Accumulation of prostacyclin in rat brain during haemorrhagic hypotension--possible role of PGI2 in autoregulation.
The effect of haemorrhagic hypotension on the levels of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-keto prostaglandin F1 alpha (6-keto-PGF1 alpha) in cortical tissue of rats was studied. Lightly anesthetized rats were subjected to steady-state hypotension for 15 min, with a mean arterial blood pressure of 80, 60, and 40 mm Hg, and compared to a control group of normotensive rats. No significant change was found in the levels of PGE2 and TXB2. The level of 6-keto-PGF1 alpha increased from 7.8 +/- 0.9 to 14.1 +/- 1.9 pg/mg protein (p less than 0.02) at 80 mm Hg. Our findings suggest that prostacyclin, which is a potent vasodilator, might play a role in setting the lower limit of the autoregulation range.
D015121:6-Ketoprostaglandin F1 alpha / Q000378:metabolism; D000818:Animals; D001784:Blood Gas Analysis; D001921:Brain / Q000378:metabolism*; D015232:Dinoprostone; D011464:Epoprostenol / Q000378:metabolism* / Q000502:physiology*; D006470:Hemorrhage / Q000503:physiopathology*; D006706:Homeostasis; D007022:Hypotension / Q000503:physiopathology*; D008297:Male; D011458:Prostaglandins E / Q000378:metabolism; D051381:Rats; D013929:Thromboxane B2 / Q000378:metabolism
D011458:Prostaglandins E; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D011464:Epoprostenol; D015232:Dinoprostone