Endothelium-dependent relaxation, cholesterol content and high energy metabolite balance in Watanabe hyperlipemic rabbit aorta

Functional and metabolic parameters of thoracic aorta from Watanabe heritable hyperlipemic (WHHL) rabbits (aged 11-14 months) were investigated in vitro. The aortic preparations, normally responsive to noradrenaline, showed a diminished response to the endothelium-dependent agent, acetylcholine, in comparison with control preparations from age-matched New Zealand rabbits (maximal relaxation: 33 +/- 4% in WHHL vs. 52 +/- 2% in controls: P less than 0.005). ATP relaxant effect (only partially endothelium-dependent) was unimpaired in WHHL aorta, and it was much higher than in controls (maximal response: 63 +/- 6% vs. 37 +/- 3%, respectively; P less than 0.005). The response to NaNO2, an endothelium-independent relaxant, was unchanged in WHHL aortas. Acetylcholine-induced response was found to be inversely related to the degree of total cholesterol infiltration in aorta (r = -0.62, P less than 0.05). No correlation was observed between either total serum cholesterol or triglycerides and ACh-induced response. Furthermore, the concentration of adenine nucleotides and nucleosides in the aortic tissue of WHHL rabbits was lower than in controls, indicating a loss of energy balance. The results indicate a functional damage induced by genetic hyperlipidemia on endothelium-dependent relaxation and an impairment of energy-rich phosphate metabolism of the aortic wall. The relationship between functional and metabolic parameters is not yet clarified.

Dual effect of ATP and UTP on rat atria: which types of receptors are involved?

The effects of adenine compounds and UTP were examined in electrically driven rat left atria. ATP, ADP, AMP, adenosine and UTP caused a dual inotropic effect: first a rapid decrease in contractility, and second an increase in contractile tension. alpha,beta-Methylene ATP caused an increase in contractile tension only, whereas 2-methylthio-ATP only induced a negative inotropic effect, 1,3-Dipropyl-8-cyclopentylxanthine inhibited the negative effects of ATP and adenosine, whereas 3,7-dimethyl-1-propargylxanthine did not influence the effects of ATP. Suramin but not reactive blue 2 antagonized the positive inotropism induced by ATP and alpha,beta-methylene ATP. Suramin also abolished the positive inotropic effect induced by UTP. These results demonstrate that ATP may induce negative inotropism directly by an action on A1-adenosine receptors and positive inotropism by an action on P2x-purinoceptors. UTP induces a positive inotropic effect mediated by suramin-sensitive receptors.

Does seawater acidification affect survival, growth and shell integrity in bivalve juveniles?

Anthropogenic emissions of carbon dioxide are leading to decreases in pH and changes in the carbonate chemistry of seawater. Ocean acidification may negatively affect the ability of marine organisms to produce calcareous structures while also influencing their physiological responses and growth. The aim of this study was to evaluate the effects of reduced pH on the survival, growth and shell integrity of juveniles of two marine bivalves from the Northern Adriatic sea: the Mediterranean mussel Mytilus galloprovincialis and the striped venus clam Chamelea gallina. An outdoor flow-through plant was set up and two pH levels (natural seawater pH as a control, pH 7.4 as the treatment) were tested in long-term experiments. Mortality was low throughout the first experiment for both mussels and clams, but a significant increase, which was sensibly higher in clams, was observed at the end of the experiment (6 months). Significant decreases in the live weight (-26%) and, surprisingly, in the shell length (-5%) were observed in treated clams, but not in mussels. In the controls of both species, no shell damage was ever recorded; in the treated mussels and clams, damage proceeded via different modes and to different extents. The severity of shell injuries was maximal in the mussels after just 3 months of exposure to a reduced pH, whereas it progressively increased in clams until the end of the experiment. In shells of both species, the damaged area increased throughout the experiment, peaking at 35% in mussels and 11% in clams. The shell thickness of the treated and control animals significantly decreased after 3 months in clams and after 6 months in mussels. In the second experiment (3 months), only juvenile mussels were exposed to a reduced pH. After 3 months, the mussels at a natural pH level or pH 7.4 did not differ in their survival, shell length or live weight. Conversely, shell damage was clearly visible in the treated mussels from the 1st month onward. Monitoring the chemistry of seawater carbonates always showed aragonite undersaturation at 7.4 pH, whereas calcite undersaturation occurred in only 37% of the measurements. The present study highlighted the contrasting effects of acidification in two bivalve species living in the same region, although not exactly in the same habitat.

