Evolución del consumo de lorazepam en un medio rural en la Región de Murcia (2012-2018) / Evolution of the consumption of lorazepam in a rural environment in the Region of Murcia (2012-2018)

Objetivo: Evaluar el consumo de lorazepam en la Región de Murcia, concretamente en el municipio de Mula, durante el periodo 2012-2018, consideran-do las variables edad y sexo.Método: Estudio descriptivo trasversal, donde se investiga el consumo de Benzodiacepinas en una población concreta durante el periodo 2012 – 2018. Las variables recogidas fueron el sexo, la edad y la Dosis Diaria Definida prescrita. Los datos corres-ponden a las dispensaciones de Lorazepam en las oficinas de farmacia del municipio de Mula, facilita-dos por la Dirección General de Asistencia Sanita-ria. Se calcularon las Dosis diaria por habitante y día por 1000 habitantes y se establecieron median-te mediana y rangos intercuartílicos p25 y p75 los grupos para posteriores comparaciones.Resultados: El consumo global durante el periodo estudiado aumento un 0,42%. En los hombres se incrementó un 21,4%, mientras que en las mujeres disminuyó un 7,5%. Sin embargo, en las mujeres el consumo se produce a dosis más elevadas, encon-trándose diferencias significativas en el consumo de lorazepam entre grupos al analizar por sexo. El análisis por edades mostró un aumento significa-tivo de consumo conforme aumentaba la edad de los pacientes. Conclusión: El consumo de benzodiacepinas es elevado a medida que avanza la edad, de manera más acuciante en las mujeres, pudiendo esto incidir sobre los efectos adversos asociados a este grupo de fármacos y presentando un importante proble-ma de salud pública.(AU)

Objective: To evaluate the consumption of loraz-epam in the Region of Murcia, specifically in the dis-trict of Mula, during the period 2012-2018, consider-ing age and sex variables.Method: Cross-sectional descriptive study, where the use of benzodiazepines in a specific popula-tion during the period 2012 - 2018 is investigated. The variables collected were sex, age and the prescribed Defined Daily Dose. The data corre-spond to the dispensations of Lorazepam in the pharmacy offices of the disctrict of Mula, provided by the Health Assistance General Directorate. Daily dose per inhabitant and per 1000 inhabitants were calculated and the groups median and interquar-tile ranges were established p25 and p75 for later comparisons.Results: Overall consumption over the period increased by 0.42%. In men it increased by 21.4%, while in women it decreased by 7.5%. However, in women, consumption was at higher doses, bet-wand significant differences were found in lora-zepam consumption een groups when analyzed by sex. The analysis by age showed a significant increase in consumption as the age of the patients increased.Conclusion: The consumption of benzodiazepines is high with increasing age, more so in women, and this may have an impact on the adverse effects associated with this group of drugs and present an important public health problem.(AU)

Evaluation of Risk Factors Associated to Prescription of Benzodiazepines and its Patterns in a Cohort of Patients from Mental Health: A Real World Study in Spain.

Purpose: we aimed 1) to evaluate the risk factors associated to the benzodiazepines intake; 2) to assess the impact about the use of long acting injectables antipsychotics (LAIs); 3) to assess the risk in severe and affective disorders and 4) to identify the prescription patterns of use in mental health in a cohort of patients from Spain. Methods: 735 outpatients from Mental Health were included. Demographic and clinical data were collected. In order to compare the use of benzodiazepines we calculated the daily dose equivalents (mg/day) to diazepam as standard. Results: The most commonly prescribed benzodiazepine was clonazepam (33%) and the mean daily dose of diazepam equivalents was 24.9 mg. It was higher in affective disorders (40.35 ± 3.36) and lower in patients using LAIs antipsychotics (17.50 ± 1.39; p = 0.001). Multivariate analysis showed that to be women (OR = 1.559, 95% CI = 1.059-2.295, p = 0.024), the use of drugs (OR = 1.671, 95% CI = 1.127-2.477, p = 0.011) and suffering any affective disorder (OR = 1.542, 95% CI = 1.355-1.826, p = 0.040) increased the risk of benzodiazepine intake. In contrast, the use of LAIs antipsychotics significantly reduced it versus oral antipsychotics (OR = 5.226, 95% CI = 3.185-8.575, p = 0.001). Conclusions: benzodiazepines are widely prescribed, mainly clonazepam followed by lorazepam and diazepam. Most of patients used at least one benzodiazepine and the mean daily intake was 25 mg diazepam equivalents. Therefore, benzodiazepines are extensively prescribed and used at higher doses than desirable. These, findings could be useful for clinicians and their practice.

