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Biomedical subjects

G M Frigo

Publications and source records attributed to G M Frigo.

At least 73 records · Page 4Linked to original sources
PubMed1980

Effects of metopimazine on gastro-intestinal and biliary tract smooth muscle in vitro.

The effects of the phenothiazine derivative metopimazine on the spontaneous or induced activities of guinea-pig isolated stomach and of the rabbit biliary and intestinal tracts were studied. A predominant inhibitory effect was observed except for the circular muscle layers of the duodenum and colon where activation appeared. Evidence from in vitro experiments suggest that metopimazine exerts an inhibitory action partly through a direct effect on smooth muscle cells and partly by reducing stimulated acetylcholine release (at least in the stomach). Finally the involvement of a non-adrenergic, non-cholinergic inhibitory system is postulated.

Acetylcholine↗
PubMed1979

Modification of phenytoin clearance by valproic acid in normal subjects.

1 The effect of valproic acid on the distribution and elimination kinetics of intravenously administered phenytoin has been investigated in eight normal volunteers. 2 In each of the subjects studied the volume of distribution of phenytoin increased significantly during treatment with sodium valproate (1200 mg daily for 7 days). 3 Phenytoin clearance was markedly increased in presence of valproic acid as compared to control values (0.52 +/- 0.17 v 0.38 +/- 0.11 ml min-1 kg-1 respectively, P less than 0.02). 4 It is suggested that the increase of the volume of distribution and of the serum clearance are secondary to displacement of phenytoin from plasma protein binding sites by valproic acid.

Adult↗
PubMed1978

Disposition of sodium valproate in epileptic patients.

1 Serum levels of valproic acid have been determined at fixed intervals after the administration of single oral and intravenous doses (800 mg) to six epileptic patients receiving chronic treatment with other antiepileptic drugs. 2 Serum levels declined monoexponentially shortly after the intravenous administration. Biological half-lives averaged 9.0 +/- 1.4 h (s.d.). Volumes of distribution were 0.175 +/- 0.025 l/kg. There was a statistically significant negative correlation between volumes of distribution and serum half-lives (P less than 0.005). 3 After oral doses serum levels rose rapidly to peak values within 0.5--2 h. Biological availability was 96 +/- 9%. 4 Comparison with a previous study performed according to the same protocol in healthy volunteers showed significantly increased volumes of distribution and rates of elimination in the patients. Total serum clearance was 85% higher in the patients as compared to the healthy subjects (P less than 0.001). Possible explanations for these findings are discussed.

Adult↗
PubMed1977

Effects of pentazocine on the intestine and biliary tract of the rabbit in vitro.

Pentazocine impairs peristaltic activity and relaxes longitudinal muscle in the colon and in the ileum. The circular coat is excited in the colon, while in the ileum pentazocine exhibits both excitatory and inhibitory effects depending on the concentration employed. Pentazocine does not exert a spasmogenic effect in the smooth muscle of terminal bile duct but instead reduces the electrically-induced contraction. The effect of pentazocine does not seem to involve endogenous acetylcholine or catecholamine release.

Acetylcholine↗
PubMed1977

Comparison of quinidine plasma concentration curves following oral administration of some short- and long-acting formulations.

1 The time-course of quinidine plasma concentrations and selected kinetic parameters were studied in healthy male volunteers given single oral doses of four different quinidine formulations. Comparison was made with quinidine sulphate in a rapidly dissolving form. 2 Plasma half-lives did not significantly differ among treatments. 3 Quinidine polygalacturonate appears to be equivalent to quinidine sulphate in respect to both the absorption and elimination kinetics. When both quinidine bisulphate (Kinidin Durules) and quinidine arabogalactansulphate (Longacor) were administered plasma levels peaked significantly later than after quinidine sulphate. However, while the former seems to be absorbed to the same extent as quinidine sulphate, the latter exhibits lower bioavailability in respect to all other preparations.

Administration, Oral↗
PubMed1975

Effect of diazepam on unstimulated and on stimulated gastric secretion.

The effect of intravenous diazepam on unstimulated and on pentagastrin-stimulated gastric secretion has been studied in normal subjects. No significant effect of diazapam was found on pentagastrin-stimulated gastric secretion. Unstimulated secretion was reduced by diazepam. This action of diazepam may be useful in peptic ulcer therapy.

Adult↗