[The possible participation of N-methyl-D-aspartate receptors in the stimulating action on respiration of thyroliberin and its analog RGH 2202].

The effects of ketamine and an antagonist of N-methyl-D-aspartate receptors dibenzocyclohepteniline maleate (MK-801) on the changes in the bioelectrical activity of the diaphragm induced by thyroliberine and its analogue L-pyro-2-aminoadipil-L-leucyl-proline amide (RGH 2202) were studied in experiments on vagotomized urethane-anesthetized rats. It was shown that ketamine (5 mg/kg, intravenously) and MK-801 (1 mg/kg, intravenously) eliminate and prevent an increase of the index of pulmonary ventilation caused by thyroliberine (5 mg/kg, intravenously) and RGH 2202 (5 mg/kg, intravenously). The data obtained suggest the involvement of N-methyl-D-aspartate receptors in the mechanism of the stimulating effects of thyroliberine and its analogue on respiration.