Off-label use of second-generation antipsychotics in borderline personality disorder: a comparative real-world study among oral and long-acting injectables in Spain.

The aim of the present study was to evaluate the use of oral vs. long-acting injectables (LAIs) antipsychotics, as well as, to compare the effectiveness of different LAI antipsychotics [aripiprazole-1-month, paliperidone-1-month (PP1M), paliperidone-3-month (PP3M) and risperidone long-acting injectable (RLAI)] in patients diagnosed with borderline personality disorder (BPD), by evaluating the following clinical outcomes: (1) the number of hospital admissions; (2) the number of documented suicidal behaviour/attempts; and (3) the use of concomitant treatments, including benzodiazepines, oral antipsychotics and biperiden. We included a total of 116 patients diagnosed with BPD and treated with antipsychotic medication: 50 using a LAI antipsychotic formulation and 66 using the equivalent main oral antipsychotic. Patients treated with LAIs showed a decreased ratio of visits to emergency compared with the oral treatment group, and between LAIs, PP3M vs. aripiprazole-1-month group. Furthermore, patients treated with LAIs used lower number and dose of concomitant antipsychotics compared with patients treated with oral antipsychotics. Moreover, PP1M and PP3M used lower daily dose of diazepam equivalents compared with the aripiprazole-1-month and RLAI treatment groups. In conclusion, the use of LAIs may play a role in the management of BPD.

Evaluation of long-acting injectable antipsychotics with the corresponding oral formulation in a cohort of patients with schizophrenia: a real-world study in Spain.

To date, only a few studies compared some long-acting injectables (LAIs) antipsychotics showing similar symptom improvement, relapse rates and adherence to treatment. We evaluated the use of LAIs antipsychotics [aripiprazole-1-month (A1M); paliperidone-1-month and 3-month (PP1M and PP3M) and biweekly (2w)-LAIs] and their corresponding oral formulations through (1) the number of hospital re-admissions, (2) the number of documented suicidal behaviour/attempts and (3) the use of concomitant benzodiazepines, oral antipsychotics and biperiden. A total of 277 patients, ≥18 years old, were included if were treated with the corresponding oral or LAI antipsychotic during at least 12 months and were previously diagnosed with schizophrenia. Our results showed that LAIs associated significantly lower suicidal behaviour, reduced the number of hospital admissions, lower diazepam and haloperidol equivalents and mean daily dose of biperiden intake versus oral antipsychotics. Furthermore, significant differences were found between LAIs. Specifically, PP3M was associated to lower hospital admissions versus A1M; PP1M and PP3M lower doses of diazepam equivalents versus 2w-LAIs and finally, PP1M lower antipsychotic intake versus 2w-LAIs. In conclusion, LAIs improved clinical outcomes by reducing the need for concomitant treatments and hospital admissions over oral antipsychotics. PP1M and PP3M showed better outcomes versus A1M and biweekly LAIs.

Long-Acting Injectable Antipsychotics: Analysis of Prescription Patterns and Patient Characteristics in Mental Health from a Spanish Real-World Study.

