RESUMEN
OBJECTIVE: To review the role of diltiazem in treating and preventing a group of cardiovascular diseases, including painful and silent cardiac ischemia, stroke, nonfatal myocardial infarction and sudden cardiac death, by modulating certain physiological causes that they appear to share. DATA SOURCES: A MEDLINE search was conducted for all clinical articles on the use of diltiazem for hypertension and coronary artery disease. When clinical data were not available, basic research findings were reviewed. DATA EXTRACTION AND SYNTHESIS: Because many cardiovascular events show a marked daily periodicity--which appears to coincide with circadian peaks in the ability of platelets to aggregate, sympathetic activity, coronary tone, blood pressure, heart rate and hematocrit, and a trough in fibrinolytic activity--the impact of diltizazem on these physiological changes was assessed. CONCLUSIONS: Diltiazem influences many of these events by increasing myocardial bloodflow, and reducing myocardial oxygen demand and cardiac workload. However, it differs from other calcium antagonists in its mild negative inotropic and moderate negative dromotropic effects, without apparent stimulation of cardiac performance or contractility. In addition, it inhibits platelet aggregation, decreases catecholamine release, diminishes coronary tone and blocks the vasoconstrictive actions of endothelin-1. This appears to translate into a beneficial effect on ischemia, thrombolysis, arrhythmias, infarct parameters, atherosclerosis and hypertension. Diltiazem has a relatively favourable safety and tolerability profile, and is available in a once-daily dosage form. The most common adverse effects are related to vasodilation (eg, edema and headache), and the most frequent serious adverse event is atrioventricular block, which occurs rarely. In summary, diltiazem appears to be well suited to preventing the first occurrence of cardiovascular events and may even have a role in preventing certain types of secondary events. The data accumulated so far indicate the need for a large scale random clinical trial addressing these outcomes.
Asunto(s)
Arteriosclerosis/tratamiento farmacológico , Enfermedad Coronaria/tratamiento farmacológico , Diltiazem/uso terapéutico , Hipertensión/tratamiento farmacológico , Isquemia Miocárdica/tratamiento farmacológico , Arritmias Cardíacas/tratamiento farmacológico , HumanosRESUMEN
Under the reference-based pricing (RBP) policy, British Columbia will fund drug therapies based on the cost of the 'gold standard' therapy that meets the needs of the majority of patients with a specific condition. Hence, Pharmacare will pay for the lowest cost drug within a cluster of related but different drugs, regardless of the indication. When evaluating the impact of drugs on health care expenditure, one must consider that their costs are more than offset by the clinical and economic benefits they provide. Pharmaceutical expenditure accounts for a small proportion of health care expenditure and should be viewed as an essential and interactive component in the global health care budget rather than as an independent constituent. In that respect, insight should be gained from many countries in which RBP has been implemented A wealth of data converge to the same conclusion: price controls and restricted access to drugs do not reduce prescription drug expenditures but actually increase health care costs. Furthermore, cost containment being the main issue behind RBP in British Columbia, the contentious issue of therapeutic substitution has not been taken fully into consideration, nor has its impact on the quality of care of the patient. The case of diltiazem once-a-day versus diltiazem tablets for hypertensive and angina patients illustrates the important considerations that must be taken into account in writing the overall financial equation that drives the implementation of the RBP policy. If pharmacotherapy is to be an appropriate treatment to attain optimal cost effective health care, its benefit can only be optimized with a strategy that entails the right therapy, for the right patient, in the right dosage form and at the right time. Accordingly, RBP in British Columbia should be analyzed in light of patient welfare and appropriate use of collective resources.
