Head injury induces increased prostaglandin synthesis in rat brain.
Head injury was induced in the left hemisphere of rats. The rats were killed at various time intervals after trauma (immediately, 15 min, 1 and 18 h, and 4 and 10 days), and the rates of synthesis and release of prostaglandin PGE2, 6-keto-PGF1 alpha, and thromboxane TXB2 from cortical slices of both hemispheres were studied. The rate of synthesis of PGE2 after 18 h was six and four times higher than control in the contused and contralateral hemispheres, respectively. By 10 days post-trauma, both hemispheres had normal rate of PGE2 release. TXB2 and 6-keto-PGF1 alpha synthetases were affected already 15 min after the injury, and a similarly elevated rate of synthesis was found in both hemispheres. The maximal effect was detected after 1 or 18 h with return to normal after 4 or 10 days for TXB2 and 6-keto-PGF1 alpha, respectively. Tissue specific gravity was determined for both hemispheres using linear gradient columns. The results of these determinations indicate that development of edema occurs in the contused hemisphere as early as 15 min post trauma; it reaches its maximal level at 18 h and returns to normal at 10 days. Arterial pressure was monitored, and a transient increase was found at 10 min post trauma. We suggest that the production of edema after brain injury may be related to the increased rate of PGE2 and PGI2 synthesis, which occurs at similar time intervals after injury.
Shohami
E
E
Shapira
Y
Y
Sidi
A
A
Cotev
S
S
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D001794:Blood Pressure; D001921:Brain / Q000378:metabolism*; D001929:Brain Edema / Q000209:etiology; D006259:Craniocerebral Trauma / Q000378:metabolism*; D015232:Dinoprostone; D008297:Male; D011453:Prostaglandins / Q000096:biosynthesis*; D011458:Prostaglandins E / Q000096:biosynthesis; D051381:Rats; D013929:Thromboxane B2 / Q000096:biosynthesis
D011453:Prostaglandins; D011458:Prostaglandins E; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D015232:Dinoprostone