BACKGROUND AND OBJECTIVE: Long-acting injectable antipsychotics (LAIs) have been widely studied in schizophrenia and evidence suggests that they could be also used for the treatment of bipolar and schizoaffective disorders. Nonetheless, there are no studies evaluating their role in other psychiatric disorders. We aimed to evaluate the use of the newest monthly and 3-monthly LAIs-aripiprazole once monthly, paliperidone 1- and 3-monthly (PP1M, PP3M)-against the 2-weekly LAIs, using the following clinical outcomes: (1) the number of hospital re-admissions, (2) the number of documented suicidal behaviors/attempts, and (3) the use of concomitant treatments, including benzodiazepines, oral antipsychotics, and biperiden. METHODS: A total of 431 patients were included who were treated with the corresponding LAI over at least 12 months and were previously diagnosed with a psychiatric disorder. Statistical analyses were performed using an ANCOVA model, Student's t test, and the Pearson's r test. RESULTS: Our results showed significantly decreased re-admissions using PP3M versus the bi-weekly LAIs and aripiprazole once monthly, while no significant differences were found in suicidal behavior. Furthermore, we found a significantly lower intake of benzodiazepines in PP1M and PP3M groups versus the bi-weekly and aripiprazole once-monthly groups. In addition, patients treated with PP1M and PP3M used a significantly lower dose of haloperidol equivalents versus the bi-weekly LAIs group. Finally, significantly higher doses of biperiden were used by the bi-weekly LAIs group. CONCLUSION: In conclusion, paliperidone LAIs reduced hospital re-admissions and, as aripiprazole once monthly, lowered concomitant psychiatric medication versus the bi-weekly LAIs. Further research and analysis of subgroups are needed; however, these findings might be useful for clinicians.

Phosphodiesterase PDE2 activity, increased by isoprenaline, does not reduce ß-adrenoceptor-mediated chronotropic and inotropic effects in rat heart.

Myocardial PDE2 activity increases in terminal human heart failure and after isoprenaline infusion in rat heart. PDE2 inhibitors do not potentiate the murine sinoatrial tachycardia produced by noradrenaline. We investigated whether isoprenaline infusion induces PDE2 to decrease the chronotropic and inotropic effects of catecholamines in rat heart. Sprague-Dawley rats were infused with isoprenaline (2.4 mg kg-1 day-1) for 3 days. We used spontaneously beating right atria, paced right ventricular strips and left ventricular papillary muscles. The effects of the PDE2 inhibitors EHNA (10 µM) and Bay 60-7550 (0.1-1 µM) were investigated on the cardiostimulation produced by noradrenaline (ICI118551 50 nM present to block ß2-adrenoceptors) and adrenaline (CGP20712A 300 nM present to block ß1-adrenoceptors). Hydrolysis of cAMP by PDE2 was measured by radioenzyme assay. Bay 60-7550 but not EHNA increased sinoatrial beating. A stable tachycardia elicited by noradrenaline (10 nM) or adrenaline (1 µM) was not increased by the PDE2 inhibitors. Isoprenaline infusion increased the hydrolytic PDE2 activity threefold in left ventricle, reduced the chronotropic and inotropic effects and potency of noradrenaline and abolished the effects of adrenaline. The potency of the catecholamines was not increased by the PDE2 inhibitors. Neither EHNA nor Bay 60-7550 potentiated the effects of the catecholamines. Rat PDE2 decreased basal sinoatrial beating but did not reduce the sinoatrial tachycardia or increases of ventricular force mediated through ß1- and ß2-adrenoceptors. The ß-adrenoceptor desensitization induced by the isoprenaline infusion was not reversed by the PDE2 inhibitors despite the increased hydrolysis of cAMP by PDE2.

Inhibitors of phosphodiesterases PDE2, PDE3, and PDE4 do not increase the sinoatrial tachycardia of noradrenaline and prostaglandin PGE1 in mice.

