ABSTRACT
It is still contradictory whether PGI_2 and TXA_2 can influence hepatic is-chemic damage. Rats were divided into three groups at random. Group 1 and 2 were givensaline; group 3 were pretreated with indomethacin. 30 min before the induction of liverischemia drugs were injected into peritoneal cavity. After 2 h of ischemia and 2 hof reperfusion, the results showed that the TXB_2 content of ischemia group was higherand the P/T ratio was lower than that of the indomethacin group. The control groupshowed no change. Massive necrosis was observed in the ischemia group, but only focalnecrosis was seen in the indomethacin group. There was no hepatic necrosis in the controlgroup. The results suggested: 1. TXA_2 was an important cell injury agent; 2. Indomethacinhave protective effect on the reperfusion liver cell injury.
ABSTRACT
The change of plasma TXB_2 and 6-Keto-PGF_1? which were stable metabolites of TXA_2 and PGI_2 respectively were observed in arterial blood of SHR and WKY and in different ages of SHR. The 6-Keto/TXB_2 ratios were computed. The results showed that TXB2 concentration of arterial blood were significantly higher in SHR than in WKY(1217.9?298.5Pg/ml vs 207.1?59.8Pg/ml, P
ABSTRACT
The changes of hemodynamics and hypoxic pulmonary vasoconstriction (HPV) inducedby cigarette smoking and the role of prostaglandins(PGs) and leukotrienes (LTs) were studied in rats. During smoking, systemic and pulmonary vascular resistance (SVR and PVR) increased 47% and 39%, respectively. The level of TXB_2 rose by 144% in plasma and 69% in lung tissue. HPV increased two-fold after smoking (△PVR increased from 55% to 102%). LTs receptor antagonist, LY-171883, prevented the smoking-in duced increase of SVR and PVR and augmentation of HPV. Cyclooxygenase inhibitor, in domethacin, prevented partly increase of PVR but not HPV induced by smoking. Our results suggest that smoking leads to pulmonary and systemic vasoconstriction and augmentation of HPV mediated by LTs, the increase of PVR during smoking is also mediated by TXA_2, This study also found that LY-171883 inhibited HPV by 72%, the result indictates that LTs mediate HPV in Wistar rats.
ABSTRACT
Acute ligation of the common carotid artery on one side internal carotid artery on opposite side resulted in experimental cerebral ischemia in rabbit. Measurement of thromboxane B_2 (TXB_2) and 6-Keto-prostaglandin F_(1?)(6-Keto-PGF_(1?))in rabbit plasma were done by radioimmunoassay. Blood samples were collected from the peripheral vein and internal carotid vein. The results were as follows:1. The concentration of TXB_2 in rabbit cerebral ischemia (ligation after 30 min.) was significantly (P
ABSTRACT
The peripheral venous plasma levels of TXB_2 and 6-Keto-PGF_(1?) were determined by radioimmunoassay in 31 control subjectsandand 51 patients with acute cerebral infarction(ACI).In ACI patients, the plasma TXB_2 levels were significantly higher than those in control subjects (P
ABSTRACT
In order to investigate the significance of prostacyclin and throm-boxere A2 in the pathegertsis of ischemic renal injury,the level of 6-keto-PGF1? and TXB2 in the plasma and the dissected slices of the kidneys of the rabbits with iscbemic renal injury was determined with RIA,It was found that 6-keto-PGF1? increased significantly in the outer and inner medullae,TXB2 increased significantly in all the renal slices,and the 6-keto-PGF1?/TXB2 ratio decreased significantly in the outer cortex 3 hours after reperfusion,The findings suggest that the imbalance between the synthesis of prostacyclin and thromboxane A2 might be resporsible for the decline and redistribution of renal blood flow in the early stage of acute ischemic renal failure.
ABSTRACT
The changes of the spinal cord blood flow(SCBF),the content of TXB2 and 6-keto-PGF1a of the injured segment of the cord and other neurological manifestations were observed on a rat model of spinal cord injury(SCI)established with Allen's weight drop(50g-cm)method and the effects of indomethacin on these changes were studied.It was found that SCBF was significantly reduced in the first 2 hours after SCI and further reduced in the 4th ~ 8th hour.Increase of TXB2 was observed in the 1st hour and reached the peak in the 4th hour.The level of 6-keto-PGF1a was also increased in the 1st hour and maintained at that level for 24 hours.The changes of TXB2/6-keto-PGF1a was similar to those of TXB2.There was a negative correlation of SCHF with TXB2 content and TXB2/6-keto-PGF1a ratio.The intravenous injection of 10mg/kg indomethacin could inhibit the increase of TXB2 content and increase 6-keto-PGF1a content relatively.It could also alleviate or retard the decrease of SCBF after SCI and improve the motar function of the hind limbs of the rats.These findings suggest that indomethacin can improve SCBF and promote the recovery of neurological functions through its regulatory effects on the levels of TXB2 and 6-keto-PGF1a
ABSTRACT
The changes of mean pulmonary arterial pressure (PAP) and 6-keto-PGF1a and TXB2 in the plasma and lung tissues of 3 groups of dogs (7 in each group) with blast injury (group Ⅰ),high velocity shell fragment injury on one of the extremities (group Ⅱ),and combined injury of the both (group Ⅲ) were investigated.It was found that PAP and TXB2 in the plasma and lung tissues increased after all the 3 kinds of injuries.The changes of PAP was most marked in group Ⅰ while those of TXB2 was more marked in groups Ⅲ and Ⅲ than in group Ⅰ.6-kcto-PGF1a increased in the plasma and lung tissues after blast and shell fragment injury but decreased in the plasma and showed no changes in the lung tissues after combined injury.The significance of these changes of 6-keto-PGF1a and TXB2 in the 3 kinds of injuryies were discussed.