Journal of physiology and pharmacology : an official journal of the Polish Physiological Society
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J. Physiol. Pharmacol. · Dec 2008
Significance of pulmonary vagal afferents for respiratory muscle activity in the cat.
The influence of vagal stretch receptor afferents on respiratory motor-output and respiratory changes in esophageal pressure (DeltaP(es)) was studied in anaesthetized cats. Tracheal occlusions and lung inflations were performed during hyperoxic normocapnia, during electrical stimulation of one carotid sinus nerve (CSN) or the intracranial medullary chemosensitivity (MCS), during hypercapnia or the combination of CSN and hypercapnia. Tracheal occlusions during inspiration led to increased and prolonged inspiratory muscle (IM) activity. ⋯ The sensitivity of the lung reflexes is enhanced with increasing respiratory drive. The HB-inspiration inhibitory reflex limits the depth of lung inflation, whereas the HB-expiration facilitatory reflex promotes an effective lung deflation. Both reflex mechanisms, the inspiratory and expiratory one, are present in eupnoeic breathing, but play an important role during increased chemoreflex drive and obstruction of expiration, e.g., with increased external airway resistance.
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J. Physiol. Pharmacol. · Dec 2008
ReviewSystemic treatment by inhalation of macromolecules--principles, problems, and examples.
Aerosol inhalation is an established route of medical administration for the treatment of pulmonary diseases. In contrast, aerosol inhalation for treatment of systemic diseases is a novel therapeutic approach. Clinical use of the latter therapy for many years has been limited by the lack of accuracy, efficiency, and reproducibility of the administered doses. ⋯ Studies demonstrated that only a small number of morphological factors influence alveolar drug deposition (e.g., exogen allergic alveolitis, active sarcoidosis, active smoking). In consequence, an increasing number of studies investigated the systemic effect of inhaled high molecular weight substances (e.g., insulin, heparin, interleukin-2) and demonstrated that controlled aerosol therapy may serve as a non-invasive alternative for drug application by means of a syringe. Our review briefly summarizes the mechanisms for pulmonary absorption of macromolecules and gives an overview on prior research in the field of inhalant treatment of systemic diseases.