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J Roba

Publications and source records attributed to J Roba.

At least 37 records · Page 2Linked to original sources
PubMed1983

Topographical distribution of the secretin- and VIP-stimulated adenylate cyclase system in the heart of five animal species.

Adenylate cyclase stimulation by secretin and VIP was compared to the effect of glucagon, D,L-isoproterenol, Gpp[[NH]p, and NaF in atria and ventricles from rat, guinea pig, rabbit, dog and Cynomolgus monkey. In rat ventricular membranes, secretin was a better stimulant than VIP and was as active as D,L-isoproterenol. In rat auricular membranes both peptides were inactive. In guinea pig and rabbit heart membranes (ventricular and auricular) VIP and secretin were inactive. In dog and monkey atria, VIP stimulation of adenylate cyclase was comparable to that of D,L-isoproterenol, secretin being inactive. In dog ventricles, VIP was less efficient than D,L-isoproterenol, secretin being inactive. In monkey ventricles, by contrast, VIP was slightly more efficient than D,L-isoproterenol, secretin having a small effect only in left ventricles. The present results established a clear difference between animal species with respect to the efficacy of the peptides of the secretin/VIP family: the presence of "secretin-preferring" receptors in rat heart contrasted with the presence of "VIP-preferring" receptors in dog and monkey heart. Our results in dog and monkey hearts suggest that VIP might be a candidate for a physiological control of heart function.

Adenylyl Cyclases↗
PubMed1983

Anticonvulsant activity of milacemide.

The anticonvulsant activity of a new drug, milacemide (2-(pentylamino)-acetamide), has been studied in animal models of convulsions like those induced by bicuculline, pentylenetetrazol, picrotoxin, strychnine, inhibitors of GABA synthesis as 3-mercaptopropionic acid, allylglycine, isoniazid and thiosemicarbazide and electroshock. Milacemide is particularly effective in inhibiting the convulsions induced by bicuculline. The ED50 is 5.7 mg/kg by oral route and the activity lasts for more than 48 hr. It is less active against pentylenetetrazol and only marginally active against electroshock. It has not be found active against the other types of convulsions. Milacemide has a low toxicity (LD50: 2585 mg/kg in the mouse) and alters the behaviour of mouse, rat and monkey, only at high doses (greater than or equal to 1000 mg/kg). Milacemide seems to be specially free of sedative potential.

Acetamides↗
PubMed1981

Comparative effects of alpha-methyldopa, propranolol and hydralazine therapy on cardiac adenylate cyclase activity in normal and spontaneously hypertensive rats.

Normotensive (WKY) and spontaneously hypertensive (SHR) male rats were treated orally, one week after weaning and for 9 weeks, with alpha-methyldopa (100 mg/kg per day), propranolol (30 mg/kg per day) or hydralazine (10 mg/kg per day). Untreated WKY and SHR rats served as controls. The development of hypertension in SHR rats were attenuated by treatment but none of the drugs was able to restore the impairment in isoproterenol, secretin and glucagon responsiveness of cardiac adenylate cyclase activity which is characteristic of these animals. In heart membranes from both WKY and SHR rats, alpha-methyldopa treatment increased the number of beta-adrenoceptors by 20-32% and the maximal response of adenylate cyclase activity to isoproterenol and glucagon by 20-34%. By contrast, the beta-blocker propranolol was ineffective on these parameters. The results obtained are consistent with the hypothesis that the change in adenylate cyclase seen in SHR rats is genetic in origin and is not a consequence of hypertension.

Adenylyl Cyclases↗
PubMed1977

Effects of suloctidil on lipid metabolism in experimental animals.

A novel potent vasoactive agent, 1-(4-isopropyl-thiophenyl)-2-n-octylaminopropanol (suloctidil, Sulocton), lowers excess of plasma cholesterol and tends to normalize the plasma hyperbetalipoproteinemia of Rhesus monkeys fed a high-cholesterol, high-fat diet. The drug shows an inhibitory effect on the cholesterol biosynthesis in rat liver homogenates.

Animals↗
PubMed1976

Antiplatelet and antithrombogenic effects of suloctidil.

Platelet aggregation induced in mice or rats by i.v. ADP can be antagonized by oral administration of suloctidil. This effect on platelet behaviour appears to be sufficient to reduce the rate of thrombotic occlusion of the femoral artery in the dog and to protect the rat against occurrence of thrombophlebitis.

Adenosine Diphosphate↗
PubMed1976

In vivo antispasmodic activity of Sulcotidil.

Suloctidil was tested in vivo for its antispasmodic activity on peripheral and cerebral circulations. In the perfused dog hind limb preperation, suloctidil was found to inhibit after 2 and 5 min, the vasospasm induced by norepinephrine or angiotensin; at equal dose, and at the game time intervals, it was more potent than cinnarizine and papaverine. BaCl(2) induced spasms of the pial arterial of the rabbit were also rapidly alleviated by i.a. suloctidil (3.5 mug/kg or more), in conditions where papaverine and vincamine were inactive.

Angiotensin II↗