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Biomedical subjects

A Velasco

Publications and source records attributed to A Velasco.

At least 127 records · Page 7Linked to original sources
PubMed1982

Carbohydrate cytochemistry on hypodermic lymphatic endothelium of the green lizard, Lacerta hispanica.

A cytochemical study on the endothelium of the hypodermic lymphatic capillaries of the green lizard, Lacerta hispanica, has been carried out. The dialysed iron method produced a homogeneous precipitate on the surface of the endothelial cells and on the inside of the endocytic vesicles. The periodic acid-thiocarbohydrazide-silver proteinate, low pH phosphotungstic acid and high iron diamine techniques gave negative results. The carbohydrates in the capillaries thus seem to be glycosaminoglycans with carboxyl groups. The possible role of these glycosaminoglycans in the formation of the endocytic vesicles is discussed.

Animals↗
PubMed1980

Effect of amphetamine and dopamine on oxygen uptake of rat brain slices in vitro.

Effects of d-amphetamine and dopamine on rat brain cortical slices respiration were estimated to assess whether these drugs might modify membrane (Na+ + K+)-ATPase activity in intact cells as they do in isolate enzyme systems. d-Amphetamine, 10(-5) M (140%), 10(-6) M (123%) 10(-7) M (131%) and 10(-7) M (129%). These results may be related to estimates of (Na+ + K+)-ATPase activity in subcellular systems. In an incubation medium containing calcium, 10(-4) M ouabain does not modify brain slices respiration, but fully antagonizes oxygen consumption increases induced by d-amphetamine or dopamine, which might thus be mediated by membrane ATPase activity. Either phenoxybenzamine, oxprenolol or halo-peridol, nullify those metabolic effects of d-amphetamine and dopamine, by means of unspecific mechanisms rather than by a specific interaction at drug receptor sites. It is suggested that cell respiratory control is the final resultant of mechanisms which might be separately, and oppositely, modified by drugs.

Amphetamine↗
PubMed1973

Interaction between tyramine and iproniazid on guinea-pig atria.

The inhibition of monoamine oxidase (MAO) by iproniazid may be antagonized by large doses of tyramine as shown by the restoration, or otherwise, of inotropic responses to tyramine in isolated atria from guinea-pigs that had been treated with reserpine.

Animals↗