Asunto(s)
Antihipertensivos/economía , Fármacos Cardiovasculares/economía , Costos de los Medicamentos/tendencias , Honorarios por Prescripción de Medicamentos/tendencias , Angina de Pecho/tratamiento farmacológico , Antihipertensivos/administración & dosificación , Colombia Británica , Fármacos Cardiovasculares/administración & dosificación , Control de Costos/métodos , Diltiazem/administración & dosificación , Diltiazem/economía , Esquema de Medicación , Medicamentos Genéricos/economía , Humanos , Hipertensión/tratamiento farmacológico , Cooperación del Paciente , Calidad de la Atención de SaludRESUMEN
The antihypertensive effects of once-daily diltiazem CD over a 24 hour period were compared with twice-daily diltiazem SR in 95 patients with mild to moderate hypertension using ambulatory blood pressure monitoring. This trial was designed as a multicenter, double-blind, parallel-group study. Following a 2 to 4 week placebo run-in period, diltiazem was administered as once-daily CD or twice-daily SR, starting with 180 mg daily and increasing to a maximum of 360 mg daily, to achieve a seated diastolic blood pressure goal of < or = 90 mmHg as measured by cuff between 08:00 and 10:00 in the morning. Following drug titration, patients received a maintenance dose of diltiazem for an additional 6 week follow-up phase. Twenty-four hour ambulatory blood pressure monitoring recordings were obtained at the end of the placebo, titration, and maintenance phases. Both diltiazem CD and diltiazem SR significantly reduced both systolic and diastolic blood pressure over the 24 hour day and maintained a normal circadian pattern. As well, treatment with once-a-day diltiazem CD significantly decreased the slope of the early morning rise of diastolic and mean blood pressure. Thus, diltiazem CD is as effective as diltiazem SR in lowering diastolic blood pressure over a 24 hour period and has the advantage of a once-daily formulation.
Asunto(s)
Antihipertensivos/administración & dosificación , Monitoreo Ambulatorio de la Presión Arterial , Diltiazem/administración & dosificación , Hipertensión/tratamiento farmacológico , Adolescente , Adulto , Anciano , Ritmo Circadiano , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The maintenance of angina control was assessed in this multicenter (three sites), randomized, double-blind, parallel-group study. Patients with stable angina pectoris receiving twice-daily sustained-release (SR) diltiazem were switched to equivalent doses of once-daily controlled-delivery (CD) diltiazem or to diltiazem SR. Patients who were switched from diltiazem SR to diltiazem CD (n = 28) experienced a 5% increase in time to termination (p = 0.0004) on the exercise tolerance test (ETT), as well as an 8% improvement in time to onset of angina (p < 0.0001) on the ETT. A similar trend was observed in patients randomized to diltiazem SR (n = 7), which suggested a training effect, and, therefore, equal efficacy between diltiazem SR and diltiazem CD. During exercise testing in the diltiazem SR baseline phase, 77% of the patients did not experience angina, whereas 60% of the patients did not experience ST-segment depression. Following transfer to diltiazem CD, 79 and 61% of patients, respectively, remained angina- and ST-segment depression free. No significant changes in the number of angina attacks, nitroglycerin use, or any hemodynamic-related parameters were observed following transfer to diltiazem CD. Eleven percent of the patients receiving diltiazem CD experienced treatment-related adverse events, which were limited to headache and abdominal pain; these adverse events did not lead to discontinuation of treatment. These findings suggest that patients whose angina is controlled with twice-daily diltiazem SR can be safely and effectively switched to an equivalent daily dose of the once-daily diltiazem CD.
Asunto(s)
Angina de Pecho/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/uso terapéutico , Diltiazem/uso terapéutico , Anciano , Presión Sanguínea/efectos de los fármacos , Bloqueadores de los Canales de Calcio/administración & dosificación , Bloqueadores de los Canales de Calcio/farmacología , Preparaciones de Acción Retardada , Diltiazem/administración & dosificación , Diltiazem/farmacología , Método Doble Ciego , Esquema de Medicación , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Nitroglicerina/administración & dosificación , Vasodilatadores/administración & dosificaciónRESUMEN
The efficacy and safety of optimally titrated once-daily (CD) and twice-daily (SR) diltiazem were compared in 111 patients with mild to moderate systemic hypertension [seated diastolic blood pressure (DBP) > or = 95 mmHg and < or = 114 mmHg] in a multicenter, randomized, double-blind, placebo run-in, parallel-group trial. Following a 4 week washout and placebo-controlled run-in period, patients were randomized to receive diltiazem CD 180 mg and matching placebo (n = 54), or diltiazem SR 90 mg bid (n = 57). Total daily doses were titrated from 180 mg to 360 mg to achieve a goal of seated DBP < 90 mmHg during a 6 week titration period. The patients continued to receive their optimal dose for a 6 week follow-up period. Ninety-six (96) patients (diltiazem CD: 47, diltiazem SR: 49) completed the study protocol, with 60% of the diltiazem CD and 55% of the diltiazem SR patients achieving the goal of seated DBP of < 90 mmHg (p = 0.685). Although significant decreases occurred in seated and standing measurements of diastolic and systolic BP and heart rate with treatment in both groups, there were no significant differences between treatment groups. Both medications were well tolerated, with a similar frequency of adverse effects [diltiazem CD: 24/54 (37%) patients; diltiazem SR: 24/57 (42.1%) patients] with the most frequently reported adverse effects being headache and edema.