P2X-purinoceptors in the heart: actions of ATP and UTP

Positive inotropic effects of ATP and UTP (1 microM - 1mM) were studied in isolated rat and guinea pig cardiac tissues. The potency order obtained was ATP>UTP in both species, suggesting possible interaction with P2X-purinoceptors. Binding studies using [(3)H]alpha,beta-methylene ATP as marker of P2X-purinoceptors revealed two receptor sites: one high-, the other low-affinity, in atria and ventricles from rat and guinea pig. Both ATP and UTP were found to bind high-affinity sites of [(3)H]alpha,beta-methylene ATP. The effects of various calcium inhibitors such as nifedipine, dantrolene, ryanodine and TMB-8 on positive inotropic effects induced by ATP and UTP were also studied. The results suggest that ATP and UTP may increase inotropism by interaction with P2X-purinoceptors by means of a calcium-dependent mechanism.

Effect of cholesterol-supplemented diet in heritable hyperlipidemic Yoshida rats: functional and morphological characterization of thoracic aorta

In this study we have considered the possibility of inducing vascular damage in Yoshida Pittsburg (YOS) rat, an inbred strain which has endogenous hyperlipidemia without vascular atherosclerotic damage. Cholesterol-enriched diet (4% cholesterol plus 1% cholic acid and 0.5% thiouracil) was administered to YOS rats, in order to induce atherogenesis. The results indicate that, despite significant increase in serum (about 2-fold) and aortic tissue cholesterol (about 6-fold), no morphological damage occurred. A reduction in acetylcholine-mediated relaxation (of about 37%) was observed. No inhibition of ATP- or sodium nitrite-induced relaxation, or of contraction induced by norepinephrine was seen. Serum triglyceride concentration did not vary after administration of a cholesterol-enriched diet. Our results suggest that in heritable hyperlipidemic Yoshida rat, after 2 months of cholesterol-enriched diet, despite increased serum cholesterol levels, no atheromatous plaque developed on the aortic wall. Impaired vascular function and reductions in the response to acetylcholine were related to changed endothelial cell function. Administration of a high cholesterol diet to YOS rat may represent a new model of mixed endogenous and exogenous hyperlipidemia that can resemble many human dislipidemic diseases and therefore may become a useful tool for the study of isolated endothelial dysfunction.

Aortic response to relaxing agents in Watanabe heritable hyperlipidemic (WHHL) rabbits of different age

Serum and aortic tissue cholesterol levels in parallel with aortic relaxation to endothelium-dependent and independent drugs were determined in Watanabe heritable hyperlipidemic (WHHL) rabbits in comparison with New Zealand (N.Z.) normocholesterolemic rabbits, aged 4-14 months. Serum cholesterol was elevated (626 +/- 99 mg/100 ml) in 4-6-month-old WHHL rabbits and significantly lower in 12-14-month-old animals (344 +/- 51 mg/100 ml). Cholesterol infiltration in thoracic aorta was high in young WHHL compared with N.Z. rabbits (0.88 +/- 0.3 mg/100 mg fresh tissue vs. 0.08 +/- 0.003 mg/100 mg, respectively) and it did not vary with age. In N.Z. rabbits, serum and aortic cholesterol levels were low from 4 to 14 months of age. The aortic relaxation to acetylcholine (0.03-3 microM) on EC50 noradrenaline precontracted rings was similar in 4-6-month-old WHHL and N.Z. rabbits of the same age. In WHHL rabbits, the relaxation to acetylcholine was significantly reduced in 7-11- (-35% at maximum) and in 12-14-month-old rabbits (-40% at maximum). In N.Z. rabbits the response to acetylcholine was not modified in the 3 age groups. The relaxation to ATP (30 microM to 3 mM) was reduced by age both in N.Z. and in WHHL rabbits, but in 12-14-month-old WHHL rabbits the maximal relaxing response was significantly more elevated than in age-matched N.Z. rabbits (50.1 +/- 2.5% vs. 35.1 +/- 3.2%, respectively). The aortic relaxation to NaNO2 (10 microM to 3 mM) was reduced by age both in N.Z. and in WHHL rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological characterization of a new purinergic receptor site in rabbit aorta