Phosphodiesterases PDE2, PDE3, and PDE4 are expressed in murine sinoatrial cells. PDE3 and/or PDE4 reduce heart rate but apparently do not influence the tachycardia mediated through sinoatrial ß1- and ß2-adrenoceptors despite the high content of sinoatrial cAMP. The function of PDE2 is, however, uncertain. Prostaglandin PGE1 elicits sinoatrial tachycardia through EP receptors, but the control by phosphodiesterases is unknown. We investigated on spontaneously beating right atria of mice the effects of the PDE2 inhibitors Bay 60-7550 and EHNA on basal beating and the tachycardia produced by noradrenaline (3 nM) and PGE1 (1 µM). Bay 60-7550 (1 µM), but not EHNA (10 µM), increased basal sinoatrial beating. EHNA also failed to produce tachycardia in the presence of the adenosine deaminase inhibitor 2'-deoxycoformycin (10 µM), remaining inconclusive whether PDE2 reduces basal sinoatrial beating. Rolipram (10 µM) and cilostamide (300 nM) caused moderate tachycardia. The tachycardia evoked by Bay 60-7550 was similar in the absence and presence of rolipram. Noradrenaline elicited stable tachycardia that was not increased by Bay 60-7550. A stable tachycardia caused by PGE1 was not increased by the inhibitors of PDE2, PDE3, and PDE4. Unlike PDE3 and PDE4 which reduce murine basal sinoatrial beating, a possible effect of PDE2 needs further research. The stable tachycardia produced by noradrenaline and PGE1, together with the lack potentiation by the inhibitors of PDE2, PDE3, and PDE4, suggests that cAMP generated at the receptor compartments is hardly hydrolyzed by these phophodiesterases. Evidence from human volunteers is consistent with this proposal.

Carvedilol induces greater control of ß2- than ß 1-adrenoceptor-mediated inotropic and lusitropic effects by PDE3, while PDE4 has no effect in human failing myocardium.

The ß-blockers carvedilol and metoprolol provide important therapeutic strategies for heart failure treatment. Therapy with metoprolol facilitates the control by phosphodiesterase PDE3, but not PDE4, of inotropic effects of catecholamines in human failing ventricle. However, it is not known whether carvedilol has the same effect. We investigated whether the PDE3-selective inhibitor cilostamide (0.3 µM) or PDE4-selective inhibitor rolipram (1 µM) modified the positive inotropic and lusitropic effects of catecholamines in ventricular myocardium of heart failure patients treated with carvedilol. Right ventricular trabeculae from explanted hearts of nine carvedilol-treated patients with terminal heart failure were paced to contract at 1 Hz. The effects of (-)-noradrenaline, mediated through ß1-adrenoceptors (ß2-adrenoceptors blocked with ICI118551), and (-)-adrenaline, mediated through ß2-adrenoceptors (ß1-adrenoceptors blocked with CGP20712A), were assessed in the absence and presence of the PDE inhibitors. The inotropic potency, estimated from -logEC50s, was unchanged for (-)-noradrenaline but decreased 16-fold for (-)-adrenaline in carvedilol-treated compared to non-ß-blocker-treated patients, consistent with the previously reported ß2-adrenoceptor-selectivity of carvedilol. Cilostamide caused 2- to 3-fold and 10- to 35-fold potentiations of the inotropic and lusitropic effects of (-)-noradrenaline and (-)-adrenaline, respectively, in trabeculae from carvedilol-treated patients. Rolipram did not affect the inotropic and lusitropic potencies of (-)-noradrenaline or (-)-adrenaline. Treatment of heart failure patients with carvedilol induces PDE3 to selectively control the positive inotropic and lusitropic effects mediated through ventricular ß2-adrenoceptors compared to ß1-adrenoceptors. The ß2-adrenoceptor-selectivity of carvedilol may provide protection against ß2-adrenoceptor-mediated ventricular overstimulation in PDE3 inhibitor-treated patients. PDE4 does not control ß1- and ß2-adrenoceptor-mediated inotropic and lusitropic effects in carvedilol-treated patients.

