LAS 31180 (3-methylsulphonylamino-1-methyl-4(1H)-quinolone, CAS 137338-43-3) was found to have positive inotropic and vasodilator properties through its inhibitory action on type 3 phosphodiesterase. The inotropic effects of LAS 31180 were demonstrated in vitro both in isolated guinea-pig ventricular strips (EC50 of 1.2 mumol/l) and in isolated guinea-pig working hearts. In conscious chronically instrumented Beagle dogs, LAS 31180 administered either by intravenous or oral route, showed a dose-dependent, long-lasting positive inotropic effect with minimal effects on heart rate. In hypertensive Beagle dogs LAS 31180 elicited a potent and long-lasting fall in blood pressure.

Phosphodiesterase 4 (PDE4) inhibitors, i.e. rolipram, are being extensively investigated as therapeutic agents in several diseases. Emesis is one of the most common side effects of PDE4 inhibitors. Given the fact that the area postrema is considered the chemoreceptor trigger zone for vomiting, the present study investigates the regional distribution and cellular localization of the four gene transcripts of the PDE4 subfamily (PDE4A, PDE4B, PDE4C and PDE4D) in human brainstem. In situ hybridization histochemistry was used to locate the mRNA distribution of the four PDE4 subfamilies in the area postrema and related nuclei of human postmortem brainstem. We have found that in the brainstem PDE4B and PDE4D mRNA expression is abundant and distributed not only in neuronal cells, but also in glial cells, and on blood vessels. The hybridization signals for PDE4B and PDE4D mRNAs in the area postrema were stronger than those in any other nuclei in the brainstem. They were also found in vomiting-related nuclei such as the nucleus of the solitary tract and the dorsal vagal motor nucleus. These findings suggest that cAMP signaling modification in the area postrema could mediate the emetic effects of PDE4 inhibitors in human brainstem.

Background and purpose: The chemokine receptor CCR1 is a potential target for the treatment of rheumatoid arthritis. To explore the impact of CCR1 blockade in experimental arthritis and the underlying mechanisms, we used J-113863, a non-peptide antagonist of the mouse receptor.Experimental approach: Compound J-113863 was tested in collagen-induced arthritis (CIA) and three models of acute inflammation; Staphylococcus enterotoxin B (SEB)-induced interleukin-2 (IL-2), delayed-type hypersensitivity (DTH) response, and lipopolysaccharide (LPS)-induced tumour necrosis factor alpha (TNF alpha) production. In the LPS model, CCR1 knockout, adrenalectomised, or IL-10-depleted mice were also used. Production of TNF alpha by mouse macrophages and human synovial membrane samples in vitro were also studied.Key results: Treatment of arthritic mice with J-113863 improved paw inflammation and joint damage, and dramatically decreased cell infiltration into joints. The compound did not inhibit IL-2 or DTH, but reduced plasma TNF alpha levels in LPS-treated mice. Surprisingly, CCR1 knockout mice produced more TNF alpha than controls in response to LPS, and J-113863 decreased TNFa also in CCR1 null mice, indicating that its effect was unrelated to CCR1. Adrenalectomy or neutralisation of IL-10 did not prevent inhibition of TNF alpha production by J-113863. The compound did not inhibit mouse TNF alpha in vitro, but did induce a trend towards increased TNF alpha release in cells from synovial membranes of rheumatoid arthritis patients.Conclusions and implications: CCR1 blockade improves the development of CIA, probably via inhibition of inflammatory cell recruitment. However, results from both CCR1-deficient mice and human synovial membranes suggest that, in some experimental settings, blocking CCR1 could enhance TNF production.

The synthesis and structure–activity relationships of piperidinylpyrrolopyridines as potent and selective H1 antagonists are discussed. It was found that the nature of the acid chain bonded to piperidine was a key feature for maintaining both the duration of action in vivo and lack of sedative properties.