Asunto(s)
Antihipertensivos/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Bloqueadores de los Canales de Calcio/administración & dosificación , Diltiazem/administración & dosificación , Hipertensión/tratamiento farmacológico , Adolescente , Adulto , Anciano , Análisis de Varianza , Antihipertensivos/efectos adversos , Antihipertensivos/farmacología , Bloqueadores de los Canales de Calcio/efectos adversos , Bloqueadores de los Canales de Calcio/farmacología , Diltiazem/efectos adversos , Diltiazem/farmacología , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , FumarRESUMEN
Controlled-delivery once-daily diltiazem (qd), 180 mg and 360 mg, was assessed in two multicenter, randomized, double-blind, placebo-controlled trials using a 3 x 3 Latin square design. Both studies compared the controlled-delivery dosage form to the same total daily dose of immediate-release diltiazem administered three times daily (tid) and to placebo. The primary measure of efficacy was the time to termination of the exercise tolerance test (ETT) at 2, 8, and 24 hours after the morning dose. There were no significant differences in time to ETT termination between the qd and tid formulations at any time, except at 24 hours with 180 mg qd versus 60 mg tid. The comparison to placebo showed that diltiazem 180 mg qd, 360 mg qd, and 120 mg tid significantly lengthened the time to ETT termination (p < 0.05) at all time points, while diltiazem 60 mg tid did not differ from placebo at any time point. The qd formulation also increased the time to 1-mm ST-segment depression and reduced the number of angina attacks and the amount of nitroglycerin used when compared to placebo. No new or unusual adverse events were noted. Diltiazem controlled-release capsules administered once daily are safe and effective for the treatment of patients with chronic stable angina.
Asunto(s)
Angina de Pecho/tratamiento farmacológico , Diltiazem/uso terapéutico , Anciano , Análisis de Varianza , Presión Sanguínea/efectos de los fármacos , Cápsulas , Preparaciones de Acción Retardada , Diltiazem/administración & dosificación , Diltiazem/farmacología , Método Doble Ciego , Quimioterapia Combinada , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Nitroglicerina/administración & dosificación , Nitroglicerina/farmacología , Nitroglicerina/uso terapéutico , Comprimidos , Equivalencia TerapéuticaRESUMEN
The 3-month efficacy and safety of a once-daily controlled formulation of diltiazem (180 to 360 mg/day) were assessed in a study of 54 patients with angina pectoris. This multicenter study was a nonrandomized, placebo run-in, open-label, 3-month trial followed by a 1-week, double-blind, randomized period during which most patients (89%) received placebo. There were only minimal changes in the time to termination (mean change +/- SEM -5.8 +/- 9.6 seconds), time to onset of angina (10.5 +/- 12.2 seconds), and the time to 1 mm ST-segment depression (2.9 +/- 12.5 seconds) from the end of the titration phase to the end of the open-label study. There were, however, statistically significant differences between the end of the 3-month treatment phase and the end of the 1-week randomized placebo phase for those 3 efficacy parameters (-37.3 +/- 11.2, -58.6 +/- 13.6, and -45.6 +/- 16.4 seconds, respectively). Diltiazem significantly decreased the frequency of anginal attacks and nitroglycerin use at the end of the 3-month treatment phase compared with results at the end of the randomized double-blind placebo phase. No new or unusual adverse events were reported during treatment. The present results suggest that there is no loss of efficacy of once-a-day diltiazem when administered for a long period to patients with chronic stable angina pectoris.
