SK11472002A3 - Compounds useful for the treatment or prevention of a disease mediated by the alpha-2b-adrenoceptor - Google Patents

Abstract

The present invention relates to the use of a selective alpha-2B-adrenoceptor antagonist for the manufacture of a pharmaceutical preparation useful for the treatment or prevention of a disease mediated by the alpha-2B-adrenoceptor in a mammal. Said antagonist is a compound selected from the group consisting of compounds A, B, C, D and E disclosed in Scheme I, or a pharmaceutically acceptable salt of said compound. The present invention also relates to a method for the treatment or prevention of a disease mediated by the alpha-2B-adrenoceptor in a mammal. Said method comprises administering to said mammal an effective amount of said selective alpha-2B-adrenoceptor antagonist.

Description

Technical field

The invention relates to the use of selective alpha-2B-adrenoceptor antagonists for the manufacture of pharmaceutical compositions suitable for the treatment or prevention of alpha-2B-adrenoceptor mediated diseases in mammals. The present invention also relates to a method of treating or preventing a disease mediated by alpha-2B-adrenoceptors in a mammal and to a method of administering said selective alpha-2B-adrenoceptor antagonists to said mammal.

BACKGROUND OF THE INVENTION

The publications and other materials used herein to illustrate the art of the invention, and in particular cases providing further details with respect to practice, are incorporated herein by reference.

The selective alpha-2B-adrenoceptors shown in FIG. 1, see below, are previously well known. Starting from compound A (order number AE-848/34956037), C (order number AF-399/36012031) and D (order number AH-034/34347043) from ŠPECS and BioŠPECS BV, Fleminglaan 16, 2289 CP Rijswijk, The Netherlands . Compound B (Order No. 653716) and E (Order No. 569063) were purchased from ChemBridge Corporation, 16981 Via Tazon, Suite G, San Diego CA 92127.

It is known that vascular contraction is mediated by alpha-2B-adrenoceptors. Therefore, alpha2B-antagonists are useful in the treatment or prevention of diseases in which quascular contraction occurs. It has also been found that gene polymorphism is found in the alpha-2Badrenoceptor gene in some people. It has been observed that in some individuals the alpha2B-adrenoceptoma protein has 3 glutamate deletions in the glutamic acid repeat region where 12 glutamates are repeated (amino acids 297-309), in the 17 amino acid acid region located in the third intracialule loop of the receptor polypeptide ( Heinonen et al., 1999).

SUMMARY OF THE INVENTION

It has now been found that compounds selected from the group consisting of compounds A, B, C, D and E, the formulas of which are shown in FIG. 1, are selective alpha-2Badrenoceptor antagonists.

Accordingly, the present invention is directed to the use of selective alpha-2B-adrenoceptor antagonists for the manufacture of pharmaceutical compositions for the treatment or prevention of alpha-2B-adrenoceptor mediated diseases in mammals. According to the invention, wherein said antagonist is a compound selected from the group consisting of compounds: A, B, C, D and E shown in FIG. 1, or a pharmaceutically acceptable salt thereof.

The invention also provides a method of treating or preventing a disease mediated by alpha-2B-adrenoceptor in a mammal, said method comprising administering to said mammal an effective amount of a selective alpha-2B-adrenoceptor antagonist, said antagonist being a compound selected from the group consisting of: A, B , C, D and E shown in FIG. 1, or a pharmaceutically acceptable salt thereof.

Alpha-2B-adrenoceptor antagonists are useful in the treatment and / or prevention of many diseases.

Persons with a deletion in the alpha-2B-adrenoceptoma protein (Heinonen et al., 1999), particularly the deletion / deletion genotype (D / D genotype), are an important target group for whom the administration of selective alpha-2B- antagonists is adrenoceptora beneficial.

During a five-year study, the risk of acute myocardial infarction (AMI) was found to be significantly higher in the group of Finnish middle-aged men with a D / D genotype for the alpha-2B-adrenoceptor gene. The risk of AMI was even higher in subjects who were not diagnosed with coronary heart disease (CHD) at the start of the study. Thus, it is suggested that the D / D genotype is associated with a lack of ability to regulate alpha2B-adrenoceptor function during continuous receptor activation. Therefore, alpha-2Badrenoceptors are likely to play a role in the pathogenesis of a significant number of all AMI cases, especially in individuals with the D / D genotype but also in individuals with the I / D and I / I genotype (I means insertion and denotes normal allele) .