A series of indolylpiperidinyl derivatives were prepared and evaluated for their activity as histamine H(1) antagonists. Structure-activity relationship studies were directed toward improving in vivo activity and pharmacokinetic profile of our first lead (1). Substitution of fluorine in position 6 on the indolyl ring led to higher in vivo activity in the inhibition of histamine-induced cutaneous vascular permeability assay but lower selectivity toward 5HT(2) receptor. Extensive optimization was carried out within this series and a number of histamine H(1) antagonists showing potency and long duration of action in vivo and low brain penetration or cardiotoxic potential were identified. Within this novel series, indolylpiperidines 15, 20, 48,51 and 52 exhibited a long half-life in rat and have been selected for further preclinical evaluation.

A series of 2-phenylpyran-4-ones were prepared and evaluated for their ability to inhibit cyclooxygenase-2 (COX-2). Extensive structure-activity relationship work was carried out within this series, and a number of potent and selective COX-2 inhibitors were identified. Compounds having a p-methylsulfone group at the 2-phenyl ring showed the best COX-2 inhibitory activity. The introduction of a substituted phenoxy ring at position 3 enhanced both the in vitro and in vivo activity within the series. A selected group of 3-phenoxypyran-4-ones exhibited excellent activity in an experimental model of pyresis. The in vivo antiinflammatory activity of these compounds was confirmed with the evaluation of their antiarthritic and analgesic effectiveness. Moreover, their pharmacokinetic profile in rats is compatible with a once a day administration by oral route in humans. Within this novel series, compounds 21, 31, 34, and 35 have been selected for further preclinical and clinical evaluation.

The mechanistic relationships between initiating stimulus, cellular source and sequence of chemokine expression, and leukocyte recruitment during inflammation are not clear. To study these relationships in an acute inflammatory process, we challenged a murine air pouch with carrageenan. A time-dependent increase in TNF-alpha, monocyte chemottractant protein-1 (MCP-1), macrophage-inflammatory protein-1alpha (MIP-1alpha), RANTES, KC, and MIP-2 was found in the exudates preceding cell recruitment, but displaying different kinetic profiles. Air pouches generated for 2, 6, or 9 days before initiating inflammation demonstrated a proportional increase in the number of cells lining the cavities. Two hours after carrageenan stimulation, the synthesis of TNF-alpha and all chemokines but RANTES increased in proportion to the lining cellularity, although no differences in infiltrating leukocytes were found, suggesting that the early source of these mediators is resident cells. To assess the contribution of neutrophils to chemokine synthesis at later time points, we used neutropenic animals. Neutrophil depletion caused a decrease in TNF-alpha (51%), KC (37%), MIP-1alpha (30%), and RANTES (57%) levels and a 2-fold increase in monocytes 4 h after challenge. No effect on MIP-2 and MCP-1 levels was observed. The selective blockade of CXCR2 or CCR1 inhibited neutrophil recruitment by 74% and 54%, respectively, without a significant inhibition of monocytes. A differential effect on TNF-alpha and MCP-1 levels was observed after these treatments, indicating that the two receptors did not subserve a mere redundant chemotactic role. Overall, our results suggest that chemokines synthesized by resident cells play an important role in the evolution of the inflammatory response.

A series of pyrazolo[3,4-d]pyridazinones and analogues, potentially useful as peripheral vasodilators, were synthesized and evaluated as inhibitors of PDE5 extracted from human platelets. Several of them showed IC50 values in the range 0.14-1.4 microM. A good activity and selectivity profile versus PDE6 was found for compound 11e (6-benzyl-3-methyl-1-isopropyl-4-phenylpyrazolo[3,4-d] pyridazin-7(6H)-one). Structure-activity relationship studies demonstrated the essential role played by the benzyl group at position-6 of the pyrazolopyridazine system. Other types of pyridazinones fused with five and six membered heterocycles (pyrrole, isoxazole, pyridine and dihydropyridine), as well as some open models were prepared and evaluated. Besides the pyrazole, the best fused systems proved to be isoxazole and pyridine.

