RU2296566C1 - Method for correction of endothelial dysfunction by combination of amlodipine and l-arginine in l-name-induced deficiency of nitrogen oxide - Google Patents

Abstract

FIELD: medicine, experimental cardiopharmacology.

SUBSTANCE: dysfunction is modeled in experiment by every day intraperitoneal administration to rats of L-arginine nitromethyl ester for 7 days in the dose 25 mg/kg. On this background amlodipine is administrated into stomach in the dose 0.5 mg/kg, and L-arginine is administrated by intraperitoneal route in the dose 200 mg/kg once per 24 h. Method provides effective correction under the definite modeling conditions.

EFFECT: improved method of dysfunction correction.

2 tbl, 1 ex

Description

The invention relates to medicine, in particular to experimental cardiopharmacology.

Closest to the claimed solution is a method of correcting endothelial dysfunction using amlodipine, which is a calcium antagonist of the dihydropyridine series. According to the description of V.S. Zodionchenko, T.V. Adasheva, A.P. Sandomirskaya in the article “Endothelial dysfunction and arterial hypertension: therapeutic possibilities”, Russian Medical Journal, Volume 10, 2002, pp. 11-16, which consists in oral administration of drugs of this group in patients for the correction of endothelial dysfunction.

The main disadvantage of this method is the mediated mechanism of action of amlodipine in endothelial dysfunction, associated with its antioxidant properties, increased activity of superoxide dismutase and by reducing the destruction of NO in the vessel wall, as a result, increasing the bioavailability of nitric oxide (NO). However, one of the main factors in the development of this pathophysiological state, especially with essential arterial hypertension, is damage to the L-arginine-NO system, which leads to impaired basal release of nitric oxide (NO), which is not corrected when using only amlodipine, since in the presence of inhibitor of NO synthase, it does not have a sufficient effect. Therefore, the results of the correction of endothelial dysfunction in case of damage in the L-arginine-NO system, which is mainly associated with the deficiency of endothelial NO synthase with amlodipine, are unsatisfactory.

The technical result of the invention is a method for the correction of endothelial dysfunction, including the use of amlodipine, a calcium antagonist of the dihydropyridine series and a donor of NO - L-arginine.

The technical result is achieved by the fact that, against the background of modeling endothelial dysfunction in an experiment, an intraperitoneal injection of a blocker of NO synthesis of L-nitro-arginine-methyl ether (L-NAME) at a dose of 25 mg / kg is carried out by intraperitoneal administration of amlodipine in a laboratory animal for 7 days a dose of 0.5 mg / kg once a day and an intraperitoneal injection of a donor of NO L-arginine at a dose of 200 mg / kg also once a day, which leads to increased correction of endothelial dysfunction, since L-arginine is the main sub a stratum for the synthesis of NO and at the same time an activator of its enzymatic pathway of formation in the vascular endothelium.

The method is as follows

The experiments were carried out on white rats male Wistar line weighing 250-300 g. N-nitro-L-arginine methyl ether (L-NAME) was administered intraperitoneally at a dose of 25 mg / kg / day. On the 7th day from the start of the experiment, a catheter is inserted into the left carotid artery under anesthesia (etaminal sodium 50 mg / kg) to record blood pressure (BP), bolus administration of pharmacological agents is carried out in the right femoral vein. Hemodynamic parameters: systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) are measured continuously using the sensor and the Bioshell computer program. Functional tests: endothelium dependent vasodilation (ESV) - intravenous administration of acetylcholine (AH) at a dose of 40 μg / kg, endothelium independent vasodilation (ENZV) - intravenous administration of sodium nitroprusside (NP) at a dose of 30 μg / kg.

When statistical data processing was calculated, the average value, the standard deviation. Differences were considered significant at p <0.05.

An example of a specific implementation.

A bolus intravenous administration of AH for 3-5 seconds led to a sharp drop in blood pressure, reaching a peak in intact animals for systolic pressure (SBP) 84.3 ± 4.4, for diastolic pressure (DBP) - 38.7 ± 2.8 and for average arterial pressure (SRAD) 53.9 ± 2.7 mm Hg, while during the first 2-3 seconds a sharp bradycardia developed up to 130-150 beats per minute. Recovery of blood pressure occurred on average for 42.2 ± 0.8 seconds after normalization of the heart rhythm. ENZV was also characterized by a decrease in SBP to 83.0 ± 3.7, DBP to 42.1 ± 4.4 and SRAD to 55.7 ± 3.5 mm Hg. followed by complete recovery on average within 45.1 ± 1.0 sec. Blockade of NO synthase by means of prolonged, daily, intraperitoneal administration of L-NAME (N-nitro-L-arginine methyl ester at a dose of 25 mg / kg) for 7 days caused arterial hypertension (SBP - 190.3 ± 6.7 , DBP - 145.0 ± 3.9, SAD - 160.1 ± 4.6 mm Hg) and led to a smaller decrease in blood pressure after administration of AH (SBP to 110.6 ± 5.2, DBP to 82 , 8 ± 6.6, SAD up to 92.1 ± 6.1 mm Hg) and NP (SAD up to 88.7 ± 4.7, DBP up to 50.8 ± 4.2 and SAS up to 63.4 ± 4.1 mmHg) compared with intact animals.

