Tumor host relations. I. Increased plasma cortisol in tumor-bearing humans compared with patients with benign surgical diseases.

Plasma cortisol was measured by a protein binding technique in 81 patients with malignant tumors of different extent and various sites and in 82 patients with benign surgical diseases. The mean value of the tumor patients (x +/- s = 165 +/- 69 micrograms cortisol/l plasma) was increased significantly compared with the benign surgical disorders (100 +/- 45 micrograms/l). Within the group of patients with benign surgical disorders there was little variation by the type of disease (cortisol mean values given in brackets): benign breast tumors (95), gall stones (107), ulcer of the stomach and duodenum (96), hernia (78), appendicitis acuta (112), and struma (90). The results are in accordance with the hypothesis that glucocorticoids are involved in the increased protein catabolism of skeletal muscles and other signs of cachectic tumor patients.

Antiplatelet and anticoagulant effects of "HN-11 500," a selective thromboxane receptor antagonist.

The antiplatelet and anticoagulant effect of a thromboxane receptor (TX receptor) antagonist developed by Nycomed (Linz) has been studied in a placebo-controlled double-blind phase I study. Sixteen healthy male volunteers received different single oral doses of "HN-11 500" (C(14)H(15)NO(5)S(2); 1, 10, 100, 200, and 400 mg). Eight volunteers received placebo. The washout period between each dosage applied was at least 12 days. Platelet aggregation induced by the thromboxane mimetic "U 46 619" (C(21)H(34)0(4)) and platelet adhesion to siliconized glass were significantly and dose-dependently inhibited. The effect lasted between 3 and 4 h (10 mg) and 8 h (400 mg), respectively, and correlated well with the pharmacokinetic data. Platelet aggregation seems to be more sensitive to monitor the effects of HN-11 500 on platelet function than platelet adhesion. Plasma levels of 300 ng/ml HN-11 500 probably leads to >90% inhibition of platelet aggregation. The template bleeding time slightly increased but did not exceed the normal range. Furthermore, there was a wide variation of results. There were no significant changes in platelet counts, platelet-induced thrombin generation time (PITT), and blood coagulation parameters. All doses of HN-11 500 were well tolerated. HN-11 500 is a potent TX receptor antagonist (TXRA), which inhibits either platelet aggregation or platelet adhesion, which has not yet been described. In clinical routine, TXRAs have to demonstrate the effectiveness in large clinical trials for different clinical indications and to compete with single or combined administrations of cyclooxygenase (COX) inhibitors, thienovridines, thromboxane synthase inhibitors, and GIIb/IIIa inhibitors.

Pharmacology of a selective cyclooxygenase-2 inhibitor, HN-56249: a novel compound exhibiting a marked preference for the human enzyme in intact cells.

HN-56249 (3-(2,4-dichlorothiophenoxy)-4-methylsulfonylamino-benzenesu lfonamide), a highly selective cyclooxygenase (COX)-2 inhibitor, is the prototype of a novel series of COX inhibitors comprising bicyclic arylethersulfonamides; of this series HN-56249 is the most potent and selective human COX-2 inhibitor. HN-56249 inhibited platelet aggregation as a measure of COX-1 activity only moderately (IC50 26.5+/-1.7 microM). In LPS-stimulated monocytic cells the release of prostaglandin (PG) F1alpha as a measure of COX-2 was markedly inhibited (IC50 0.027+/-0.001 microM). Thus, HN-56249 showed an approximately 1000-fold selectivity for COX-2 in intact cells. In whole blood assays HN-56249 showed a potent inhibitory activity for COX-2 (IC50 0.78+/-0.37 microM) only. COX-1 was only weakly inhibited (IC50 867+/-181 microM). Hence, HN-56249 exhibited a greater than 1000-fold selectivity for whole blood COX-2. HN-56249 surpassed the COX-2 selectivities of the COX-2 selective inhibitors 3-cyclohexyloxy-4-methylsulfonylamino-nitrobenzene (NS-398) and 6-(2,4-difluorophenoxy)-5-methyl-sulfonylamino-1-indanone (flosulide) in the intact cell assays by eight- and threefold, respectively, and in the whole blood assays by approximately 40-fold. Following i.v. administration HN-56249 inhibited carrageenan-induced rat paw oedema only moderately (ID50 26.2+/-5.7 mg/kg, mean +/- SEM), approximately tenfold less potent than indomethacin (ID50 2.1+/-0.2 mg/kg, mean +/- SEM). After oral administration HN-56249 reversed thermal hyperalgesia in the carrageenan-induced rat paw oedema test, however, some 30-fold less potently than diclofenac. Comparing the inhibitory potency of HN-56249 against human COX-2 with that against murine COX-2 in intact cells revealed a 300-fold selectivity for the human enzyme. Similar effects were observed with other COX-2-selective arylethersulfonamides. In contrast, non-COX-2-selective arylethersulfonamides, including a highly selective COX-1 inhibitor, inhibited human and murine COX-2 approximately equipotently. In conclusion, HN-56249 is a novel potent and highly selective COX-2 inhibitor with a marked preference for the human COX-2 enzyme in vitro. Despite excellent bioavailability and the long plasma half-life of HN-56249, anti-inflammatory effects in rodents were only moderate. We suggest these differing in vitro-in vivo effects observed could be due to significant inflammatory prostaglandin synthesis by COX-1, or to the genetic differences between human and rodent COX-2, or to both.