PDE3, but not PDE4, reduces ß1 - and ß2-adrenoceptor-mediated inotropic and lusitropic effects in failing ventricle from metoprolol-treated patients.

BACKGROUND AND PURPOSE: PDE3 and/or PDE4 control ventricular effects of catecholamines in several species but their relative effects in failing human ventricle are unknown. We investigated whether the PDE3-selective inhibitor cilostamide (0.3-1 µM) or PDE4 inhibitor rolipram (1-10 µM) modified the positive inotropic and lusitropic effects of catecholamines in human failing myocardium. EXPERIMENTAL APPROACH: Right and left ventricular trabeculae from freshly explanted hearts of 5 non-ß-blocker-treated and 15 metoprolol-treated patients with terminal heart failure were paced to contract at 1 Hz. The effects of (-)-noradrenaline, mediated through ß1 adrenoceptors (ß2 adrenoceptors blocked with ICI118551), and (-)-adrenaline, mediated through ß2 adrenoceptors (ß1 adrenoceptors blocked with CGP20712A), were assessed in the absence and presence of PDE inhibitors. Catecholamine potencies were estimated from -logEC50s. KEY RESULTS: Cilostamide did not significantly potentiate the inotropic effects of the catecholamines in non-ß-blocker-treated patients. Cilostamide caused greater potentiation (P = 0.037) of the positive inotropic effects of (-)-adrenaline (0.78 ± 0.12 log units) than (-)-noradrenaline (0.47 ± 0.12 log units) in metoprolol-treated patients. Lusitropic effects of the catecholamines were also potentiated by cilostamide. Rolipram did not affect the inotropic and lusitropic potencies of (-)-noradrenaline or (-)-adrenaline on right and left ventricular trabeculae from metoprolol-treated patients. CONCLUSIONS AND IMPLICATIONS: Metoprolol induces a control by PDE3 of ventricular effects mediated through both ß1 and ß2 adrenoceptors, thereby further reducing sympathetic cardiostimulation in patients with terminal heart failure. Concurrent therapy with a PDE3 blocker and metoprolol could conceivably facilitate cardiostimulation evoked by adrenaline through ß2 adrenoceptors. PDE4 does not appear to reduce inotropic and lusitropic effects of catecholamines in failing human ventricle.

Function of cardiac beta1- and beta2-adrenoceptors of newborn piglets: role of phosphodiesterases PDE3 and PDE4.

The structures of porcine and human beta(2)-adrenoceptors differ but the repercussions for porcine cardiac function are unknown. We investigated the function of porcine beta(2)-adrenoceptors in 3 cardiac regions, sinoatrial node, left atrium and right ventricle of newborn piglets. Both (-)-noradrenaline and (-)-adrenaline caused sinoatrial tachycardia: 60+/-10% and 62+/-7% of the maximum response (E(max)) to (-)-noradrenaline (-logEC(50)=9.0) and (-)-adrenaline (-logEC(50)=7.5) respectively, were resistant to antagonism by the beta(1)-selective CGP20712A (2-hydroxy-5-[2-[[2-hydroxy-3-[4-[1-methyl-4-(trifluoromethyl)-1H-imidazol-2-yl]phenoxy]propyl]amino]ethoxy]-benzamide) (300 nM) but antagonized by beta(2)-selective ICI118551 (erythro(+/-)-[1-(2,3-dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol) (50 nM), consistent with mediation through beta(2)-adrenoceptors. The phosphodiesterase3-selective inhibitor cilostamide and phosphodiesterase4-selective inhibitor rolipram did not affect catecholamine chronotropic potencies. Only small CGP20712A-resistant positive inotropic effects of (-)-adrenaline were detected in the left atria (13+/-2% of E(max)) and ventricular trabeculae (14+/-5% of E(max)). The atrial inotropic responses to (-)-noradrenaline and (-)-adrenaline faded; fades were prevented by rolipram but not cilostamide or concurrent cilostamide+rolipram respectively. (-)-Noradrenaline (ICI118551 present) increased left atrial cAMP levels through beta(1)-adrenoceptors that were markedly enhanced by rolipram but unaffected by cilostamide. Concurrent cilostamide+rolipram uncovered inotropic and cAMP responses to (-)-adrenaline (CGP20712A present). We conclude that sinoatrial beta(2)-adrenoceptors are more important than beta(1)-adrenoceptors in the mediation of tachycardia caused by both (-)-noradrenaline and (-)-adrenaline in the newborn piglet. beta(2)-adrenoceptors have only a minor role in the mediation of left atrial and ventricular inotropic effects of (-)-adrenaline. Catecholamine-evoked tachycardia is not controlled by PDE3 or PDE4. PDE4, but not PDE3, controls the atrial inotropic and cAMP beta(1)-adrenoceptor-mediated responses to (-)-noradrenaline. Both PDE3 and PDE4 blunt left atrial inotropic and cAMP responses to (-)-adrenaline through beta(2)-adrenoceptors.