1. The pharmacological properties of a vasodilating purine-activated receptor that is not a P1 or P2-purinoceptor were investigated. 2. In rabbit isolated thoracic aorta precontracted with noradrenaline, ATP induced a 50% relaxation at 0.25 mM (EC 50%); in the absence of endothelium, EC 50% was 2.5 mM. 3. Adenosine induced a relaxation that was not different in both the presence and absence of endothelium, being EC 50% 0.48 and 0.37 mM, respectively. 4. The potent and selective P2y-purinoceptor agonist 2-methylthio-ATP (0.03-10 microM) induced a relaxation only in the presence of endothelium. 5. In de-endothelialized aorta, 8-phenyltheophilline (8-PT: P1 antagonist) and 3,7-dimethyl-1-propargylxanthine (DMPX: A2 antagonist) did not antagonize ATP- and adenosine-induced relaxation. 6. The present data support the presence of a new site of action for purines in rabbit isolated thoracic aorta. 7. A P3 subtype of purinoceptor, that may be identified in the hypothesized "nucleotide" receptor, is proposed.

Heparin: pharmacological potentials from atherosclerosis to asthma

1. Heparin belongs to a family of polysaccharide species, whose best known property is, undoubtedly, anticoagulant activity. However, heparin has many other pharmacological effects, particularly on the cardiovascular system. 2. The therapeutic use of chronically inhaled heparin has been suggested as prophylaxis in atherosclerosis. 3. Heparin, physiologically stored in mast cells of the respiratory system, has also been recently studied in the prevention of immunological and non-immunological asthmatic attacks. 4. Experimental findings and new hypotheses of heparin action in asthma and atherosclerosis are discussed.

Pharmacological characterization of endothelial cell nitric oxide synthase inhibitors in isolated rabbit aorta

Different receptors mediating the release of endothelium-derived nitric oxide (EDNO) have been identified at endothelial level. In the present study we aimed to characterise, on rabbit aorta by means of pharmacological tools, the generation of EDNO by receptors located on endothelial cell membrane (M3, P2u, P2y) and by direct activation of Ca2+ entry into the endothelial cell. Four vasodilating drugs were tested (acetylcholine, UTP, A23187 and 2-methyl-thio-ATP); they were active only if the endothelial layer was intact, suggesting that they act through endothelial receptors. The effect of different nitric oxide synthase (NOS) inhibitors (0.1 mM: L- and D-NAME, L-NMMA, L-NIO and 7-NI) was investigated on NO-mediated relaxation induced by the relaxants in vessels with intact endothelium. NOS inhibitors differently affected relaxation mediated by the vasoactive drugs in isolated rabbit aorta. Reversibility of the inhibition by using a fixed concentration of L-arginine (0.1 mM) was different depending on the relaxing drug and NOS-inhibitor. The data obtained support the coexistence in aortic vessel of more than one endothelial cell NOS isoform, each provided with different receptor coupling.

Endothelial nucleotide-mediated aorta relaxation in aged Watanabe heritable hyperlipidemic rabbits

We investigated the activity of muscarinic and purinergic endothelial receptors during atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbit aorta. Experiments were performed on isolated thoracic aorta from WHHL rabbits aged 1 and 2.5 years. The relaxant response to acetylcholine (ACh) was progressively reduced with aging, being almost completely abolished in 2.5-year-old rabbits. The relaxant effect of ATP was not affected by the P2-purinoceptor antagonist suramin, thus excluding any involvement of relaxant P2y purinoceptors in both considered ages. The pyrimidine UTP, acting on nucleotide (P2U) receptors, produced concentration-dependent relaxation in 1-year-old WHHL rabbit aorta only in the presence of endothelium; relaxation was reduced in older animals. In 1-year-old WHHL rabbits, the endothelium-dependent relaxant effect of UTP was not antagonized by suramin, but was by the inhibitors of nitric oxide (NO) effect, methylene blue (MB) and L-NG-nitroarginine methyl ester (L-NAME), suggesting involvement of NO in the UTP-mediated relaxation. Morphological data from electron microscopy observations indicated the presence of typical atherosclerotic lesions and extensive dystrophic changes in endothelial cells, gradually evolving at 1 and 2.5 years of age. The present data suggest that progressive atherosclerosis differentially affects the activity of endothelial receptors: The most precociously altered is the P2y-purinoceptor, followed by an impairment of the muscarinic and finally of the P2U-purinoceptor.