Asunto(s)
Angina de Pecho/tratamiento farmacológico , Diltiazem/uso terapéutico , Anciano , Enfermedad Crónica , Diltiazem/administración & dosificación , Diltiazem/efectos adversos , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
In a multicenter study, 61 patients, 18-70 years of age, with mild-to-moderate hypertension [diastolic blood pressure (DBP) 95/114] completed a 28-week treatment. After initial placebo washout, patients were randomly allocated either to diltiazem or hydrochlorothiazide/triamterene. At the end of 12 weeks, the patients continued on the same medication if their goal blood pressure achieved (DBP less than 90; or 10 mm Hg below baseline). If not, the alternate agent was added (either diltiazem + hydrochlorothiazide/triamterene or hydrochlorothiazide/triamterene + diltiazem). At the end of 28 weeks, the intent-to-treat analysis showed that 90% on diltiazem alone, 73.7% on hydrochlorothiazide/triamterene alone, 71.4% on (diltiazem + hydrochlorothiazide/triamterene), and 57.1% on (hydrochlorothiazide/triamterene + diltiazem) achieved goal BP. End point mean values of BP and heart rate after adjusting for sex, baseline values, age, and weight showed no significant difference between groups. Forty-six percent on hydrochlorothiazide/triamterene alone and 24% on diltiazem alone reported one or more adverse events, possibly related to study medication. Patients with diltiazem as the first choice had better BP control than those on hydrochlorothiazide/triamterene alone (81.5% vs. 69.7%). Furthermore, among non-goal achievers at week 12, there was a greater response in the group when hydrochlorothiazide/triamterene was added to diltiazem than when diltiazem was added to hydrochlorothiazide/triamterene. This study suggests that in mild-to-moderate hypertension, diltiazem is better than hydrochlorothiazide/triamterene as first line therapy.
Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Diuréticos/uso terapéutico , Hipertensión/tratamiento farmacológico , Potasio/metabolismo , Adolescente , Adulto , Anciano , Diltiazem/efectos adversos , Diltiazem/uso terapéutico , Método Doble Ciego , Esquema de Medicación , Quimioterapia Combinada , Femenino , Humanos , Hidroclorotiazida/efectos adversos , Hidroclorotiazida/uso terapéutico , Masculino , Persona de Mediana Edad , Método Simple Ciego , Factores de Tiempo , Triantereno/efectos adversos , Triantereno/uso terapéuticoRESUMEN
Adenylate cyclase activity and its hormonal stimulation were measured in endometrial tissue, and sex steroid levels were quantified in uterine tissue collected from pregnant and estrous rabbits. The tissues from pregnant animals were separated into implantation (ES) and interimplantation (IES) sites. Adenylate cyclase activity was measured in broken cell preparations by enzymatic conversion of alpha-32P-adenosine triphosphate (ATP) into 32P-cyclic adenosine 3', 5'-monophosphate using Mg2(+)-ATP as a substrate. The activity was measured with no addition (basal) and after stimulation with guanosine triphosphate (GTP), NaF, or increasing doses (1 nM to 100 microM) of isoproterenol (ISO) and prostaglandin E2 (PGE2). The presence of GTP was necessary to observe a stimulation by ISO and PGE2. During pregnancy, adenylate cyclase activity was reduced compared to activity at estrus on Day 6.5 (IES and ES) and on Day 9 (IES); however, it reached its highest level at ES (Day 9). The regulation of isoproterenol response followed a similar pattern. Dose responses to PGE2 were markedly affected by physiological status. The response was higher during pregnancy than at estrus, and response (percent of GTP), as well as sensitivity, was higher in IES than in ES on Day 6.5 and even greater on Day 9. The levels of estradiol (E2) were reduced during pregnancy, but comparable in ES and IES; however, progesterone (P) levels were reduced in ES, and the E2/P ratio was significantly higher (p less than 0.01) in ES (15 +/- 1, 17 +/- 2) than in IES (8 +/- 1, 6 +/- 0.8) on Days 6.5 and 9, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Adenilil Ciclasas/metabolismo , Dinoprostona/farmacología , Endometrio/enzimología , Estro/metabolismo , Isoproterenol/farmacología , Preñez/metabolismo , Animales , Endometrio/análisis , Endometrio/efectos de los fármacos , Estradiol/análisis , Femenino , Embarazo , Preñez/efectos de los fármacos , Progesterona/análisis , ConejosRESUMEN
Adenylate cyclase activity was measured in broken cell preparations of whole endometrial tissue from rabbits on Days 0, 1, 6.5, 9 and 15 of pseudopregnancy and in endometrial epithelial and stromal cells on Days 1 and 6.5 to assess the specific response of individual cell types. In dispersed cells, adenylate cyclase activity was higher (P less than 0.01) in stromal than in epithelial cells and reduced on Day 6.5 compared to Day 1 in both cell types. The response of adenylate cyclase to isoproterenol appeared more important relative to the PGE-2 response in epithelial than in stromal cells and strongly reduced in the former on Day 6.5. In endometrium, the overall adenylate cyclase activity was increased significantly on Day 1 of pseudopregnancy compared to Day 0 (oestrus), only 18 h after injection of hCG. On the following days, the activity decreased progressively on Days 6.5 and 9 and exhibited a recovery on Day 15. Adenylate cyclase response to isoproterenol (% over GTP) was comparable on Days 0, 1 and 6.5, abolished on Day 9 and recovered on Day 15. Maximal response to PGE-2 (% over GTP) was observed on Day 6.5, at the time of implantation, maintained on Day 9 and reduced on Day 15 towards the low levels measured in oestrus and Day 1 of pseudopregnancy. Our results demonstrate a dramatic alteration of adenylate cyclase activity in rabbit endometrium during pseudopregnancy. It suggests a possible involvement of catecholamines and prostaglandin E-2 in the regulation of endometrial receptivity through a cAMP-mediated process.