A series of 3,4-diaryloxazolones were prepared and evaluated for their ability to inhibit cyclooxygenase-2 (COX-2). Extensive structure-activity relationship work was carried out within this series, and a number of potent and selective COX-2 inhibitors were identified. The replacement of the methyl sulfone group on the 4-phenyl ring by a sulfonamide moiety resulted in compounds with superior in vivo antiinflammatory properties. In the sulfonamide series, the introduction of a methyl group at the 5-position of the oxazolone ring gave rise to very COX-2-selective compounds but with decreased in vivo activity. Selected 3,4-diaryloxazolones exhibited excellent activities in experimental models of arthritis and hyperalgesia. The in vivo activity of these compounds was confirmed with the evaluation of their antipyretic effectiveness and their ability to inhibit migration of proinflammatory cells. As expected from their COX-2 selectivity, most of the active compounds lacked gastrointestinal toxicity in vivo in rats after a 4-day treatment of 100 mg/kg/day. Within this novel series, sulfonamides 9-11 have been selected for further preclinical evaluation.

The synthesis of a new family of benzyl derivatives of 2,1,3-benzo- and benzothieno[3,2-a]thiadiazine 2,2-dioxides was achieved. The biological data revealed the first heterocyclic family of compounds with PDE 7 inhibitory properties appearing to be a new objective for the treatment of T-cell-dependent disorders. The IC(50) values or percent inhibition values of the compounds against PDE 7 were calculated by testing them against human recombinant PDE 7 expressed in S. cerevisiae. In this expression system the only cyclic nucleotide hydrolyzing activity present in cell extracts corresponded to human PDE 7. Isoenzyme selectivity PDE 7 versus PDE 4 and PDE 3 was also measured. Considering simultaneously inhibition of the three different isoenzymes, monobenzyl derivatives 15 and 23 showed interesting PDE 7 potency (around 10 microM); although not statistically significant, a trend toward selectivity with respect to PDE 3 and PDE 4 was obtained. Benzothiadiazine 16, although less potent at PDE 7 (IC(50) = 25 microM), also showed a trend of selectivity toward PDE 3 and PDE 4. These compounds are considered the best leads for further optimization.

A novel series of 2,5-dihydropyrazolo[4,3-c]quinolin-3-ones has been prepared. These compounds showed good PDE 4 inhibitory activity and weak affinity for rolipram's binding site. They also exhibited a good anti-inflammatory profile without emetic side effects.

Almotriptan (3-[2-(dimethylamino)ethyl]-5-(pyrrolidin-1-ylsulfonylmethyl )-1H-indo le) has been studied in several models predictive of activity and selectivity at 5-HT receptors. Almotriptan showed low nanomolar affinity for the 5-HT(1B) and 5-HT(1D) receptors in several species, including the human, while affinity for 5-HT receptors other than 5-HT(1B/1D) was clearly less. Affinity for 5-HT(7) and 5-HT(1A) receptors was approximately 40 and 60 times lower than that for 5-HT(1B/1D) receptors, respectively. Almotriptan did not exhibit significant affinity for several non-5-HT receptors studied up to 100 microM. Almotriptan inhibited forskolin-stimulated cyclic AMP accumulation in HeLa cells transfected with 5-HT(1B) or 5-HT(1D) human receptors. In this model, almotriptan had the same efficacy as serotonin and an affinity in the low nanomolar range. It induced vasoconstriction in several vessels in which it was compared with sumatriptan. In isolated dog saphenous veins, almotriptan elicited concentration-dependent contractions with an EC(50) of 394 nM. In both these systems, almotriptan behaved as a full agonist. Infusion of almotriptan into the porcine meningeal vasculature induced vasoconstriction. In contrast, in the pig renal and rabbit mesenteric arteries, it had a very low maximal efficacy even at 100 microM, with similar results obtained in the rabbit renal artery. The results suggest that almotriptan is a potent and selective 5-HT(1B/1D) receptor agonist, with selectivity for the cranial vasculature as compared with peripheral vessels.