Increase in intra-abdominal pressure raises brain venous pressure, leads to brain ischaemia and decreases brain magnesium content.
BACKGROUND
Intra-abdominal hypertension (IAH) may increase brain venous pressure, which may lead to brain injury. The aim of the present study was to analyse the effect of IAH on brain venous pressure and brain total and ionised magnesium (tMg and iMg), calcium (Ca) and zinc (Zn) contents in rats.


METHODS
Forty four adult Wistar rats were examined. Animals were divided into two groups: control, and IAH: rats with intra-abdominal pressure (IAP) elevated to 25 mmHg. IAP was measured directly in the abdominal cavity. After retrograde cannulation of the jugular vein, the jugular venous pressure (JVP) was measured as the brain venous pressure. JVP and IAP were noted after induction of anaesthesia, immediately following induction of IAH and 90 min after induction of IAH. In all rats, brains were removed for biochemical and histological analysis.


RESULTS
Biochemical analysis was performed in 30 rats, histological visualisation in 14. IAP elevated to 25 mmHg increased JVP in the IAH group. After 90 min, JVP decreased; however, its value was still higher compared with pre-IAH. In the IAH group, tMg and iMg were significantly lower than in the control group. Moreover, Ca and Zn levels were higher in the IAH group compared with the control group. The histological examination showed changes indicative of ischaemic neuronal cell stress.


CONCLUSIONS
Firstly, increase in IAP elevates JVP. Secondly, raised JVP decreases tMg and iMg. Thirdly, raised JVP increases the Ca and Zn content in the rat brain. Fourthly, IAH leads to changed characteristics of brain ischaemia.
Department of Neurosurgery and Paediatric Neurosurgery, Medical University of Lublin, Poland.
Bozena
B
Jarosz
Wojciech
W
Dabrowski
Andrzej
A
Marciniak
Piotr
P
Wacinski
Ziemowit
Z
Rzecki
Edyta
E
Kotlinska
Jacek
J
Pilat
D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002545:Brain Ischemia / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D059325:Intra-Abdominal Hypertension / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D008274:Magnesium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014690:Venous Pressure / Q000502:physiology*
D008274:Magnesium