Characterization of in vitro relaxant mechanisms in erectile tissue from rabbits of different ages

In the present study we investigated the in vitro relaxant response of erectile tissue obtained from rabbits of different ages (3, 7 and 24 months) in order to detect the progression with age of cavernosal activity in response to substances acting via endothelium-dependent or -independent mechanisms. Noradrenaline induced a concentration-dependent contraction (0.1 microM-3 mM), with an increase in the contractility in the 24-month-old group. Acetylcholine produced a concentration-dependent relaxant effect in the three age groups, with a reduction of the maximal relaxant effect in older animals. ATP (10 microM-1 mM) and adenosine (10 microM-1 mM) induced a concentration-dependent relaxant effect that was higher in the older group. The presence of the NO2-synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) (0.1 mM) or of the P2-purinoceptor antagonist suramin did not affect ATP relaxation. Relaxation induced by sodium nitrite and nifedipine was reduced in older animals. In conclusion, aging selectively alters the in vitro responsiveness of rabbit erectile tissue. Purinergic system remains more active despite a decrease in the maximal endothelial cholinergic activity and the direct smooth muscle relaxant component.

Purine- and nucleotide-mediated relaxation of rabbit thoracic aorta: common and different sites of action

The mechanisms of the relaxant effect of purines and pyrimidines in New Zealand rabbit isolated aorta were investigated at endothelial and smooth muscle cell levels. Endothelium-mediated relaxation by ATP was only partially inhibited by the P2-purinoceptor antagonist suramin (0.1 mM). The pyrimidine UTP produced vasodilation by acting at the endothelial level and relaxation was not antagonized by suramin (0.1 mM). This effect was not mediated by P2 purinoceptors, indicating that UTP, like ATP to a certain extent, produces relaxation via an endothelium nucleotide (N) pyrimidinoceptor. ATP, ADP, AMP, adenosine, 5'-N-ethylcarboxamidoadenosine (NECA) and inosine were all active as relaxants on smooth muscle. The NECA relaxant effect was not antagonized by P1-purinoceptor antagonists 3,7-dimethyl-1-propargylxanthine (50 microM) or 1,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine (5 microM), excluding a P1-mediated effect. P2-related activity was excluded because adenosine-mediated relaxation was not antagonized by suramin (0.1 mM). UTP was ineffective as a relaxant at smooth muscle level, thus excluding the presence of muscular nucleotide (N) pyrimidinoceptor and suggesting a P3 purinoceptor. The rank order of potency of this muscle purinoceptor was NECA > adenosine > ATP approximately equal to ADP approximately equal to AMP approximately equal to inosine.

Pharmacological characterization of ATP receptors mediating vasodilation on isolated rabbit aorta

1. The effects of adenosine 5'-triphosphate (ATP), 2-methyl-thio-ATP and adenosine on rabbit aorta were examined in isolated preparations precontracted by noradrenaline, both in vessels where the endothelium was present and mechanically removed. 2. In the presence of endothelium, ATP (30 microM-3 mM) induced a relaxation that was reduced by removal of the endothelium. 3. The maximum endothelium-dependent relaxation of ATP was twice the maximum endothelial activity of the potent agonist at P2y-purinoceptors, 2-methyl-thio-ATP. 4. Adenosine which acts on P1 purinoceptors, induced a relaxant effect at 1 mM concentration, both in the vessels with and without endothelium. 5. It is concluded that relaxation by ATP is induced both via the endothelial P2y-purinoceptor and via a "nucleotide" receptor that is located on endothelium and on smooth muscle of rabbit aorta.

