converting enzyme inhibitors and their influence on inflammation, bronchial reactivity and cough. A research review.

Synthetic orally active angiotensin-converting enzyme (ACE) inhibitors have been successfully used in the treatment of congestive heart failure and hypertension, particularly in hypertensive subjects with increased renin-angiotensin-aldosterone-system activity. Adverse skin reactions, angioneurotic oedema and rapidly decreasing lung function in asthmatics have been reported following medication with ACE inhibitors. Furthermore, these drugs have been associated with a persistent dry cough in subjects without previous known bronchial hyper-reactivity. There is reason to believe that an ACE inhibitor-induced cough is due to an increased inflammatory state in the airways of susceptible individuals, and that this cough might thereby have pathophysiological features in common with the cough seen as an early symptom of asthma. All inflammatory responses, wheal and flare reactions, infiltration of neutrophils, eosinophils, basophils and monocytes were enhanced by ACE inhibitors. A dose-response relationship for the proinflammatory effect of the ACE inhibitor has been demonstrated.

Angiotensin-Converting Enzyme Inhibitors↗

PubMedDate not supplied

The osmotic effect of glycerol on the stria vascularis and endolymph.

In the chinchilla, quantitative changes in strial thickness, area of the endolymphatic space, serum osmolality, and serum levels of glycerol, glucose, total protein sodium, potassium and chloride were determined at 1, 2, 3 and 5 h after the intraperitoneal administration of 6 g/kg glycerol. The serum osmolality, glycerol, glucose and potassium levels increased, while serum sodium and chloride decreased. Quantitative changes in cochlear structure included an increase in strial thickness and a decrease in area of the endolymphatic space. In all the animals (n = 50), the increase in strial thickness was closely correlated (correlation coefficient r = 0.57) to an increase in serum osmolality. This correlation with strial thickness improved (R = 0.71) when the interval between injection and animal sacrifice was used in combination with serum osmolality. The increase in stria thickness was also closely correlated to an increase in serum glycerol and to a decrease in serum chloride. A decrease in endolymphatic volume was found most consistently at 3 h after the i.p. administration of glycerol.

Animals↗