PHYSIOLOGICAL PHENOMENA
Conditions
Keywords
Water drinking, osmoreceptors, autonomic failure, syncope, blood pressure, liver transplant
Brief summary
In patients with autonomic dysfunction water drinking elicits a pressor response mediated by sympathetic activation. If any, in healthy subjects there is only a slight increase in blood pressure. However, the sympathetic activation is observable by resting energy expenditure increases greater than 20%. The investigators believe that the response to water may be mediated through sympathetic activation elicited by osmosensitve spinal afferents in the liver. Therefore, the investigators want to test water in liver transplant patients who have a denervated liver. Kidney transplant patients serve as control subjects. The investigators hypothesize that the increase in norepinephrine after water drinking is blunted in liver transplant recipients.
Interventions
DIETARY_SUPPLEMENT500ml water intake
subjects have to ingest 500ml water within 5 minutes after resting 30 minutes in supine position
Sponsors
Hannover Medical School
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* 3 to 24 month past liver or kidney transplantation * age 18 to 60 * written informed consent * ability to understand the oral and written information
Exclusion criteria
* pregnancy or lactation * transplantation of another organ * chronic heart or vascular disease * known alcohol or drug abuse * psychiatric diseases (e.g. chronic depression, schizophrenia, drug addiction)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| norepinephrine plasma level | 30-40 minutes after water drinking |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| pressure response | blood pressure 30-40 minutes after water drinking | cardiovascular changes are monitored by finapress and ICG |
Countries
Germany
Outcome results
None listed