healthy volunteers
Conditions
Interventions
Group 1: All 10 subjects will undergo the preparatory and the fMRT study part including all interventions.
1. Preparatory study part
Subjects are tested for their baroreflex response using phenylephr
Sponsors
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Luft- und Raumfahrtmedizin, Abteilung Kardiovaskuläre Luft- und Raumfahrtmedizin (KLM)
Eligibility
Sex/Gender
Male
Age
18 Years to 40 Years
Inclusion criteria
Inclusion criteria: Physically and mentally healthy male test subjects that are able and declare in writing their willingness to participate in the entire study and successfully passed the psychological and medical screening Aged between 18-40 years old with a Body Mass Index (BMI) of 19-28 kg/m2, weight between 60-100 kg, and a height between 160-195 cm Non-smoker, for at least six months before the start of the study Demonstrable medical insurance Normal blood pressure (lower than 140 over 90) intact pharmacological baroreflex heart rate response for continuing fMRI study inconspicuous routine diagnostic laboratories concerning endocrine diseases, renal or hepatic dysfunction, autoimmune diseases, musculoskeletal diseases
Exclusion criteria
Exclusion criteria: Medical history is assessed during medical inclusion. 1. Neurological conditions including strokes, brain haemorrhage, aneurysms, brain tumours, neurodegenerative diseases, seizures, head trauma based on medical history. 2. Cardiopulmonary conditions including coronary artery disease, myocardial infarction, heart failure, ventricular or atrial arrhythmias, pacemaker, recurrent syncope, autonomic disorders, chronic pulmonary diseases (COPD, severe asthma, pulmonary fibrosis), sleep apnea, insomnia or narcolepsy based on medical history. Diseases with compensatory hypertension (e.g. coarctation of the aorta, arteriovenous shunting). 3. Active or previous psychiatric conditions including depression, anxiety, bipolar disorder, ADHD based on medical history. 4. Any other medical condition that the investigators consider a contraindication to the study procedures that would make it unsafe or confound the measurements. This includes, for instance, drug, medication or alcohol abuse (regular consumption of more than 20-30 g alcohol/day), migraine, or taking medications that may impair cognitive function, autonomic function or any of the study procedures. 5. Congenital (Leber’s) optic atrophy or tobacco amblyopia. metal implants or active medical devices
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The objective of this study is to adjust the interventional baroreflex and chemoreflex activation into a fMRI compatible paradigm together with LBNP, pharmacological baroreflex testing and hypoxia/hyperoxia. It is the purpose to define the variance of brainstem activation for sample size and effect size calculations for future baroreflex, chemoreflex and interaction studies. | — |
Secondary
| Measure | Time frame |
|---|---|
| Identify the brainstem nuclei activity changes in response to baroreflex and chemoreflex mediated vagal and sympathetic activation and inhibition. Baroreflex interventions are: pharmacological (phenylephrine and sodium nitroprusside bolus technique) and lower body negative pressure (LBNP). The alpha-1 agonist increases blood pressure leading to baroreflex mediated vagal activation and sympatho-inhibition whereas LBNP is expected to cause the opposite effects. Peripheral chemoreceptors will be provoked by hypoxia and inhibited during hyperoxia. | — |
Countries
Germany
Contacts
Public ContactDarius Gerlach
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Luft- und Raumfahrtmedizin, Abteilung Kardiovaskuläre Luft- und Raumfahrtmedizin (KLM)
Outcome results
None listed