Phosphodiesterases do not limit beta1-adrenoceptor-mediated sinoatrial tachycardia: evidence with PDE3 and PDE4 in rabbits and PDE1-5 in rats.

The mammalian heart expresses at least five phosphodiesterases (PDE1-5). Catecholamines produce surges of inotropically relevant cAMP through beta(1)-adrenoceptor stimulation. cAMP is mainly hydrolysed by PDE3 and/or PDE4 thereby blunting contractility. Basal sinoatrial beating rate in mouse, rat, piglet and rabbit sinoatrial cells is reduced by PDE3 and/or PDE4 through hydrolysis of cAMP. However, in rodents, the tachycardia elicited by catecholamines through production of cAMP by beta-adrenoceptor activation is not controlled by PDE3 and PDE4, despite a blunting effect of PDE3 or/and PDE4 on basal sinoatrial beating, but it is unknown whether PDE3 limits catecholamine-evoked tachycardia in the rabbit. Since rabbit sinoatrial cells are an important model for pacemaker research, we investigated whether the positive chronotropic effects of (-)-noradrenaline on spontaneously beating right atria of the rabbit are potentiated by inhibition of PDE3 with cilostamide (300 nM). We also studied the sinoatrial effects of the PDE4 inhibitor rolipram (10 microM) and its influence on the responses to (-)-noradrenaline. For comparison, we investigated the influence of cilostamide and rolipram on the positive inotropic responses to (-)-noradrenaline on rabbit left atria and right ventricular papillary muscles. Cilostamide and concurrent cilostamide + rolipram, but not rolipram alone, increased sinoatrial rate by 15% and 31% of the effect of (-)-isoprenaline (200 microM) but the PDE inhibitors did not significantly change the chronotropic potency of (-)-noradrenaline. In contrast in papillary muscle, the positive inotropic effects of (-)-noradrenaline were potentiated 2.4-, 2.6- and 44-fold by cilostamide, rolipram and concurrent cilostamide + rolipram, respectively. In left atrium, the positive inotropic effects of (-)-noradrenaline were marginally potentiated by cilostamide, as well as potentiated 2.7- and 32-fold by rolipram and by concurrent cilostamide and rolipram respectively. To compare the influence of PDE1-5 on basal sinoatrial rate and (-)-noradrenaline-evoked tachycardia, we investigated on rat right atria the effects of selective inhibitors. The PDE4 inhibitor rolipram and non-selective inhibitor isobutyl-methylxanthine caused tachycardia with -logEC(50)s of 7.2 and 5.0 and E(max) of 18% and 102% of (-)-isoprenaline, respectively. Rolipram did not change the chronotropic potency of (-)-noradrenaline. At high concentrations (10-30 microM), the PDE1, PDE3 and PDE5 inhibitors 8-methoxymethyl-3-isobutyl-1-methylxanthine, cilostamide and sildenafil, respectively, caused marginal tachycardia but did not significantly change the chronotropic potency of (-)-noradrenaline. The PDE2-selective inhibitor erythro-9-[2-hydroxy-3-nonyl]adenine caused marginal bradycardia at 30 microM and tended to reduce the chronotropic potency of (-)-noradrenaline. Rabbit PDE3 reduces basal sinoatrial rate. Although PDE4 only marginally reduces rate, under conditions of PDE3 inhibition, it further reduces sinoatrial rate. Both PDE3 and PDE4 control atrial and ventricular positive inotropic effects of (-)-noradrenaline. In contrast, neither PDE3 nor PDE4 limit the sinoatrial tachycardia induced by (-)-noradrenaline. In the rat, only PDE4, but not PDE1, PDE2, PDE3 and PDE5, reduces basal sinoatrial rate. None of the five rat PDEs limits the (-)-noradrenaline-evoked tachycardia. Taken together, these results confirm and expand evidence for our proposal that the cAMP-compartment modulating basal sinoatrial rate, controlled by PDE3 and/or PDE4, is different from the PDE-resistant cAMP compartment involved in beta(1)-adrenoceptor-mediated sinoatrial tachycardia.