Asunto(s)
Adenilil Ciclasas/metabolismo , Endometrio/enzimología , Animales , Células Cultivadas , Dinoprostona/farmacología , Endometrio/efectos de los fármacos , Femenino , Guanosina Trifosfato/farmacología , Isoproterenol/farmacología , Seudoembarazo/enzimología , ConejosRESUMEN
The effect of pseudopregnancy (PSPG; days: 0 (estrus), 1, 6.5, 9 and 15) and pregnancy (PG; days: 6.5, 9 and 15) on adenylate cyclase (AC) activity was verified in rabbit myometrium. During PSPG, there was a time related decline in basal activity from 71 +/- 16.2 (D 0) to 13.1 +/- 1.6 (PSPG-D9) pmoles cAMP formed/mg prot-min. Stimulation of the enzyme by GTP, Isoproterenol (ISO), Prostaglandin E2 (PGE2) or Sodium Fluoride (NaF) followed a similar pattern. AC activity was compared in myometrial tissues of pregnant animals (PG) separated into embryonic (ES) and interembryonic (IES) sites. On days 6.5 and 9, AC activity measured in tissues from PG rabbits (ES and IES) was always higher than that found in tissues from PSPG animals on corresponding days. On day 6.5, AC activity was slightly higher (p less than 0.01) in ES than in IES. This was confirmed on day 9 where basal as well as GTP, ISO and PGE2 stimulated activities were higher in ES than in IES (p less than 0.001). Dose response to ISO, expressed as % of GTP, were similar on D0, 1, 6.5 and 15 of PSPG. However, on day 9, there was a striking diminution in response reflected by a lower stimulation at suboptimal dose (0.1 microM; p less than 0.05) from 115 +/- 2 on day 0 to 104 +/- 4 on day 9. These results suggest that protein content which is increased during pseudopregnancy could be responsible for the decline of AC activity. However, results obtained on day 9 and 15 suggest that other factors are involved. Dose responses to ISO during PG showed an alteration in response on days 6.5 and 9 at ES. It was reflected by a higher stimulation at suboptimal (0.1 microM) and optimal doses (100 microM). These results suggest that myometrial AC activity could be regulated by the presence of the embryo.
Asunto(s)
Adenilil Ciclasas/metabolismo , Embrión de Mamíferos/fisiología , Miometrio/enzimología , Embarazo/metabolismo , Seudoembarazo/metabolismo , Animales , Dinoprostona/farmacología , Femenino , Guanosina Trifosfato/farmacología , Isoproterenol/farmacología , Cinética , Conejos , Valores de Referencia , Fluoruro de Sodio/farmacologíaRESUMEN
Cyclic adenosine 3'-5'-monophosphate (cAMP) is the likely mediator of myometrial relaxation induced by agents like isoproterenol and relaxin. In vivo, the relaxation response to beta-adrenergic catecholamines is modulated by estradiol (E2) and progesterone (P) during the estrous cycle and pregnancy. However, it is still debated whether that regulation occurs via a direct action on myometrial cells or indirectly through modulation of adrenergic neurotransmitters. We have studied the properties of adenylate cyclase in primary cultures of smooth muscle cells isolated from rabbit myometrium. Adenylate cyclase activity increased with time in culture reaching a maximum on day 6. The cultured cells had basal activity which could be stimulated by guanosine triphosphate (GTP, 2.3 fold), its non-hydrolysable analogue guanylyl-imido-diphosphate (GPP[NH]p, 8.3 fold) and sodium fluoride (NaF, 15.7 fold). Isoproterenol (Iso) and prostaglandin E2 (PGE2) stimulated adenylate cyclase activity to the same level (4 fold) and required the presence of exogenous GTP. Sex steroid treatment did not affect basal activity or its stimulation by guanyl nucleotides, PGE2 or NaF. However, the adenylate cyclase response to Iso was significantly affected by E2 and/or P treatment. E2 treatment for 6 days diminished the sensitivity 10 fold (from 10 nM to 100 nM) while E2 for 3 days followed by P for 3 days increased it 10 fold (to 1 nM). Maximal response was not affected by treatment with E2 for 6 days but was diminished by 43% (p less than 0.001) when P was added alone and increased by 63% (p less than 0.001) when P was added following E2 pretreatment. Our results demonstrate that sex steroids can alter beta-adrenergic response in vitro by a direct action on myometrial cells.