How to collect blood for the measurement of HGH, LH, FSH, cyclic AMP, folic acid, cortisol and testosterone.

In order to estimate peptide hormones, steroid hormones, folic acid and cyclic AMP in the same blood sample we investigated the influences of different anticoagulants on the measurement. It could be demonstrated that blood collected in EDTA-coated tubes can be for the measurement of each of the mentioned constituents.

Determination of efficacy of linotroban by inducing a reduction of renal inulin/para-aminohippuric acid clearances with the thromboxane A2 mimetic U-46619 in the conscious female rat.

Linotroban (CAS 141443-73-4), a potent and selective thromboxane (TXA2) receptor antagonist, is known as a novel antithrombotic agent. It is suggested that pharmacological inhibition of TXA2 synthesis or action merits continued evaluation in the treatment of a variety of renal diseases. The aim of this study was the determination of efficacy of this new TXA2 receptor antagonist by assessing its effect on the reduction in inulin and para-aminohippuric acid (PAH) clearances induced by the TX/prostaglandin endoperoxide mimetic U-46619 in the conscious female rats. The following doses (3, 10, 30 mg/kg/24 h) of linotroban mixed with 720 micrograms TX-mimetic U-46619/kg/24 h were administered via osmotic pumps at a delivery rate of 10 microliters/h, implanted s.c. during 72 h. Rats of the U-46619 group were administered 720 micrograms U-46619/kg/24 h alone as described above, controls received 3.5% NaHCO3, respectively. Inulin/PAH clearances were determined at the end of the 4-h clearance period (68 h-72 h). Summarizing the data, glomerular filtration rate (GFR) and PAH clearances were reduced significantly by U-46619. When linotroban (3, 10 or 30 mg/kg/24 h) was added to U-46619 the GFR and PAH clearance were reversed to values that showed no significant differences to the controls.

[Binding of cortisol, fluocortolone and difluocortolone to human plasma proteins (author's transl)]. / Bindung von cortisol, Fluocortolon und Difluocortolon an Humanplasmaproteine.

The binding properties of [3H]cortisol, [3H]fluocortolone and [3H]difluocortolone by human plasma, human albumin, human- beta- and gamma-globulins have been studied by equilibrium dialysis. Cortisol, in physiological concentrations (0,4 micromol/l), is 98% bound in human plasma at 25 degrees C, fluocortolone 96% and diflucortolone 85%. Uncer physiological conditions cortisol is mainly bound to the corticosteroid binding globulin (transcortin). 2/3 of fluocortolone is bound to transcortin and 1/3 to albumin and globulins, whereas difluocortolone is mainly bound to albumin and to globulins but not to transcortin. The binding affinities of beta- and gamma-globulins are -ery low for the corticoids investigated, but they are higher for fluocortolone and difluocortolone than for cortisol.

Individual and combined effects of a thromboxane receptor antagonist and different antithrombotic agents in a rat microcirculatory thrombosis model.

The antithrombotic effect of a thromboxane A2 receptor antagonist (HN-11501:5-[2-(4-chlorophenylsulfonylamino)-ethyl]-2-thienylox y-acetic acid) alone and in combination with other antithrombotic agents has been studied in an experimental thrombosis model in which laser lesions are used to induce a defined thrombosis in rat mesenteric venules. The thromboxane receptor antagonist showed a significant and dose-dependent antithrombotic effect if given orally. The strongest additive thrombosis-inhibiting effect was observed after oral administration of HN-11501 at a dose of 2.5 mg/kg together with an intravenous infusion of 1 microgram/kg/h of a prostacyclin analogue (cicaprost). An additive antithrombotic effect was also observed after oral application of 2.5 mg/kg of HN-11501 and intravenous injection of 0.2 mg/kg of a low molecular weight heparin (Fraxiparine). The combination of 2.5 mg/kg of HN-11501 orally with an intravenous injection of 0.1 mg/kg molsidomine also had a significant additive effect. No significant additive effect was observed when 2.5 mg/kg of HN-11501 and 10 mg/kg of acetylsalicylic acid were orally administered simultaneously.

Effects of the novel thromboxane (TXA2) receptor antagonist linotroban on inulin and para-aminohippuric acid clearances in the conscious male and female rat.

This paper reports the results of experiments designed to determine the effect of linotroban (CAS 141443-73-4) a selective thromboxane (TXA2) receptor antagonist with novel antithrombotic activity, on renal function in conscious male and female rats. Linotroban was administered subcutaneously at doses of 0, 6, 24, 48 and 96 mg/kg/24 h by osmotic minipumps over 6 days. Inulin (Inutest) and para-aminohippuric acid (PAH) clearances were determined on the last day of linotroban treatment. These agents were delivered by a slow release tablet planted s.c. five days after the start of the linotroban treatment. Linotroban did not significantly alter renal functions, although there was a significant difference in GFR (glomerular filtration rate) for male and female rats receiving the highest dose. Linotroban is well tolerated but the difference in renal function between male and female rats at the highest dose may reflect a threshold of renal tolerance.

