Stabilization of rat liver lysosomes by new anti-inflammatory steroids in vitro

Steroid acid esters, synthesized by modifying the 17-ketol side chain of prednisolone, were tested for their in vitro ability to stabilize heavy mitochondrial lysosomes prepared from rat liver. Membrane stabilization was determined by assessing capability of steroids to decrease extrusion of the marker enzymes (acid phosphatase, beta-glucuronidase and aryl sulfatase) from lysosomes incubated in hypo-osmotic sucrose-Tris acetate buffer. Results indicated that prednisolone (1) significantly inhibited the lysosomal release of acid phosphatase as did the new anti-inflammatory steroid, methyl 20-dihydroprednisolonate. Methyl prednisolonate exhibited weak membrane stabilization capacities and 20-dihydroprednisolonic acid, a metabolic product of methyl 20-dihydroprednisolonate, showed virtually no membrane stabilization.

Local antiinflammatory activity of acid ester derivatives of prednisolone

The antiinflammatory activity of two steroid acid esters, methyl prednisolonate and methyl 20-dihydroprednisolonate, synthesized by modifying the 17 beta ketol side chain of prednisolone has been investigated in the cotton pellet granuloma bioassay in rats. The inhibitory effect of the ester derivatives on granuloma formation was equivalent to that of the parent compound. At dose of 5 mg/cotton pellet, methyl prednisolonate exhibited a highly significant thymolytic effect comparable to that of prednisolone, while methyl 20-dihydroprednisolonate had a weaker thymolytic effect. However, the local antiinflammatory activity of the two esters was not accompanied by a decrease in adrenal weight observed with the parent compound.

Antiinflammatory activity of two novel derivatives of prednisolone

The antiinflammatory activity of two new steroids synthesized by modifying the 17 beta-ketol side chain of prednisolone to the glycolate and glyoxylate methyl esters has been investigated in the carrageenin pedal edema test in rats. The two ester derivatives retained anti-inflammatory potency, nearly equivalent to that of the parent compound, when administered subcutaneously at the site of inflammation. However, the glyoxylate ester, when administered by systemic route, showed a weaker suppression of inflammation. The glycolate ester showed a reverse trend in that it was more effective when it was administered by systemic route than when it was applied topically.

Stereoselective effects of cis- and trans-cyclopropylbis (dioxopiperazines) related to ICRF-159 on metastases of hamster lung adenocarcinoma

The synthesis for cis-4,4' (1,2-cyclopropanediyl)bis(2,6-piperazinedione) (cis-3) is discussed. Stereoselective effects on metastases of cis-3 and the previously reported trans-2 isomer were compared to conformationally mobile ICRF-159 using a Syrian hamster lung adenocarcinoma (LG1002). Whereas ICRF-159 and cis-3 significantly inhibited lung metastases the trans-2 isomer significantly increased the number of metastatic nodules in the lung. Thus, these studies have revealed that, at least in one tumor model, antimetastatic activity can be separated from metastatic potentiating activity by controlling drug geometry.

Ventricular aneurysmectomy for the treatment of intractable angina pectoris

Resection of a large postinfarctional ventricular aneurysm led to termination of intractable angina pectoris in one patient. The patient has been followed for 5 years and remains angina-free, even though aorto-coronary bypass surgery was not performed in this patient. The patient presented no evidence of congestive heart failure, arterial emboli, or cardiac arrhythmia before or after the surgery. Intractable angina alone in the absence of congestive heart failure, systemic embolism, and refractory ventricular tachyarrhythmia may constitute another indication for ventricular aneurysmectomy with or without concomitant aorto-coronary bypass surgery.

Oxidation of corticosteroids to steroidal carboxylic acids by an enzyme preparation from hamster liver

Enzyme activity which catalyzes the oxidation of 11-deoxycorticosterone to 21-oic acids accompanies the "detritiating" enzyme (isomerase) of hamster liver recently isolated by Martin, K. O., et al. ((1977) Biochemistry 16 (preceding paper in this issue)). The metabolites isolated were 20alpha- and 20beta-hydroxy-3-oxo-pregn-4-en-21-oic acid and 3,20-dioxo-pregn-4-en-21-oic acid. When 21-hydroxy[4-14C, 21-3H]pregn-4-en-3,20-dione was the substrate, about half of the tritium was retained in position 20 of the hydroxy acids. The system which catalyzes the conversion of the ketol side chain of corticosteroids to acid metabolites appears to be a cluster of closely related enzymes. As a result of these studies, we believe that the hamster liver enzyme preparation provides a useful model system for studies on the biosynthesis of acid metabolites of the corticosteroids in man.

Study of trans-cyclopropylbis (diketopiperazine) and chelating agents related to ICRF 159. Cytotoxicity, mutagenicity, and effects on scheduled and unscheduled DNA synthesis

The cytotoxicity, mutagenicity, and DNA damaging potential of trans-cyclopropylbis (diketopiperazine) (3) and chelating agents related to ICRF 159 (1) were examined as a function of concentration and duration of exposure in the Chinese hamster cell line V79A. At a concentration of 10(-3) M, 1 and the trans-cyclopropanediamine tetraacid 8 and ester 7 proved to be cytotoxic and mutagenic. The trans-cyclopropyl analogue 3 of ICRF 159 and acyclic tetraacid 6 were less cytotoxic at all concentrations; analogue 3 exhibited no mutagenic activity at any of the concentrations tested. Compounds 1, 7, and 8, at lethal concentrations, exhibited significantly different mutation frequencies with 7 being sixfold more mutagenic than 8 at the same molar concentration. At 10(-3) M compounds 8 was several times more effective blocking DNA replication than other analogues but did not induce unscheduled DNA synthesis as did 1,3, and 6. With the exception of 8, there was an excellent correlation between mutagenesis and the induction of unscheduled DNA synthesis.

Acidic metabolite of prednisolone

The metabolic fate of the 17beta-ketol side chain of (21-3H) prednisolone was studied with an enzyme preparation from male golden hamster liver. The acidic metabolite of prednisolone was identified by mass spectrometry as 11beta, 17alpha,20epsilon-trihydroxy-3-oxo-1,4-pregnadien-21-oic acid. The enzyme showed substrate specificity, depending on the nature of substituent on the steroid nucleus.

Atypical progressive angina pectoris caused by a congenital coronary-pulmonary shunt and coronary atherosclerosis

A 57-year-old man with atypical progressive angina caused by congenital coronary-pulmonary shunt and coronary atherosclerosis is described. The angina was rather consistently unresponsive to nitroglycerin. Following closure of the shunt and aortocoronary bypass surgery, the patient became asymptomatic and has remained free of angina 2 year postoperatively. Although the congenital anomaly is rare in adults, it may be considered in the differential diagnosis of atypical angina pectoris, particularly when there is either continuous murmur or systolic murmur over the lower parasternal area.

Interactions of selenium, cadmium and copper in sheep

Cadmium supplements (7 5 or 15 mg/day) significantly Increased cadmium concentrations in blood, liver, kidney and muscle in sheep and reduced the concentrations of copper and blood and liver. The small amount of selenium released in the rumen from heavy selenium pellets increased selenium levels in blood, liver, kidney and muscle but did not reduce the concentrations of cadmium In these tissues significantly nor counteract the effect of cadmium on copper storage.