Inotropy and L-type Ca2+ current, activated by beta1- and beta2-adrenoceptors, are differently controlled by phosphodiesterases 3 and 4 in rat heart.

BACKGROUND AND PURPOSE: beta(1)- and beta(2)-adrenoceptors coexist in rat heart but beta(2)-adrenoceptor-mediated inotropic effects are hardly detectable, possibly due to phosphodiesterase (PDE) activity. We investigated the influence of the PDE3 inhibitor cilostamide (300 nmol x L(-1)) and the PDE4 inhibitor rolipram (1 micromol x L(-1)) on the effects of (-)-catecholamines. EXPERIMENTAL APPROACH: Cardiostimulation evoked by (-)-noradrenaline (ICI118551 present) and (-)-adrenaline (CGP20712A present) through beta(1)- and beta(2)-adrenoceptors, respectively, was compared on sinoatrial beating rate, left atrial and ventricular contractile force in isolated tissues from Wistar rats. L-type Ca(2+)-current (I(Ca-L)) was assessed with whole-cell patch clamp. KEY RESULTS: Rolipram caused sinoatrial tachycardia. Cilostamide and rolipram did not enhance chronotropic potencies of (-)-noradrenaline and (-)-adrenaline. Rolipram but not cilostamide potentiated atrial and ventricular inotropic effects of (-)-noradrenaline. Cilostamide potentiated the ventricular effects of (-)-adrenaline but not of (-)-noradrenaline. Concurrent cilostamide + rolipram uncovered left atrial effects of (-)-adrenaline. Both rolipram and cilostamide augmented the (-)-noradrenaline (1 micromol x L(-1)) evoked increase in I(Ca-L). (-)-Adrenaline (10 micromol x L(-1)) increased I(Ca-L) only in the presence of cilostamide but not rolipram. CONCLUSIONS AND IMPLICATIONS: PDE4 blunts the beta(1)-adrenoceptor-mediated inotropic effects. PDE4 reduces basal sinoatrial rate in a compartment distinct from compartments controlled by beta(1)- and beta(2)-adrenoceptors. PDE3 and PDE4 jointly prevent left atrial beta(2)-adrenoceptor-mediated inotropy. Both PDE3 and PDE4 reduce I(Ca-L) responses through beta(1)-adrenoceptors but the PDE3 component is unrelated to inotropy. PDE3 blunts both ventricular inotropic and I(Ca-L) responses through beta(2)-adrenoceptors.

Ontogenic changes of the control by phosphodiesterase-3 and -4 of 5-HT responses in porcine heart and relevance to human atrial 5-HT(4) receptors.