Asunto(s)
Adenilil Ciclasas/análisis , Hormonas Esteroides Gonadales/farmacología , Miometrio/efectos de los fármacos , Receptores Adrenérgicos beta/efectos de los fármacos , Animales , Células Cultivadas , Femenino , Guanosina Trifosfato/farmacología , Isoproterenol/farmacología , Miometrio/enzimología , Conejos , Contracción Uterina/efectos de los fármacosRESUMEN
Epithelial and stromal cells were isolated from endometrium of Day 1 pseudopregnant rabbits by enzymatic digestion with trypsin or trypsin:collagenase:deoxyribonuclease. Dispersed cells were grown in RPMI 1640 supplemented with 10% whole or steroid-depleted fetal bovine serum (FBS). Epithelial and stromal cells reached confluency after 6 to 7 days in culture and showed specific characteristics. Cells could be differentiated according to morphology, growth patterns, electrophoretic patterns, and response to estrogen or progesterone. Hormonal stimulation of adenylate cyclase activity was measured in broken cell preparations by catalytic transformation of alpha-32P-adenosine triphosphate into 32P-adenosine 3'-5' cyclic monophosphate (cAMP). Adenylate cyclase activity was present in fresh endometrial tissue and in dispersed cells after 7 days in culture. The enzyme activity was significantly higher in stromal than in epithelial cells at all stimulation levels: basal (9.2 +/- 1.0 vs. 2.3 +/- 0.6, p less than 0.001) and guanosine triphosphate (GTP, 300 microM) (25.4 +/- 2.9 vs. 7.0 +/- 1.6, p less than 0.001). Net response to prostaglandin E2 (PGE2, 10 microM) was three times higher (p less than 0.001) in stromal (17 +/- 2) than in epithelial (5.0 +/- 1) cells. These results suggest that PGE2 can stimulate adenylate cyclase in rabbit endometrium and that the enzyme is preferentially localized in the stroma. Our results are in agreement with the hypothesis that cAMP formed in endometrium in response to PGE2 might be involved in the decidual reaction.
Asunto(s)
Adenilil Ciclasas/metabolismo , Endometrio/enzimología , Prostaglandinas E/farmacología , Animales , Células Cultivadas , Dinoprostona , Endometrio/citología , Endometrio/efectos de los fármacos , Epitelio/enzimología , Estradiol/farmacología , Femenino , Cinética , Progesterona/farmacología , Seudoembarazo , ConejosRESUMEN
Myometrial cells were obtained following a three-step enzymatic digestion of uterine horns from Day 1 pseudopregnant rabbits. Isolated cells were cultured in RPMI 1640 supplemented with 10% fetal bovine serum (FBS), whole or steroid depleted (FBS-DC) at a plating density of 0.5 X 10(6) cells/ml. The cells reached confluency on Day 6 to 7 with whole serum and on Day 7 to 8 with DC serum. The process yielded myometrial cells at a purity level of at least 80% as assessed by indirect immunofluorescence using desmin antibody on confluent cultures. The addition of increasing doses of 17 beta-estradiol (E2) (0.1 nM to 1 microM) to the culture medium resulted in an increase in total protein and DNA content (1.5-fold at 1 nM). Similar treatment with progesterone (P) resulted in a 25% inhibition of protein and DNA content at 10 nM. Pretreatment of cells with E2 (1 nM) for 3 d followed by P (10 nM) for 3 d resulted in a 1.8-fold stimulation of protein with a higher protein: DNA ratio indicating that the increase was due to cellular hypertrophy. Analysis of desmin by polyacrylamide gel electrophoresis showed that this cytoskeleton protein was not affected by steroid treatment. Our results indicate that PR can generate two different responses depending on cell pretreatment. In as much as myometrial cells grown in primary culture respond differentially to E2 and P they should provide a useful model to study the regulation of myometrial contractility.