W e would like to think that dyspnea, like pain, serves as an early-warning sign of developing disease, respiratory or cardiac. To be effective as an early-warning system, dyspnea should be absent in the absence of disease, its severity should correlate with the severity of lung function impairment, and it should be unpleasant enough to call attention to itself. However, when lung function cann...

Interstitial lung diseases limit daily activities, impair quality of life and result in (exertional) dyspnoea. This has mainly been attributed to a decline in lung function and impaired gas exchange. However, the contribution of respiratory muscle dysfunction to these limitations remains to be conclusively investigated. Interstitial lung disease patients and matched controls performed body plet...

Lbx1 is a transcription factor that determines neuronal cell fate and identity in the developing medulla and spinal cord. Newborn Lbx1 mutant mice die of respiratory distress during the early postnatal period. Using in vitro brainstem-spinal cord preparations we tested the hypothesis that Lbx1 is necessary for the inception, development and modulation of central respiratory rhythmogenesis. The ...

GABAergic neurons in the caudal ventrolateral medulla (CVLM) are driven by baroreceptor inputs relayed via the nucleus tractus solitarius (NTS), and they inhibit neurons in rostral ventrolateral medulla to reduce sympathetic nerve activity (SNA) and arterial pressure (AP). After arterial baroreceptor denervation or lesions of the NTS, inhibition of the CVLM continues to increase AP, suggesting ...

The human body is critically dependent on the ventilatory control system for adequate uptake of oxygen and removal of carbon dioxide (CO2). Potent opioid analgesics, through their actions on μ-opioid receptor (MOR) expressed on respiratory neurons in the brainstem, depress ventilation. Opioid-induced respiratory depression (OIRD) is potentially life threatening and the cause of substantial morb...

Compared with naloxone, two opiate antagonists (naltrexone and S-20682) were tested in the intact dog in order to reverse respiratory depression, induced by fentanyl 50 micrograms kg-1 i.v. Respiratory rate and arterial blood-gases were measured at 5, 30, 60, 120, 180 and 240 min after the additional i.v. injection of the antagonist (1 microgram kg-1). Only S-20682, but not naloxone or naltrexo...

PreBötzinger Complex (preBötC) neurons are postulated to underlie respiratory rhythm generation. The inspiratory phase of the respiratory cycle in vitro results from preBötC neurons firing synchronous bursts of action potentials (APs) on top of 10-20 mV, 0.3-0.8 s inspiratory drive potentials. Is the inspiratory drive in individual neurons simply the result of the passive integration of inspira...

In 11 patients with moderately severe multiple sclerosis, lasting 11.2 +/- 7.3 years, in stable condition, and in 10 age- and sex-matched control subjects, we investigated lung function, respiratory muscle strength, and ventilatory control system. Respiratory muscle strength was assessed by measuring maximal inspiratory and expiratory mouth pressures (Pimax and Pemax, respectively). Respiratory...

The purpose of this study was to evaluate whether chronic heart failure (CHF) may induce changes in breathing pattern and ventilatory neural drive. We studied 45 male inpatients with CHF, (25 patients in NYHA class II, 20 in class III) and 22 sex-matched post myocardial infarction patients without left ventricular dysfunction who served as controls. CHF patients underwent right heart catheteriz...