Receptor-mediated pathways of endothelium activity in experimental atherosclerosis

The pharmacological characterization of endothelial receptor activity during the progression of atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits was examined. The data presented show that progression of atherosclerosis affects endothelial receptor functionality in different ways. Nucleotide receptor activity is preserved for longer than that of the other endothelial receptors, i.e. muscarinic- and P2y-purinoceptors. This difference means that, in WHHL rabbit aorta, some mechanisms proposed to explain impaired endothelium-mediated relaxation in atherosclerosis must be excluded. It is therefore hypothesized that atherosclerosis in genetically hyperlipidemic animals selectively influences the receptorial arrangement of endothelium, as in other published examples of selective remodeling of receptors in arteries. Endothelial cell receptors may become a new interesting target for the development of drugs to treat atherosclerosis.

Phentolamine and hypoxia: modulation of contractility and alpha 1-adrenoceptors in isolated rat atria

The hypoxia-induced effects on the binding sites and affinity constant of adrenoceptors, in the presence and absence of phentolamine, were determined for atrial membranes of hearts from normal and genetically hyperlipidaemic Yoshida (YOS) rats. Atrial function was also measured during normoxia and hypoxia, in the presence and absence of phentolamine. Hypoxia increased alpha 1-adrenoceptor density in atrial membranes of normal rats (Bmax 10.6 to 26.7 fmoles/mg protein). Phentolamine prevented the increase in the Bmax of alpha 1-adrenoceptors and increased the equilibrium dissociation constant of these receptors (KD 0.17 to 0.53 nmol/l). Beta-adrenoceptors did not change during hypoxia, but the Bmax was slightly increased (26%) in the presence of phentolamine. Thus, the alpha 1/beta ratio increased from 0.40 in normoxia to 1.06 in hypoxia. In normoxic atria from YOS rats, the alpha 1/beta ratio was already elevated (0.86) in comparison to control rats (mainly due to a higher density of alpha 1-adrenoceptors in atrial membranes from YOS rats). This ratio was not modified by hypoxia (0.84), but decreased when phentolamine was present (0.30). Hypoxia reduced the force of contraction and increased diastolic tension of atria of normal rats, while the sinus rate was not significantly modified. Phentolamine abolished the increase in diastolic tension and reduced the negative effect of hypoxia on contractile force. In YOS rat atria, functional parameters were modified by hypoxia in a qualitatively similar way to that of normal rat atria.(ABSTRACT TRUNCATED AT 250 WORDS)

Resource consumption and costs of treating pain in patients affected by cancer in a district of northeast Italy

WHO declared that pain is a relevant problem in public health and that opioids are the gold standard therapy for the treatment of moderate to severe pain. The present retrospective, epidemiological, observational study is aimed to evaluate resource consumption therapy in patients treated with opioids and died with a diagnosis of cancer in Treviso, a district in northeast Italy. For the monetisation of resource consumed, the Italian National Health Service perspective was adopted. For each patient, resource monetized were drugs (opioids, NSAIDs and adjuvants), hospitalizations with cancer diagnosis, diagnostic examinations and laboratory tests. All databases were linked in order to obtain patient profile of resource consumption. A total of 935 patients were included in the study. The incident opioid prescribed were for 60% morphine, 37% fentanyl, and 2.5% buprenorphine. The average length of treatment with opioids was 105+/-73 days. Of the patients included in the study, 79% received an anti-inflammatory drug (traditional NSAIDs and/or COX2 inhibitors), while 21% of patients treated with opioids never had an anti-inflammatory reimbursed prescription during the observation period. The average length of anti-inflammatory treatment was 133+/-83 days. For the vast majority of prescribed anti-inflammatory drugs, the received daily dose (RDD) was widely greater then the defined daily dose (DDD) before and during treatment with opioids, while for opioids the RDD was in line with the revised DDD for fentanyl, and less than the DDD for morphine and buprenorphine. The total daily cost per patient before the first prescription of opioids was euro 11.36 while after the first prescription of opioids, it increased to euro 21.12. This study confirms the under utilization of opioids in Italy both in terms of dosages and length of therapy.

