The intrarenal erythrocyte distribution, total renal blood flow and renal vascular resistance were studied before and during recirculation after 60 min of warm ischaemia in three groups of rabbits. One group was pretreated with superoxide dismutase, another with catalase and the third group was not pretreated at all. In non-pretreated ischaemic kidneys there was a significant trapping of labelled erythrocytes in the outer stripe of the medulla. This trapping was not seen in non-ischaemic control kidneys and was completely prevented by pretreatment with either superoxide dismutase or catalase. In non-pretreated ischaemic kidneys there was a transient increase in total renal blood flow during the first 5 min of recirculation, after which it returned to preischaemic values. After pretreatment with catalase the postischaemic increase in blood flow was more pronounced but again the blood flow returned to preischaemic values within 30 min. Pretreatment with superoxide dismutase resulted in a rapid postischaemic increase in blood flow which remained high throughout the 30 min period studied. The renal vascular resistance decreased initially during recirculation after ischaemia in both pretreated and non-pretreated kidneys. In the latter it returned to pre-ischaemic values within 10 min whereas a slower increase was observed after catalase pretreatment. After pretreatment with superoxide dismutase the resistance remained low during the 30 min recorded.

Three injectable corticosteroids, betamethasone dipropionate, beta-methasone disodium phosphate and betamethasone acetate, and methylprednisolone acetate, were compared for onset and duration of action in patients with severe seasonal allergic rhinoconjunctivitis. The sixty patients who were entered into the trial had been well-studied in our allergy clinic. They were assigned, on the basis of a random number code, to treatment with one of the corticosteroids. Following a single intramuscular injection with one of the preparations, plasma cortisol and blood glucose concentrations also were compared at days 1, 2--3, 5--7 and 14. All three preparations improved the nasal symptoms. There were no individual differences with respect to onset or to duration of action. However, there were some differences in the effects on endogenous cortisol production and on blood glucose levels. Two of the preparations, betamethasone dipropionate and methylprednisolone acetate, suppressed endogenous cortisol for more than 14 days, while betamethasone phosphate/acetate did not suppress cortisol beyond 12 days. Beta-methasone dipropionate produced a moderate increase in blood glucose concentrations for the first two days after administration; betamethasone phosphate/acetate caused an increase for one day and methylprednisolone acetate had no effect.

Renal function and morphology were studied before and after 60 min of renal ischaemia and contralateral nephrectomy in five groups of rabbits. The animals were pretreated with superoxide dismutase, catalase, allopurinol or mannitol. One group was not pretreated and served as a control. A moderate transient increase in serum creatinine concentration was observed in the control rabbits, while a significantly less pronounced increase was noted after pretreatment with superoxide dismutase, catalase and mannitol. Pretreatment with allopurinol did not significantly reduce the postoperative increase in serum creatinine and sodium excretion, but the urine osmolality returned to normal more rapidly than in the control group. The appearance under the light microscope of kidney tissue taken from surviving rabbits was found to be normal irrespective of pretreatment. Severe tubular necrosis was observed in the kidneys from rabbits that died during the observation period.

After intravenous injection of heparin (in aniounts related to the body‐weight) thc blood plasma diamine oxidase(DAO‐) activity increased transiently in all vertebrates studied (cod, frog, fowl, mouse, white rat, golden hamster, guinea‐pig, rabbit, cat, dog, goat, sheep and cow). The DAO‐response to heparin varied strongly between the species. Often with a bi‐phasic ascent, it showed a maximum (within a few minutes to about one hour) and then decreased, often in a “monoexponential” fashion, in the course of the next few hours. In anodons no significant DAO‐activity was found.—The biological significance of the heparin effect upon DAO is discussed with special reference to the coexistence of heparin and histamine in the mast cells.

No abstract