Alpha-2B-adrenoceptor antagonists, as encompassed by the invention, could be of great use in the treatment or prevention of coronary heart disease. Examples include:

(a) Acute AMI

If alpha-2B-adrenoceptor-dependent vasoconstriction is the cause of some cases of AMI, then antagonism of these receptors should restore coronary circulation and reduce the damage caused by constriction of the coronary arteries.

b) Unstable angina pectoris

The alpha-2B-adrenoceptor antagonist releases the vasoconstrictor component during the ischemic event, thus alleviating the symptoms and helping to prevent AMI.

c) Prinzmetal variant angina pectoris

Vasoconstriction is a key factor in the pathogenesis of Prinzmetal angina, and an alpha-2B-adrenoceptor antagonist can help prevent seizures.

d) Other forms of chronic angina pectoris and CHD

The alpha-2B-adrenoceptor antagonist will help relieve the vasoconstrictor component in all types of CHD, providing both symptomatic relief and protection from AMI. An overall reduction in vascular tension will contribute to this by reducing venous resistance, cardiac load and oxygen consumption (nitrate type effect, see below).

(e) Prevention of restenosis after coronary plasticization of blood vessels (angioplasty) in cases where vasoconstriction may play a role in the development of restenosis.

Furthermore, alpha-2B-adrenoceptor antagonists as encompassed by the present invention could be useful in the treatment or prevention of underlying hypertension, particularly in persons with increased sympathetic nervous system activity and hyperdynamic circulatory system.

In the study discussed above, the D / D variant of the alpha-2B-adrenoceptor gene was not clearly associated with blood pressure. This is believed to be due to two major factors, 1) antihypertensive treatment and 2) comprehensive regulation of total blood pressure. In another study (Heinonen et al.), It was observed that the D / D genotype was associated with decreased basal activity and decreased heart rate. This is likely to reflect an increase in vascular resistance in these individuals.

In transgenic mice targeted by the alpha-2B-adrenoceptor gene inactivation, alpha-2-adrenoceptor antagonists administered intravenously failed to elicit the characteristic increase in blood pressure observed in normal animals and also in humans after large doses of such agents (Link et al. , 1996). Obviously, emphasis was placed on the hypotensive effect of these substances. This indicates that alpha-2B-adrenoceptors mediate vascular contraction. This means that the antagonist should lower blood pressure. This effect was not observed with alpha-2B non-selective alpha-2B-adrenoceptor antagonists, as alpha-2Badrenoceptor antagonism increases sympathetic outflow, cardiac output and blood pressure. In mice with alpha-2Badrenoceptor dysfunctional alpha-2-adrenoceptor antagonists caused a pressure increase of α. not hypotension (MacMillan et al., 1996)

The alpha-2B-adrenoceptor antagonist has been shown to have a beneficial effect in hypertensive individuals through its effect on kidney function, blood flow, muscles, as well as vascular resistance in other vascular beds. The anti-AMI effect of these agents will be an additional benefit since hypertension is a significant risk factor for AMI. This protection is due to three factors: 1) reduction of total blood pressure, 2) reduction of the risk of coronary vasoconstriction, and 3) effect of nitrate type on vascular resistance, cardiac load and oxygen consumption.

In addition, alpha-2B-adrenoceptor antagonists, as encompassed by the invention, will be useful in the treatment and prevention of other vascular diseases. The benefits can be especially expected in the treatment or prevention of vascular constriction and brain damage by hypoxia following subarachnoid haemorrhage (pituitary membrane),

- migraines

- Raynauds disease and cold intolerance

- Pre-eclampsia

Erectile dysfunction in men and men

Obesity and so-called. metabolic syndrome.

The latter effect was observed due to the fact that decreased blood flow, muscles and reduced basal metabolic intensity contribute to the development of obesity and high blood pressure. The alpha-2B-adrenoceptor antagonist will increase energy expenditure by increasing blood flow, muscles and shifting calorie balance in the desired direction.

The alpha-2B-adrenoceptor antagonists of the invention are also useful in anesthesia and analgesia to enhance the efficacy of alpha-2B-adrenoceptor antagonists that are not selective for the alpha-2B-adrenoceptor subtype. By blocking the vasoconstriction induced by these antagonists, the coadministered alpha-2B-adrenoceptor antagonist allows the use of higher doses of said antagonists, up to the anesthetic level, which would not be possible in humans, only in veterinary anesthetic practice.

DETAILED DESCRIPTION OF THE INVENTION

Human alpha-2B-adrenoceptor binding affinity

The affinity of the test compounds for the three human α2-adrenoceptor subtypes (α2α, Β2Β and α2c) was determined in a competitive ³ H-rauwolscin binding assay. Biological material for these experiments consisted of membranes from Shionogi SI 15 cells stably inoculated with one of three human α 2 subtypes (Marjamäki et al., 1992) Membrane (5-10 µg total)

5-protein per sample) and 1 nM-2 nM ³ H-rauwolscin (specific activity 78 Ci / mmol) were incubated in 50 mM KH 2 PO 4, pH 7.5 with six different concentrations of compounds. The determination for each concentration was performed twice. Non-specific binding was determined using 100 μΜ of oxymetazoline and corresponded to 5-15% of total binding. After 30 minutes at room temperature, incubation was terminated by rapid vacuum filtration through a GF / B glass fiber filter and the samples were rinsed three times with 5 ml ice incubation buffer. The filters were then dried and impregnated with scintillate and their radioactivity was measured by scintillation counting. Analysis of these experiments was performed using a non-linear least-squares method. Experimentally determined IC 50 values were converted to Ki values using the Cheng-Prusoff equation (Cheng and Prusoff, 1973). The experiments were repeated at least three times.