Effect of age on rabbit aortic responses to relaxant endothelium-dependent and endothelium-independent agents

The aim of this study was to evaluate the effects of aging on endothelium-dependent and endothelium-independent relaxation of rabbit thoracic aorta from New Zealand white rabbits aged 4-6 and 7-12 months. The contractile response to noradrenaline (NA) decreased with increasing age, but NA [EC50] did not vary significantly. Acetylcholine (Ach)-induced relaxation of aortic rings precontracted with NA [EC50] did not change significantly with increasing age. The relaxation induced by ATP of aortic rings, precontracted with NA [EC50], was significantly greater in young than in adult rabbits. This difference between young and adult animals became more evident in aortic rings deprived of endothelium: in adult animals, the ATP-induced relaxation of aortic rings with endothelium was significantly greater than in the rings without endothelium. The endothelium-independent relaxation by sodium nitrite (NaNO2) at lower concentrations was significantly greater in young than in adult rabbit aortic rings precontracted with NA [EC50]. Concluding, the age-induced changes in vascular response in male New Zealand white rabbits are related to an impaired mechanism at smooth muscle level.

Species-dependent effects of increasing hypoxia on functions and energy balance in isolated atria

1. The hypoxia-induced changes of contractile force, frequency and diastolic tension in isolated atria from guinea pig, rat and rabbit were studied together with tissue content of adenine nucleotides, creatine phosphate and lactic acid. 2. Increasing hypoxia induced a progressive reduction of contractility in guinea pig, rat and rabbit atria. Hypoxia also induced a progressive reduction of frequency in rat atria, whereas atrial rate decreased significantly only during drastic hypoxia in guinea pig and rabbit. In spontaneously beating atria, hypoxia increased diastolic tension only in rat. 3. After 30 min of drastic hypoxia, ATP decreased in guinea pig and rabbit but not in rat atria. Creatine phosphate decreased and lactic acid increased in all three species. 4. These data suggest that: (a) hypoxia-induced changes in atrial function and in metabolic content are species-dependent; (b) hypoxia-induced inhibition of atrial activity could represent protection aimed at saving energy.

Utilisation Pattern of Nonspecific Nonsteroidal Anti-Inflammatory Drugs and COX-2 Inhibitors in a Local Health Service Unit in Northeast Italy

BACKGROUND AND OBJECTIVE

Nonsteroidal anti-inflammatory drugs (NSAIDs) are prescribed widely in Italy. They include nonspecific NSAIDs (NS-NSAIDs) and the newly marketed cyclo-oxygenase (COX)-2 specific inhibitors (COXIBs) celecoxib and rofecoxib. The objective of this study was to describe the prescribing patterns for NS-NSAIDs and COXIBs in a local Italian area, analysing an administrative database.

PATIENTS AND METHODS

We extracted from the database information on subjects who had received at least one reimbursed prescription of an NSAID during the period between 1 January 2001 and 31 December 2001, including age, sex, patient identification code, Anatomical Therapeutic Chemical (ATC) classification system code, strength, formulation, number of packs prescribed, prescription date, and prescription of gastroprotective agents (GPAs) on the same day as the prescription of the NSAID. On the basis of the type of NSAID received, we divided the patients into five cohorts: oral NS-NSAIDs only during the observed year, injectable NS-NSAIDs only, celecoxib only, rofecoxib only, and a combination. For descriptive purposes, we defined three age groups: <40 years, 40-64 years, and >64 years. The duration of exposure to NSAID therapy was calculated using the most commonly prescribed dose for the different drugs. Subjects receiving >/=30 doses per year were defined as "regular users". Analyses included mean age, mean duration of exposure, percentage of regular users, and percentage of GPAs co-prescribed in the different cohorts.

