Glycine blocks the pressor response to L-glutamate microinjected into the nucleus tractus solitarii of conscious rats. 1995

H Mauad, and E Colombari, and L G Bonagamba, and B H Machado
Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.

Microinjection of L-glutamate into the nucleus tractus solitarii (NTS) of conscious freely moving Wistar rats (240-260 g) produces pressor (+48 +/- 4 mmHg) and bradycardic (-153 +/- 20 bpm) responses. In the present study L-glutamate (2.5 nmol/100 nl) was microinjected before and after microinjection of increasing doses of glycine (10, 25 and 50 nmol/100 nl, N = 6) or saline (vehicle/100 nl, N = 6) into the NTS. Microinjections of increasing doses of glycine into the NTS produced a dose-dependent reduction in the pressor but not in the bradycardic responses to L-glutamate. [10 nmol (+29 +/- 5 mmHg and -110 +/- 18 bpm), 25 nmol (+12 +/- 7 mmHg and -88 +/- 21 bpm) and 50 nmol (+4 +/- 2 mmHg and -100 +/- 31 bpm)] The dose-dependent blockade of the pressor response to L-glutamate by glycine suggests an inhibitory neuromodulatory role for this amino acid in the sympatho-excitatory activity produced by L-glutamate microinjection into the NTS.

UI MeSH Term Description Entries
D008297 Male Males
D008845 Microinjections The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes. Microinjection
D001794 Blood Pressure PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS. Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D003243 Consciousness Sense of awareness of self and of the environment. Consciousnesses
D005998 Glycine A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter. Aminoacetic Acid,Glycine, Monopotassium Salt,Glycine Carbonate (1:1), Monosodium Salt,Glycine Carbonate (2:1), Monolithium Salt,Glycine Carbonate (2:1), Monopotassium Salt,Glycine Carbonate (2:1), Monosodium Salt,Glycine Hydrochloride,Glycine Hydrochloride (2:1),Glycine Phosphate,Glycine Phosphate (1:1),Glycine Sulfate (3:1),Glycine, Calcium Salt,Glycine, Calcium Salt (2:1),Glycine, Cobalt Salt,Glycine, Copper Salt,Glycine, Monoammonium Salt,Glycine, Monosodium Salt,Glycine, Sodium Hydrogen Carbonate,Acid, Aminoacetic,Calcium Salt Glycine,Cobalt Salt Glycine,Copper Salt Glycine,Hydrochloride, Glycine,Monoammonium Salt Glycine,Monopotassium Salt Glycine,Monosodium Salt Glycine,Phosphate, Glycine,Salt Glycine, Monoammonium,Salt Glycine, Monopotassium,Salt Glycine, Monosodium
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D017208 Rats, Wistar A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain. Wistar Rat,Rat, Wistar,Wistar Rats
D017552 Solitary Nucleus GRAY MATTER located in the dorsomedial part of the MEDULLA OBLONGATA associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of AUTONOMIC NERVOUS SYSTEM regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of HOMEOSTASIS. The solitary nucleus is also notable for the large number of NEUROTRANSMITTERS which are found therein. Nucleus Solitarius,Nuclei Tractus Solitarii,Nucleus Tractus Solitarii,Nucleus of Solitary Tract,Nucleus of Tractus Solitarius,Nucleus of the Solitary Tract,Solitary Nuclear Complex,Solitary Tract Nucleus,Complex, Solitary Nuclear,Complices, Solitary Nuclear,Nuclear Complex, Solitary,Nuclear Complices, Solitary,Nuclei Tractus Solitarius,Nucleus Tractus Solitarius,Nucleus, Solitary,Nucleus, Solitary Tract,Solitarii, Nuclei Tractus,Solitarius Nucleus, Tractus,Solitarius, Nuclei Tractus,Solitary Nuclear Complices,Tractus Solitarii, Nuclei,Tractus Solitarius Nucleus,Tractus Solitarius, Nuclei
D017704 Baroreflex A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure. Reflex, Baroreceptor,Baroreceptor Reflex,Baroreceptor Reflexes,Baroreflexes,Reflexes, Baroreceptor
D051381 Rats The common name for the genus Rattus. Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus

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