Table 1: Binding affinities at α 2 -adrenoceptor subtypes

Data are presented as Ki values in nM (± SEM value), n = 3 unless otherwise specified.

compound Alpha-2A Alpha-2B Alpha-2C A 4100 ± 200 30 ± 4 > 4700 C > 30000 (n = 3) 1860 (n = 3) > 30000 (n = 3) D > 30000 530 ± 90 > 30000 B > 30000 215 ± 60 > 30000 E > 100000 2900 ± 300 > 100000

Rat cortical α 1 -adrenoceptor binding affinity

The affinity for rat neocortical α-adrenoceptors (from the neocortex) was determined in competitive ³ H-prazosin binding assays. The biological material for these assays consisted of membranes obtained from rat neocortex (part of the cerebral cortex). A suspension of membranes (100-200 µg total protein per sample) and 0.2 nM - 0.25 nM ³ Hprazosine (specific activity 74 Ci / mmol) was incubated with six different concentrations of compounds in a total volume of 0.25 ml (50 mM Tris). pH 7.7 at 25 ° C). Each concentration was used twice. Non-specific binding was determined using 10 μΜ phentolamine methanesulfonate and corresponded to 25-30% of total binding. After 30 min

The -6 incubation was stopped by rapid filtration through GF / B glass fiber filter mats and the filtrate was washed three times with ice-cold Tris 10 mM (pH 7.7 at 4 ° C). After drying, the solid scintillate was dissolved on filter mats and radioactivity was determined by scintillation counting.

The results

At concentrations up to 30 μΜ, Compound A caused only an insufficient displacement of ³ H-prazosin to estimate the IC 50 value. Therefore, the IC 50 and K i for Compound A are reported to be> 30,000 nM.

Antagonist activity of human d2-adrenoceptor subtypes

The antagonistic effect was determined as the ability of the test compounds to competitively inhibit epinephrine-stimulated ³⁵ S-GTPγS binding to G proteins (Tian et al., 1993; Wieland and Akobs, 1994; Jasper et al., 1998) in CHO cell membranes stably inoculated with one of three. human (X2 subtypes (Pohjanoksa et al., 1997; Maijamäki et al., 1998). Membranes (2 to 6 µg total protein per sample) and 12 different concentrations of test compounds were preincubated for 30 minutes at room temperature with the same epinephrine concentration (5 μΜ for (12a, 15 μΜ for a2B, 5 μΜ for 012c) in 50 mM Tris, 5 mM MgCl 2, 150 mM NaCl, 1 mM DTT, 1 mM EDTA, 10 μΜ GDP, 30 μΜ ascorbic acid, pH 7.4. radiolabeling was started by adding trace amounts of ³⁵ S-GTPγS (0.08 nM - 0.15 nM, specific activity 1250 Ci / mmol) to the incubated mixture, and after an additional 60 minutes at room temperature, the incubation was terminated by rapid vacuum filtration through a sk. The filters were washed three times with 5 ml ice wash buffer (20 mM Tris, 5 mM MgCl ₂ , 1 mM EDTA, pH 7.4 at room temperature), dried and radioactivity counted on a scintillation detector. Evaluation of the experiments was performed using a non-linear least-squares method. The experiments were repeated at least three times.

Table 2: Antagonistic effect of compound A and compound B on the human α 2 -adrenoceptoma subtype

Data are reported as KB in nM (± SEM value), n are at least three experiments.

compound Alpha-2A * Alpha-2B Alpha-2C * A 2400 ± 700 73 ± 23 2400 ± 900 B > 10000 250 ± 80 > 10000

-Ί * only incomplete dose response curves could be obtained, KB values are minimal estimates

For the purpose of the invention, an alpha-2B-adrenoceptor antagonist as shown in FIG. I, or a pharmaceutically acceptable salt thereof, may be administered by various routes. Suitable forms for administration include, for example, oral preparations: parenteral injections including intravenous, intramuscular, intradermal and subcutaneous injections; administration forms to the skin or rectal administration forms. The required dosage of the alpha-2Badrenoceptor antagonist compounds will vary depending upon the particular condition being treated, the severity, the duration of treatment, the route of administration chosen and the compound employed. A suitable dose is in the range of 5 µg to 100 mg per kg body weight per day in adults.