RESULTS

NSAIDs were prescribed to 62 059 subjects from a resident population of 365 321 inhabitants; 43.8% received oral NS-NSAIDs only, 22.6% injectable NS-NSAIDs only, 7.2% celecoxib only, 5.2% rofecoxib only, and 22% different regimens of different types of NSAIDs. The mean duration of treatment increased with age in all cohorts; the mean age was 56 years in the NS-NSAID cohort, 61 years in the celecoxib cohort, and 62 years in the rofecoxib cohort (p = 0.01, COXIBs vs NS-NSAIDs). The mean duration of therapy was 11.4 days/year for injectable NS-NSAIDs, 43.8 days/year for rofecoxib, 50.5 days/year for oral NS-NSAIDs, and 53.7 days/year for celecoxib. Fifty-four percent of subjects in the oral NS-NSAID cohort were regular users versus 64% in the rofecoxib and 70% in the celecoxib groups (p = 0.001, COXIBs vs NS-NSAIDs). Co-prescription with GPAs was 9.5% for NS-NSAIDs, 8.4% for rofecoxib, and 7.7% for celecoxib.

CONCLUSIONS

Analysis of an administrative database in Italy showed a trend suggesting that COXIBs are prescribed to an older population and for a longer period of time than NS-NSAIDs, and that their use is less frequently associated with GPAs.

Protective role of heparin on in vitro functional aortic response in Watanabe heritable hyperlipidemic rabbits

The effects of prolonged in vivo heparin treatment upon vasomotor responses and content of cholesterol and energy related compounds were studied in isolated thoracic and abdominal aortas from Watanabe heritable hyperlipidemic (WHHL) rabbits. Unfractionated heparin was administered subcutaneously (2 mg/kg twice a day) to 3-month-old WHHL rabbits for a period of 6 months. A group of WHHL rabbits was treated with saline solution and considered as control. Aortic cholesterol infiltration and serum cholesterol were not significantly decreased by the prolonged heparin treatment. In heparin-treated WHHL rabbits, the in vitro aortic endothelium-dependent relaxation produced by acetylcholine or calcimycin (A 23187) was greater than in saline-treated WHHL group. ATP-induced aorta relaxation (endothelium-dependent and endothelium-independent) did not vary significantly in the two groups of WHHL rabbits, even after mechanical removal of endothelium. Also the noradrenaline-induced aorta contraction did not vary between the two groups of WHHL rabbits. No significant variation in energy-related compounds (except for ADP) was found in the aortic arch. These results suggest that heparin produces a protective effect on aortic tissue by acting mainly at endothelial level.

Pharmacological properties of MM-706, a new prostacyclin derivative

1. In human platelet-rich plasma, platelet aggregation induced in vitro by collagen (10 micrograms/ml) or thrombin (50 mU/ml) was dose-dependently inhibited by increasing concentrations of prostacyclin or of the new derivative (+/-)(5E)-13,14-didehydro-omega-hexanor(1-hydroxycyclo hexyl)-9a- carbaprostacyclin (MM-706) with an IC50 of 20-50 nM and 250-500 nM, respectively. In human platelets loaded with fura-2, the intracellular rise of [Ca2+] induced by thrombin was dose-dependently inhibited by MM-706 with an approximate IC50 of 100 microM. 2. In rabbit isolated femoral artery, MM-706 (10 nM-10 microM) was completely ineffective in relaxing the vessel, which was different to prostacyclin which was able to relax vessels at the same concentrations. 3. In in vitro guinea-pig ileum, prostacyclin produced a contractile effect in the concentration range 1 nM-10 microM, but the derivative MM-706 was ineffective at the same concentrations. Preventive addition of MM-706 did not inhibit prostacyclin contraction. 4. On isolated guinea-pig tracheal preparation, prostacyclin induced a concentration-dependent contraction but the new compound MM-706 showed a lower activity, in the concentration range 10 nM-10 microM. The activity of prostacyclin was not affected by the contemporary presence of MM-706. 5. It is concluded that MM-706 is a prostacyclin analogue with antiaggregating properties but without evident effects on smooth muscle of different regions.

Reduced L-arginine/lysine and L-arginine/aspartic acid ratios in aorta from Watanabe heritable hyperlipidaemic (WHHL) rabbit

L-Arginine is the endogenous source of nitric oxide in the endothelial cells of blood vessels. In thoracic aorta from Watanabe heritable hyperlipidaemic (WHHL) rabbits, the L-arginine/lysine and L-arginine/aspartic acid ratios were reduced in comparison to New Zealand rabbit aorta. This result indicates that a variation in aortic arginine/lysine or arginine/aspartic acid ratios could be related to the hyperlipidaemic status.

