Prostanoid production in varicose veins: evidence for decreased prostacyclin with increased thromboxane A2 and prostaglandin E2 formation.

In this study, formation of arachidonic acid-derived prostanoids was investigated in saphenous veins of varicosed and nonvaricosed patients, all undergoing saphenectomy respectively for varicosis or in preparation for coronary bypass operation. Venous production of prostacyclin (PGI2), thromboxane A2 (TXA2) and prostaglandin E2 (PGE2) was assessed by bioassay and/or radioimmunologic assays as appropriate. Fragments of saphenous veins from varicosed patients produced significantly less PGI2 and more TXA2 and PGE2 than those from the control patients. Addition of arachidonic acid to incubation mixtures dose dependently increased release of these prostanoids, but the levels of PGI2 produced were consistently lower in veins from varicosed patients. No differences were found in varicosed patients between various segments of the same vein, no matter whether macroscopically affected or unaffected. These results demonstrate that the cyclooxygenase pathway in the venous wall of subjects with varicosis is shifted toward lesser formation of PGI2 and higher production of proaggregatory and proinflammatory prostanoids such as PGE2 and TXA2. These biochemical changes may be relevant to inflammation and thrombogenesis in varicosis.

[The kidney in shock. A new experimental method for the induction of controlled shock. I]. / Il rene da shock. Nuova tecnica sperimentale per l'induzione dello shock controllato. Nota I.

In this research we identify a new experimental model to study the shock-kidney, since this complication occurs with discreet frequency during high surgery operation. The model that better reproduce the surgical shock-kidney is the controlled hypovolemic shock. We used for this experiment five pigs of weight between 40 and 50 kg and were studied the following data: Ecg, arterial pressure, central venous pressure, diuresis (by incannulation of both ureters), renal arterial flow, levels of the renin in the renal vein. The measurements were made before, during and after the shock. The hypovolemic shock was induced by removing from carotid artery a sufficient quantity of blood to bring the pressure to 45-50 mmHg. This pressure level was kept constant for 120 min and then was reported to normal level by introducing the blood previously removed. During the experiment no kind of drugs were used.

[The kidney in shock. Changes of some hemodynamic and bio-humoral parameters. II]. / Il rene da shock. Andamento di alcuni parametri emodinamici e bio-umorali. Nota II.

In our experiments on 5 pigs of weight between 40-50 kg we've noticed changes of the parameters occurring precociously during the initial stage of the shock. Particularly we observed a sudden reduction of diuresis reaching total anuria in 15 min and persistence of this anuria for the entire time of the shock (120 min). Immediately after introduction of the removed blood the arterial pressure and the diuresis return to normal value. Concerning the blood flow in renal artery it was observed a gradual decreasing to 10-30 ml/min (normal value = 120-180 ml/min). After the restoration of the blood volume we did'nt notice a clean resumption of the flow although arterial pressure reached normal levels (flow value = 70% of the basal value). The hematic level of K+ undergoes a sudden increase that reaches. Maximal level compatible with animal's life. Within 45-60 min from the beginning of the shock and than decrease with restarting of the diuresis. Creatinine reaches 2 mg/ml in 60 min and remain constant during the following 120 min. The value of the plasma renin were precociously raised, reaching values particularly elevated after 90-120 min from the beginning of the shock and decreasing rapidly with the introduction of the removed blood (parallel behaviour of the arterial pressure).