It would be appreciated that the methods of the invention be included in the form of various embodiments, only a few of which are disclosed herein. It will be apparent to those skilled in the art that other embodiments also exist and do not depart from the spirit of the invention. Thus, the described embodiments are illustrative only and should not be construed as limiting.

-3Odkazy:

Cheng, Y., and Prusoff, W.H., 1973. Biochem. Pharmacol. 22: 3099

Jasper, J.R., Lesnick, J.D., Chang, L.K., Yamanashi, S.S., Chang, T.C., Hsu, S.A.O., Daunt,

D.A., Bonhaus, D.W., and Egen, R.M., 1998. Biochem. Pharmacol. 55: 1035

Marjamäki, A., Ala-Uotila, S., Luomala, K., Perälä, M., Jansson, C., Jalkanen, M., Regan,

J.W., and Scheinin, M., 1992. Biochem. Biophys. Acta 1134: 169

Marjamäki, A., Pihlavisto, M., Cockroft, V., Heinonen, P., Savola, J. M., and Scheinin, M., 1998. Mol. Pharmacol. 53: 370

Pohjanoksa, K., Jansson, C.C., Luomala, K., Marjamaki, A., Savola, J. -M., And Schenin, M., 1997] Eur. J. Pharmacol. 35: 53

Tian, W. N., Duzic, E., Lanier, S.M., and Deth, R.C., 1993. Mol. Pharmacol. 45: 524

Wieland, T., and Akobs, K.H., 1994. Meth. Enzymol. 237: 3

Heinonen et al. 1999, Journal of Clinical Endocrinology & Metabolism, 84: 2429

Link R E et al., 1996, Science 273: 803

MacMillan L. B et al., 1996, Science 273: 801

Claims (15)

PATENT CLAIMS A compound selected from the group consisting of A, B, C, D and E shown in FIG. I, or a pharmaceutically acceptable salt thereof, for use as a medicament. Use of a selective alpha-2B-adrenoceptor antagonist for the manufacture of a medicament for the treatment or prevention of alpha-2B-adrenoceptor-mediated diseases in mammals, wherein the antagonist is a compound selected from the group consisting of: A, B, C, D and E Fig. I, or a pharmaceutically acceptable salt thereof. The use of claim 2, wherein the disease is coronary heart disease (CHD). The use of claim 3, wherein the disease is - acute myocardial infarction (AMI) - unstable angina pectoris Prinzmetal's variant form of angina pectoris other forms of chronic angina pectoris and coronary heart disease, or - restenosis after coronary angioplasty. The use of claim 2, wherein the disease is essential hypertension. The use of claim 2, wherein the disease is a vascular disease that is - vasoconstriction or brain damage by hypoxia after subarachnoid haemorrhage, - migraine -Raynauds disease and cold intolerance - pre-eclampsia erectile dysfunction in men and men -obezita. Use of a selective alpha-2B-adrenoceptor antagonist for the manufacture of a pharmaceutical composition for enhancing the clinical efficacy of the anesthetic and / or analgesic alpha-2-adrenoceptor antagonist, wherein the agonist is not selective for the alpha-2B-adrenoceptor subtype. -1C- A method of preventing an alpha-2B-adrenoceptor-mediated disease in a mammal comprising administering to said mammal an effective amount of a selective alpha-2B-adrenoceptor antagonist, wherein the antagonist is a compound selected from the group consisting of A, B, C, D and E shown in FIG. . I, or a pharmaceutically acceptable salt thereof. The method of claim 8, wherein the disease is coronary heart disease (CHD). The method of claim 8, wherein the disease is -acute myocardial infarction (AMI) -stable angina pectoris -Princmetal variant form of angina pectoris - other forms of chronic angina and CHD; or - restenosis after coronary angioplasty. The method of claim 8, wherein the disease is essential hypertension. The method of claim 8, wherein the disease is a vascular disease that is - vasoconstriction or brain damage by hypoxia after subarachnoid haemorrhage - migraine -Raynauds disease and cold intolerance -for-eclampsia - erectile dysfunction in men or obesity. The method of claim 8, wherein the alpha-2B-adrenoceptor antagonist is administered to a mammal to enhance the clinical efficacy of the anesthetic and / or analgesic alpha-2adrenoceptor antagonist, wherein the agonist is not selective for the alpha-2B-adrenoceptor subtype. The method of claim 8, wherein the alpha-2B-adrenoceptor antagonist is administered to persons having a 3 glutamate deletion in the glutamic acid repeat region where 12 glutamates are repeated (amino acids 297-309), in the 17 amino acid acid region located in a third intracialular loop of the receptor polypeptide. The method of claim 13, wherein the person is a carrier of the deletion / deletion genotype.