Chronically increased intra-abdominal pressure produces systemic hypertension in dogs.
OBJECTIVE
Determine if increased intra-abdominal pressure (IAP) alone can cause systemic hypertension in a chronic canine model.


METHODS
Evaluate effects of increase in IAP with progressive inflation and deflation of an intra-abdominal balloon on systemic blood pressure in experimental and control animals.


METHODS
Male dogs weighing 15-25 kg underwent placement of an intra-abdominal balloon which was progressively inflated on a weekly basis in the experimental animals (5) over 4 weeks to 25 mmHg above baseline and kept there for an additional 2 weeks before gradual deflation over 2 weeks. Control animals (5) had the balloon placed but not inflated. Pain was controlled with osmotic analgesic pumps.


METHODS
The animals were anesthetized, blood pressure (BP) measured and blood drawn for plasma renin activity (PRA), aldosterone, atrial naturetic peptide (ANP), catecholamines, and serum sodium (Na). A right heart catheter was inserted for measuring cardiac output (CO) and pulmonary artery occlusion pressure (PAOP) at baseline, week 5 (maximal IAP) and week 7 (after balloon deflation). The animals were weighed and urinary bladder pressures recorded weekly before and after abdominal balloon inflation.


RESULTS
Systolic (122+/-3 to 155+/-5 mmHg, P<0.05) and diastolic (82+/-4 mmHg to 107+/-7 mmHg, P<0.05) BP rose at 5 weeks at 25 mmHg IAP>baseline and returned to control with balloon deflation. Both systolic and diastolic BP rose (P<0.05) above control animals BP at 15 mmHg IAP at 2 weeks and remained elevated until abdominal decompression, at week 7. There were no significant changes in net animal weight, PRA, aldosterone, ANF, catecholamines, Na, CO or PAOP.


CONCLUSIONS
Increased IAP from progressively inflating an intra-abdominal balloon in dogs was associated with significant increases in systolic and diastolic BP that resolved with balloon deflation. Increased IAP may be a cause for systemic hypertension in central obesity and pre-eclampsia.
Division of General/Trauma Surgery, Department of Surgery, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA 23298-0519, USA.
G L
GL
Bloomfield
H J
HJ
Sugerman
C R
CR
Blocher
T W
TW
Gehr
D A
DA
Sica
D000005:Abdomen / Q000503:physiopathology*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D004195:Disease Models, Animal; D004285:Dogs; D006439:Hemodynamics / Q000502:physiology; D006728:Hormones / Q000097:blood; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D011312:Pressure / Q000009:adverse effects; D012964:Sodium / Q000097:blood
D006728:Hormones; D012964:Sodium