The simultaneous administration of L-NAME and amlodipine (0.5 mg / kg intragastrically) did not lead to a decrease in the initial values of blood pressure (SBP - 186.3 ± 15.2, DBP - 131.1 ± 7.0 mm Hg) , in experiments where L-arginine was additionally introduced (200 mg / kg ip), potentiation of the hypotensive effect was noted: SBP - 144.8 ± 7.6 DBP - 71.6 ± 9.0 mm Hg. (Table 1.).

Table 1 Dynamics of blood pressure and heart rate in modeling nitric oxide deficiency and correction of endothelial dysfunction with amlodipine using L-arginine Groups of animals Functional Tests GARDEN, mmHg DBP, mmHg Heart rate, beats in minutes Intact Source 137.7 ± 3.7 101.9 ± 4.3 420.0 ± 9.0 EZV with AH 84.3 ± 4.5 38.7 ± 2.8 416.0 ± 14.0 ENZV with NP 83.0 ± 3.7 42.1 ± 4.4 415.0 ± 10.0 Receiving L-NAME (25 mg / kg) Source 190.3 ± 6.7 ^* 145.0 ± 3.9 ^* 428.0 ± 11 EZV with AH 110.6 ± 5.2 ^* 82.8 ± 6.6 ^* 426.0 ± 14.0 ENZV with NP 88.7 ± 4.7 50.8 ± 4.2 426.0 ± 13.0 L-NAME (25 mg / kg) + Amlodipine (0.5 mg / kg) Source 186.3 ± 15.2 131.1 ± 7.0 410.0 ± 10.0 EZV with AH 93.1 ± 6.0 ^* 71.6 ± 9.0 ^* 390.0 ± 7.7 ENZV with NP 80.2 ± 7.7 44.1 ± 6.6 420.0 ± 11.0 L-NAME (25 mg / kg) + amlodipine (0.5 mg / kg) + L-arginine (200 mg / kg) Source 144.8 ± 7.6 ^** 111.8 ± 7.6 ^** 390.0 ± 9.7 EZV with AH 77.0 ± 5.3 ^** 47.1 ± 5.7 ^** 379.0 ± 5.7 ENZV with NP 74.4 ± 8.0 42.8 ± 5.1 393.0 ± 6.7 * - p <0.05 in comparison with the group of intact ** - p <0.05 compared with the L-NAME + amlodipine group

The fundamental difference in ESV and ENZV in intact animals and animals with the introduction of an inhibitor of NO synthase L-NAME naturally led us to the necessity of deriving a special indicator characterizing the degree of endothelial dysfunction, which is the ratio of the area of the triangle over the trend in the reaction of restoration of blood pressure in response to the introduction of NP to the area triangle above the trend of the reaction of blood pressure recovery in response to the introduction of AH.

We calculated this ratio for each animal in the intact group and rats after modeling the blockade of NO synthase and obtained a difference of this indicator by a factor of 5 — 1.1 in intact animals and 5.4 in animals treated with L-NAME, respectively.

Thus, for a further assessment of the effect of AH and NP in ESV and ENZV, we used this ratio as an indicator of the correction of endothelial dysfunction. So, in the group where amlodipine was administered only against the background of the administration of the L-NAME synthase inhibitor L-NAME, this ratio corresponded to a value of 2.1 ± 0.3, and in the group with additional administration of the NO donor of L-arginine to amlodipine, 1.5 ± 0.1 (table 2).

table 2 Indicators reflecting the correction of endothelial dysfunction during administration of L-NAME by amlodipine and amlodipine in combination with L-arginine. Groups of animals Functional Tests The increase in the fall of the vascular reaction by SRAD (mm Hg) Vascular reaction time (sec) The area of the vascular reaction (conventional units) The ratio of the areas of the vascular reaction of AH to NP L-NAME + Amlodipine OH 81.7 ± 5.6 39.3 ± 2.3 1350.4 ± 216.9 2.1 ± 0.3 NP 87.0 ± 6.0 68.1 ± 4.6 2771.0 ± 174.3 L-NAME + Amlodipine + L-Arginine OH 82.3 ± 3.5 35.4 ± 1.9 1525.2 ± 218.4 1.5 ± 0.1 * NP 73.0 ± 6.0 59.0 ± 9.5 2274.1 ± 105.1 * - p <0.05 compared with the L-NAME + amlodipine group

Thus, the results obtained indicate the activation of the correction of endothelial dysfunction of amlodipine with a combination of its use with L-arginine.

Claims (1)

A method for correcting endothelial dysfunction, including the administration of amlodipine, characterized in that the experiment simulates dysfunction by daily intraperitoneal administration of L-nitro-arginine methyl ester to rats at a dose of 25 mg / kg and amlodipine is administered intragastrically at a dose of 0, 5 mg / kg and L-arginine intraperitoneally at a dose of 200 mg / kg once a day.