RU2364393C1 - Method of picamilonum-based correction of endothelial dysfunction in l-name induced nitric oxide deficiency - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to experimental cardiology and pharmacology. It implies simulation of endothelial dysfunction in Wistar albino male rats in experiment through daily intraperitoneal introduction of N-nitro-L-arginine methyl ester in a dose 25 mg/kg within 7 days. It is followed with daily intragastric introduction of Picamilonum 30 mg/kg within next 7 days.

EFFECT: method provides effective correction of endothelial dysfunction in specific simulation environment.

1 ex, 2 tbl

Description

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

Closest to the claimed solution is a method of pharmacological correction of endothelial dysfunction with GABAergic derivatives, described by I.N. Tyurenkov, A.V. Voronkov, A.I. Robertus in the article "Pharmacological correction of endothelial dysfunction caused by hormonal deficiency", Psychopharmacology and biological narcology, 2007, v. 7, special. issue, part 2, p. 1983, which consists in the introduction of GABAergic agents - RGPU-189 (15 mg / kg), RGPU-147 and RGPU-38 (50 mg / kg) in modeling experimental diabetes mellitus and in case of sexual insufficiency hormones. Endothelial function was tested by the introduction of acetylcholine with registration of blood flow in the cerebral cortex.

The main disadvantage of this method is the correction of endothelial dysfunction by GABAergic derivatives under conditions of decreasing bioavailability of nitric oxide and hormonal deficiency caused by the administration of streptozocin and castration of animals, as well as the lack of assessment of the functional state of the vascular bed in a holistic organism when modeling nitric oxide deficiency. 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 GABAergic agents are unsatisfactory.

The technical result of the invention is a method for the correction of endothelial dysfunction with L-NAME induced nitric oxide deficiency, including the use of a GABAergic agent picamilon. The technical result is achieved by the fact that, against the background of modeling endothelial dysfunction in the experiment, an intraperitoneal daily administration to the laboratory animal for 7 days of the blocker of the synthesis of NO N-nitro-L-arginine methyl ester (L-NAME) at a dose of 25 mg / kg is carried out by daily

intragastric administration of picamilon at a dose of 30 mg / kg.

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. GABAergic agent - picamilon is administered simultaneously with L-NAME at a dose of 30 mg / kg / day. On the 8th 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 Biopac 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 PERFORMANCE

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 an average arterial pressure (SRAD) of 53.9 ± 2.7 mm Hg, while in 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 picamilon led to a significant decrease in the initial BP values (table 1).

Table 1

Dynamics of blood pressure and heart rate in L-NAME-induced nitric oxide deficiency and correction of endichelial dysfunction with picamilon

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) + picamilon 30 mg / kg Source 153.5 ± 12.4 ** 109.4 ± 14.2 ** 387.3 ± 17.9 ** EZV with AH 105.0 ± 6.3 54.4 ± 3.9 ** 380.1 ± 16.1 ENZV with NP 100.5 ± 3.8 39.4 ± 2.5 389.9 ± 12.9 * - p <0.05 in comparison with the intact group; ** - p <0.05 compared with the L-NAME 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 need to derive a special indicator characterizing the degree of endothelial dysfunction, which is the ratio of the area of the triangle over the trend of the reaction of blood pressure restoration in response to the introduction of NP to the area triangle above the trend of the reaction of restoration of blood pressure 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, to further evaluate the effect of AH and NP in ESV and ENZV, we used this ratio as an indicator of correction of endothelial dysfunction. So, in the group where picamilon was introduced against the background of the administration of the NO synthase inhibitor L-NAME, this ratio corresponded to 1.8 ± 0.3 (table 2).

table 2

Indicators reflecting the correction of endothelial dysfunction on the background of L-NAME-induced nitric oxide deficiency

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 Intact OH 59.9 ± 2.9 42.2 ± 0.8 1268.0 ± 74.8 1.1 ± 0.1 NP 61.0 ± 3.0 45.1 ± 1.0 1375.3 ± 93.7 L-NAME OH 68.0 ± 4.1 20.0 ± 1.4 b95.3 ± 87.6 * 5.4 ± 0.6 * NP 98.0 ± 2.0 67.4 ± 1.4 3322.7 ± 11b, 7 * L-NAME + Picamilon 30 mg / kg OH 65.4 ± 11.3 39.0 ± 2.7 ** 1258.2 ± 247.9 ** 1.8 ± 0.3 ** NP 84.5 ± 14.7 68.7 ± 8.9 2955.2 ± 553.7 * - p <0.05 compared to the intact group, ** - p <0.05 compared to the L-NAME group

Thus, the results obtained allow us to ascertain the correction of endothelial dysfunction with picamilon against the background of L-NAME-induced nitric oxide deficiency.

Claims (1)

A method for the correction of endothelial dysfunction, characterized in that in an experiment with white rats, males of the Wistar strain with endothelial dysfunction against the background of its modeling by intraperitoneal administration of an inhibitor of endothelial synthase N-nitro-L-arginine methyl ester at a dose of 25 mg / kg daily, for 7 days, assessing the degree of development of dysfunction in relation to the indices of endothelium-independent and endothelium-dependent vasodilation, picamilon (30 mg / kg) is intragastrically administered daily for 7 days.