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Biomedical subjects

M M Usardi

Publications and source records attributed to M M Usardi.

At least 19 recordsLinked to original sources
PubMed1984

Beta 1 - beta 2 blocking activity of propranolol and metoprolol in the unanaesthetized genetically hypertensive and normotensive rat.

The beta-antagonistic activity of propranolol and metoprolol has been evaluated, in terms of inhibition of isoproterenol effects, "in vitro" (isolated right atria and tracheae) and "in vivo" in unanaesthetized normotensive and spontaneously hypertensive rats (SHR). Metoprolol resulted 13 - 6.4 - 14 times more cardioselective than propranolol in the three aforementioned experimental models, respectively. SHR, because of its decreased baroceptor sensitivity to trigger the tachycardic reflex, proves a good model for the evaluation of beta 1 antagonistic activity of "cardioselective" beta- blockers, which could be underevaluated in the normotensive rat. Moreover, the agonistic activity of isoproterenol has been compared in normo and hypertensive rats in order to ascertain whether the different number of beta 1 receptors in the two strains could influence the biological response to their stimulation and/or or blockade.

Animals↗
PubMed1979

Bronchodilator activity in vivo and in vitro of four 13,14-didehydro-PGE2 analogues.

The bronchodilator activity of four analogues of PGE2: 13,14-didehydro-PGE2 (I), 20-methyl-13,14-didehydro-PGE2 (II), 16 S-methyl-13,14-didehydro-PGE2 (III) and 16 R-methyl-13,14-didehydro-PGE2 (IV) was studied in vivo and in vitro. The potency of III and IV when administered by aerosol to conscious guinea pigs was four times that of PGE2 in protecting against histamine-induced convulsion; I and II were less active. Compound III administered by aerosol to anaesthetized guinea pigs was six times more potent than PGE2 in protecting against i.v. histamine-induced increase of intractracheal pressure and the effect was longer-lasting. All the compounds caused relaxation of carbachol-induced tone in isolated guinea pig tracheal strips.

Anesthesia↗
PubMed1975

PGE2:PGE-2:.

The biological activities of 8,12-diiso-PGE2 (ent-11,15-epi-PGE2), PGE2 and PGF2alpha have been compared in a series of pharmacological preparations intended to differentiate between F and E type of activity. Similar to PGF2alpha but unlike PGE2, 8,12-diiso-PGE2 increased the tone of isolated smooth muscle preparations of guinea pig trachea, guinea pig colonic circular layer, rabbit Fallopian tubes. The stimulation effect of 8,12-diiso-PGE2 and PGF2alpha on visceral smooth muscle was also shown in vivo: the two drugs were in all instances able to increase the miogenic activity and tone of rabbit uterus in situ, while these were depressed by PGE2. 8,12-diiso-PGE2 decreased pulmonary compliance and increased pulmonary vascular resistance in the anaesthetized cat; PGE2 always decreased pulmonary vascular resistance, while leaving pulmonary compliance unaltered. The possibility is suggested that 8,12-diiso-PGE2 acts on PGF receptor in different tissues.

Animals↗