The blood-brain barrier regulates the passage of peripheral built appetite-suppressing
hormones from the blood to the brain and informs the brain about the nutritional- and energy
status.
The aim of this study is to investigate in which extent the hormones are able to overcome the
blood-brain barrier and how long it takes after food intake. Relating thereto indications to
the effect of peripheral hormones in the central nervous system and the role of these
hormones in the development of overweight are provided.
In this study 30 patients (10 per intervention group) will be recruited. The patients are
hospitalized in the local neurosurgery and they have a CSF-drainage due to their neurological
primary disease or due to neurosurgical interventions. The patients are examined in each case
on the same day.
Simultaneous samplings of blood and CSF are taken from 10 patients after an oral glucose
tolerance test. These interventions are carried out to investigate in which extent the
appetite-suppressing hormones (e.g. Leptin, Insulin, GLP 1 and Glucagon) reach the liquor and
so the central nervous system.
In order to understand the temporal sequence, simultaneous samplings of blood and CSF are
taken from 10 other patients at certain points throughout the day.
In a further group of 10 patients will be investigated how the central effective insulin
modulates the transport of the other appetite-suppressing hormones. Therefore samplings of
blood and CSF are investigated before and after intranasal insulin administration.