BACKGROUND AND PURPOSE: Atrial inotropic responses to 5-HT mediated through 5-HT(4) receptors fade, presumably through phosphodiesterase (PDE) activity. We investigated the influence of a selective inhibitor of PDE3 (cilostamide) or of PDE4 (rolipram) on the fade of 5-HT responses in atrial muscle. EXPERIMENTAL APPROACH: 5-HT responses were compared, ex vivo, on sinoatrial beating rate of newborn piglets, porcine atrial and ventricular force, and human atrial force. cAMP levels were assessed in piglet atrium. KEY RESULTS: 5-HT-evoked sinoatrial tachycardia did not fade and was not potentiated by cilostamide (300 nmol.L(-1)) or rolipram (1 micromol.L(-1)). Inotropic responses to 5-HT faded in atria from piglets, adolescent pigs and humans. Cilostamide reduced atrial fade of 5-HT responses in adolescent pigs and humans but not in newborn piglets. Cilostamide disclosed 5-HT ventricular responses in newborn, but not adolescent pigs. Rolipram reduced fade of atrial 5-HT responses in newborn and adolescent pigs but not in humans. Concurrent cilostamide + rolipram abolished fade of 5-HT responses in porcine left atria and facilitated ventricular 5-HT responses, but did not reduce residual fade in human atrium in the presence of cilostamide. 5-HT-evoked increases in cAMP faded; fade was abolished by concurrent cilostamide + rolipram. CONCLUSIONS AND IMPLICATIONS: PDE3-induced control of porcine 5-HT responses differed in atrium and ventricle and changed with age. PDE3 and PDE4 jointly prevented fade of inotropic and cAMP responses to 5-HT in porcine atrium. Unlike porcine atria, only PDE3 induced fade of 5-HT responses in human atria.

Phosphodiesterases PDE3 and PDE4 jointly control the inotropic effects but not chronotropic effects of (-)-CGP12177 despite PDE4-evoked sinoatrial bradycardia in rat atrium.

Acting through a low-affinity site of the beta(1)-adrenoceptor (beta(1L)AR), CGP12177 causes sinoatrial tachycardia and positive inotropic effects in left atrium but not in the ventricle of the rat. However, inhibition of either PDE3 or PDE4 also uncovers positive inotropic effects of CGP12177 in ventricle, but whether these phosphodiesterases also control the atrial agonist effects of CGP12177 was unknown. We, therefore, investigated the effects of the PDE3-selective inhibitor cilostamide (300 nM) and PDE4 inhibitor rolipram (1 microM) on the (-)-CGP12177-evoked increases of sinoatrial beating rate and force of paced left atria of the rat. Rolipram (n = 8) increased basal sinoatrial rate by 27 +/- 5 bpm but cilostamide (n = 8) had no effect. The chronotropic potency of (-)-CGP12177 (-logEC(50)M = 7.5) was not changed by rolipram and cilostamide or their combination. (-)-CGP12177 increased left atrial force with intrinsic activity 0.25 compared to (-)-isoprenaline. Rolipram (n = 8) and cilostamide (n = 8) did not change basal force of left atria but concurrent rolipram + cilostamide (n = 8) increased force by 52 +/- 9% of the effect of 200 microM (-)-isoprenaline. Neither rolipram nor cilostamide affected the inotropic potency of (-)-CGP12177 (-logEC(50)M = 7.4) but concurrent rolipram + cilostamide caused potentiation (-logEC(50)M = 8.2) and converted (-)-CGP12177 into a full agonist compared to (-)-isoprenaline. Cyclic AMP appears to maintain sinoatrial rate and PDE4 elicits bradycardia through hydrolysis of cAMP in a compartment distinct from the beta(1L)AR-induced cAMP compartment through which (-)-CGP12177 causes tachycardia. In contrast to the (-)-CGP12177-evoked tachycardia, not controlled by PDE3 and PDE4, these isoenzymes jointly reduce (-)-CGP12177-evoked increases of left atrial contractility through beta(1L)AR.