RU2306930C1 - Method for correction of endothelial dysfunction with combination of losartan and l-arginine in l-name-induced nitrogen deficit - Google Patents

Abstract

FIELD: medicine, pharmacology.

SUBSTANCE: endothelial dysfunction is modulated in Wistar-line rats by daily intraperitoneal administering of L-nitro-arginine-methyl ester in dose of 25 mg/kg for 7 days and losartan is administered intragastrically in dose of 200 mg/kg one time per day.

EFFECT: method for correction of endothelial dysfunction due to synergistic action of losartan and L-arginine.

2 tbl, 1 ex

Description

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

Closest to the claimed solution is a method for the correction of endothelial dysfunction using losartan, which is an antagonist of angiotensin II receptors (AT 1 subtype), described by 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, p.11-16, which consists in the oral administration of drugs of this group in patients for the correction of endothelial dysfunction.

The main disadvantage of this method is the indirect mechanism of action of losartan in endothelial dysfunction, associated with stimulation of the AT 2 subtype of angiotensin II receptors and realized as a result of the bradykinin-dependent pathway of endothelioprotection, while damage to to the L-arginine NO system, which leads to a disruption in the production of nitric oxide (NO), the activity of which when using only losartan remains not sufficiently compensated. Therefore, the results of the correction of endothelial dysfunction due to damage in the L-arginine NO system, which is mainly associated with deficiency of endothelial NO synthase, with the help of losartan are unsatisfactory.

The technical result of the invention is a method for the correction of endothelial dysfunction, including the use of losartan, which is an antagonist of angiotensin II receptors (AT 1 subtype) and an NO-L arginine donor.

The technical result is achieved by the fact that, against the background of modeling endothelial dysfunction in the experiment, an intraperitoneal administration to the laboratory animal for 7 days of the synthesis blocker of NO L-nitro-arginine-methyl ether (L-NAME) at a dose of 25 mg / kg is corrected by intragastric administration of losartan at a dose of 6 mg / kg once a day and intraperitoneal administration of a donor of NO L-arginine at a dose of 200 mg / kg also once a day, which leads to activation of the correction of endothelial dysfunction, since L-arginine is the main subs Rath for NO synthesis and, simultaneously, its enzymatic pathway activator formation in the vascular endothelium.

The method is carried out 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.

EXAMPLE OF 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 losartan (6 mg / kg intragastrically) did not lead to a decrease in the initial BP values (SBP - 192.2 ± 10.5, DBP - 138.2 ± 2.4 mm Hg), and in experiments where L-arginine was additionally introduced (200 mg / kg intraperitoneally), potentiation of the hypotensive effect was noted, since the initial numbers of blood pressure were significantly lower: SBP - 165.0 ± 6.2, DBP - 131.1 ± 4.3 mmHg. (table 1).

Table 1
Dynamics of blood pressure and heart rate in modeling nitric oxide deficiency and correction of endothelial dysfunction with losartan using L-arginine Groups of animals Functional Tests GARDEN, mmHg DBP, mmHg Heart rate, beats in min 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) + Losartan (6 mg / kg) Source 192.2 ± 10.5 * 138.2 ± 2.4 * 415.0 ± 9.0 EZV with AH 90.0 ± 7.8 * 51.7 ± 5.0 * 425.0 ± 11.0 ENZV with NP 95.5 ± 8.9 55.5 ± 5.5 430.0 ± 11.0 L-NAME (25 mg / kg) + Losartan (6 mg / kg) + L-arginine (200 mg / kg) Source 165.0 ± 6.2 ** 131.1 ± 4.3 ** 372.0 ± 17.0 EZV with AH 94.0 ± 5.5 ** 87.0 ± 2.8 ** 357.0 ± 16.0 ENZV with NP 105.1 ± 5.3 85.1 ± 5.9 376.0 ± 14.0 * - p <0.05 compared with the group of intact
** - p <0.05 compared with the L-NAME + losartan 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 only losartan was administered against the background of the administration of the NO synthase inhibitor L-NAME, this ratio corresponded to a value of 2.3 ± 0.3, and in the group with the additional introduction of the donor NO L-arginine to losartan, 1.7 ± 0.1 (table 2).

table 2
Indicators reflecting the correction of endothelial dysfunction with the introduction of L-NAME losartan and losartan 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 + Losartan OH 91.7 ± 4.7 29.7 ± 1.9 1048.9 ± 79.8 2.3 ± 0.3 NP 93.0 ± 7.0 74.8 ± 8.6 3523.4 ± 535.9 L-NAME + Losartan L-Arginine OH 89.3 ± 3.3 37.8 ± 4.3 1653.7 ± 143.2 1.7 ± 0.1 * NP 92.0 ± 5.0 75.5 ± 6.2 3458.3 ± 347.8 * - p <0.05 compared with the group L-NAME + losartan

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

Claims (1)

A method for correcting endothelial dysfunction, including the administration of losartan, characterized in that the Wistar rats in the experiment simulate dysfunction by daily intraperitoneal administration of L-nitro-arginine methyl ester to rats at a dose of 25 mg / kg and losartan is intragastrically administered against this background a dose of 6 mg / kg and L-arginine intraperitoneally at a dose of 200 mg / kg once a day.