A B S T R A C T Relief of unilateral ureteral obstruiction (UUO) of 24 h duration in rats is followed by severe renal vasoconstriction in the postobstructive kidney (POK). The present study examined possible roles of renal prostaglandins (PG) and thromboxanes (TX), as well as the renin-angiotensin system, in this vasoconstriction.Administration of the cyclooxygenase inhibitor indomethaciin, which blocks both PG and TX production, failed to improve POK hemodynamics in UUO rats. To explore the possible role of the TX compounds, which include the potent vasoconstrictor thromboxane A2 (TXA2), UUO rats were infused with imidazole, an agent that blocks synthesis of TX, but not of PG. Imidazole led to two-to threefold increases in the clearance of both inulin and p-aminohippuric acid by the POK. This effect of imidazole was abolished by indomethacin, suggesting that the amelioration of POK vasoconstriction by imidazole was a result of inhibition of vasoconstrictor TX synthesis (e.g. TXA2), with PG vasodilators (e.g. PGE2 or PGI2) still active. Urea, infused in a solution whose osmolality and voluime were identical to the imidazole infusion, failed to improve hemodynamics in the POK, making it unlikely that nonspecific effects of volume expansion or osmotic diuresis mediated the beneficial effect of imidazole.Further studies examined the possible role of the renin-angiotensin systems in the vasocoinstriction of the POK. UUO rats infused with the angiotensii II Ai al)stract of this work was published in 1978. Clin. Res.

Lithium carbonate may attenuate the incidence and severity of infection associated with cancer chemotherapy but does not appear to improve patient survival. Of 100 patients with small-cell lung cancer receiving an identical regimen of cyclophosphamide, doxorubicin, and vincristine, 40 were assigned to treatment with lithium concurrently. To date, 60 patients have died, including 14 who died suddenly of apparent cardiovascular causes without evident progression of neoplastic disease or concurrent illness. Thirteen of the 14 sudden deaths were among 50 patients with clinical or electrocardiographic evidence of cardiovascular abnormalities before study entry. Among patients with pretreatment cardiovascular abnormalities, lithium administration was associated with a greater risk of sudden death and shorter survival. A strong interaction for risk of death was evident between lithium treatment and the use of bronchodilators. In multivariate analysis, the major predictors of patient survival were the quality of tumor response and treatment with lithium with or without bronchodilators. Lithium treatment is a major risk factor for sudden death in cancer patients with pretreatment cardiovascular changes receiving combination chemotherapy including an anthracycline antibiotic.

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