The analgesic NSAID lornoxicam inhibits cyclooxygenase (COX)-1/-2, inducible nitric oxide synthase (iNOS), and the formation of interleukin (IL)-6 in vitro.

OBJECTIVE: To investigate anti-inflammatory effects of lornoxicam in vitro on COX-1/COX-2, on NO formation from iNOS and on the formation of the pro-inflammatory cytokines TNF-alpha, IL-1beta, IL-6, and IL-8. MATERIALS AND METHODS: COX-1 inhibition in intact cells was assessed employing two systems: measurement of aggregation in human washed platelets and assessment of TXB2 formation in HEL cells. COX-2 inhibition was assessed by measuring 6-keto-PGF1alpha in supernatants of intact cells of LPS-stimulated J774.2 cells (murine) and of Mono Mac 6 cells (human). In whole blood inhibition of COX-1 was performed by measuring TXB2 formation after clotting, and COX-2 inhibition was examined in LPS-stimulated whole blood cultures. The reduction of NO levels as a measure of the inhibition of cellular NO formation was assayed in supernatants of LPS-stimulated RAW 264.7 cells using the Griess reaction. Compound influence on the formation ofTNF-alpha, IL-1beta, IL-6, and IL-8 was examined using LPS-stimulated monocytic cells (THP-1) and measurement of cytokine concentrations by specific ELISAs. RESULTS: In intact human cells, lornoxicam showed a balanced inhibition of COX-1/-2 exhibiting the lowest IC50 (0.005 microM/0.008 microM) of the large panel of NSAIDs tested. Similar results were obtained in the whole blood for COX-1/-2. NO formation was dose-dependently inhibited by lornoxicam (IC50 of 65 microM) whereas piroxicam, diclofenac, ibuprofen, ketorolac and naproxen inhibited the NO formation markedly less. Indomethacin was approximately equipotent with lornoxicam. In stimulated monocytic cells (THP-1), lornoxicam showed a marked inhibition of IL-6 formation (IC50 54 microM) while the formation ofTNF-alpha, IL-1beta and IL-8 was only moderately affected. CONCLUSIONS: Of the panel of NSAIDs tested, lornoxicam was found to be the most potent balanced inhibitor of human COX-1/-2. The equipotent COX-isoenzyme inhibition by lornoxicam is complemented by a marked inhibition of IL-6 production and of iNOS-derived NO formation. The in vitro activities described support the marked anti-inflammatory and analgesic activities of lornoxicam found in animal models as well as in clinical studies.

Selective prostaglandin G/H synthase (PGHS)-2 inhibitors show greater inhibitory activities on human PGHS-2 than on murine PGHS-2 in intact cells.

Excess eicosanoid formation during inflammation has been attributed to the expression of the gene coding for the inducible isoform of prostaglandin G/H synthase (PGHS-2). Human and murine PGHS-2 proteins differ in 73 out of the 604 amino acids. When comparing the inhibitory effects of a panel of PGHS-inhibitors in a whole cell human and murine PGHS-2 assay carried out under identical conditions, classical NSAIDs with the exception of aspirin and tenoxicam showed similar inhibitory effects on both human and murine PGHS-2 enzymes. However, the PGHS-2 selective inhibitors nimesulide, flosulide and NS398 showed a much greater inhibition of human PGHS-2. We suggest that these differences could be due to the genetic differences of human and murine PGHS-2.

Overview of the pharmacological properties, pharmacokinetics and animal safety assessment of lornoxicam.

Lornoxicam is a new, highly potent antirheumatic agent which is an oxicam derivative. Although highly potent as a cyclo-oxygenase inhibitor, the compound does not cause inhibition of 5-lipoxygenase and does not appear to shunt arachidonic acid through this cascade. This powerful inhibition of cyclo-oxygenase has manifested itself as highly potent analgesic and anti-inflammatory effects in animal studies and also prevented the bone destruction which normally occurs in the adjuvant polyarthritic rat. To explain this finding, studies have demonstrated that lornoxicam inhibits polymorphonuclear (PMN)-leukocyte migration; inhibits the release of superoxide from human PMN-leukocytes; inhibits the release of platelet derived growth factor (PDGF) from human platelets and stimulates the synthesis of proteoglycans in cartilage in tissue culture. Lornoxicam is well absorbed and has a plasma t1/2 in man of 4 hours which is distinctly different from other oxicams. It is metabolized in animals and in man to the 5'-hydroxy-metabolite which is inactive in pharmacological tests. In vitro and in vivo animal safety studies have demonstrated both subchronically and chronically that lornoxicam manifests no unusual toxicity, is not a mutagen nor is it tumorigenic and causes no fetal teratogenicity in reproduction studies.