Antidepressants and the risk of arrhythmia in elderly affected by a previous cardiovascular disease: a real-life investigation from Italy

PURPOSE

The study aimed to fill existing knowledge gaps on the safety of antidepressant drugs (ADs) by estimating the risk of hospitalization for arrhythmia associated with use of selective serotonin reuptake inhibitors (SSRIs) and newer atypical ADs (NAAs) among elderly with previous cardiovascular (CV) events.

METHODS

The cohort was composed by 199,569 individuals aged ≥ 65 years from five Italian healthcare territorial units who were discharged for cardiovascular outcomes in the years 2008-2010. The 17,277 patients who experienced hospital admission for arrhythmia during follow-up were included as cases. Odds of current ADs use among cases (i.e., 14 days before hospital admission) was compared with (i) odds of current use of 1:5 matched controls (between-patients case-control) and with (ii) odds of previous use during 1:5 matched control periods (within-patient case-crossover). The risk of arrhythmia associated with ADs current use was modelled fitting a conditional logistic regression. A set of sensitivity analyses was performed to account for sources of systematic uncertainty.

RESULTS

Current users of SSRIs and NAAs were at increased risk of arrhythmia with case-control odds ratios (OR) of 1.37 (95% confidence interval, CI 1.18 to 1.58) and 1.41 (1.16 to 1.71) and case-crossover OR of 1.48 (1.20 to 1.81) and 1.72 (1.31 to 2.27). An increased risk of arrhythmia was associated with current use of trazodone (NAA) consistently in case-control and case-crossover designs.

CONCLUSIONS

Evidence that current use of SSRIs and NAAs is associated to an increased risk of arrhythmia among elderly with CV disease was consistently supplied by two observational approaches.

Benefit of statins in daily practice? A six-year retrospective observational study

This observational retrospective study analysed the association of adherence to statins with the achievement of a target total cholesterol level (CL, <200mg/dl), and any association of adherence with the time to first hospital admission for coronary event in hypercholesterolemic patients treated with statins, in one Italian Local Health Authority between 1998 and 2003. The study population consisted of 3516 patients who were prescribed statins and for whom full cholesterol results were available. After three months of treatment, there were significant reductions in CL (p<0.001) in the three treatment groups stratified by adherence (good adherents -24%, poor adherents -22%, and nonadherents -14%). Patients more likely to achieve the target CL were older, male and more adherent to the statins. The risk of first hospitalization was associated positively with increased age and male gender. Patients with co-treatments were more likely to be hospitalized. Surprisingly, better adherence to statin treatment increased the risk of hospitalization.

Chronic treatment with cyclosporine A in New Zealand rabbit: aortic and erectile tissue alterations

Transplanted patients frequently present erectile impotence. In order to test any interference by cyclosporine A (CsA), which is commonly used in the post-transplantation management, we investigated the in vitro contractile and relaxant responses of corpus cavernosum and aorta from rabbits chronically treated with CsA. Male New Zealand White rabbits 6 months of age were treated with CsA (25 mg/kg per day s.c.) or solvent (corn oil) for 3 weeks. Descending thoracic aorta and erectile tissue were studied in vitro at the end of treatment. Isometric tension was recorded. In thoracic aorta, noradrenaline (0.1-30 mM) induced a concentration-dependent contraction with no difference between the two groups. Acetylcholine (30 nM-3 mM) produced relaxation (52 +/- 4% at 1 mM) that was significantly reduced in comparison to controls (67 +/- 4%, P < 0.05). ATP (3-10 mM) relaxation was not significantly different (maximal 78 +/- 10% and 62 +/- 12% in CsA-treated and controls). The relaxation produced by sodium nitrite was reduced in CsA-treated rabbits (at 10 mM and 0.1 mM concentrations). In erectile tissue, no significant variation in the response of isolated erectile tissue to the above drugs was observed between CsA-treated and control animals. These data indicate that chronic treatment with CsA in rabbits, despite alteration of the in vitro response of thoracic aorta, does not directly influence the function of penile tissue with relaxants.