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G Viti

Publications and source records attributed to G Viti.

6 recordsLinked to original sources
PubMed1992

Activity of peptide and non-peptide antagonists at peripheral NK1 receptors.

We investigated the affinity of several tachykinin antagonists reportedly selective for NK1 receptors at various tachykinin receptors and NK2 receptors subtypes. The four antagonists tested were: L 668,169, Spantide II, Ac-Thr-DTrp(for)-Phe-NMeBzl (FR 113680) and the novel nonpeptide antagonist (+/-)-CP-96,345. The four antagonists were found to be effective against NK1 receptor-mediated responses in the guinea-pig ileum with the following rank order of potency (pKB values in parentheses): (+/-)-CP-96,345 (8.11) greater than Spantide II (7.08) greater than FR 113680 (6.61) greater than or equal to L 558,169 (6.44). (+/-)-CP-96,345, Spantide II and FR 113680 were distinctly more potent at NK1 receptors than at NK2 receptors (NK2A in the rabbit pulmonary artery, NK2B in the hamster trachea). L 668,169 antagonized neurokinin A-induced contractions in the hamster trachea with an affinity similar (pKB value 6.16) to that found in the guinea-pig ileum for NK1 receptors (pKB value 6.44). All antagonists were inactive at NK3 receptors of the rat portal vein. In a second series of experiments, the affinities of test antagonists for NK1 receptors in the guinea-pig ileum were compared to those for NK1 receptors in the guinea-pig vas deferens, the rabbit jugular vein and the rat urinary bladder. For each antagonist, the affinity measured in the guinea-pig vas deferens and the rabbit jugular vein was comparable to that found in the guinea-pig ileum. In the rat urinary bladder, (+/-)-CP-96,345 was about 100 times less potent in blocking NK1 receptor-mediated contractions than in the guinea-pig ileum.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

Direct evidence that capsaicin-induced plasma protein extravasation is mediated through tachykinin NK1 receptors.

The involvement of tachykinin NK1 receptors in the plasma protein extravasation (measured by the Evans blue leakage technique) produced by intravenous administration of capsaicin was investigated in the urinary bladder and trachea of anesthetized rats. Capsaicin-induced plasma extravasation was markedly inhibited by (+/-)-CP-96,345, a novel and potent non-peptide antagonist of tachykinin NK1 receptors. The same dose of (+/-)-CP-96,345 markedly inhibited the plasma protein extravasation induced by the selective NK1 receptor agonist, [Sar9]substance P sulfone, but had no effect on the response to histamine.

Anesthesia↗
PubMed1991

Role of NK1 tachykinin receptors in thermonociception: effect of (+/-)-CP 96,345, a non-peptide substance P antagonist, on the hot plate test in mice.

We have tested the ability of (+/-)-CP 96,345, a novel nonpeptide substance P (SP) antagonist, to block the aversive behaviour induced by intrathecal (i.t.) administration of SP and to induce thermal antinociception in mice. (+/-)-CP 96,345 administered i.t. or i.p. selectively blocked the effect of i.t. SP while leaving the response to i.t. bombesin unaffected. At the same dose proven effective against i.t. SP, (+/-)-CP 96,345 produced thermal analgesia in the hot plate test (52 degrees C). Using isolated organs for bioassay evaluation of activity at tachykinin receptor, (+/-)-CP 96,345 was found to be a potent (pA2 8.11, c.l. 7.9-8.3) and competitive NK1 receptor antagonist while it was devoid of activity at NK2 or NK3 receptors. These findings provide clear indication for the participation of SP, via NK1 receptors, in thermal nociception.

Animals↗
PubMed1991

New dibenzothiadiazepine derivatives with antidepressant activities.

A new series of 11-[(aminoalkyl)carbonyl] derivatives of 6,11-dihydrodibenzo[c,f][1,2,5]thiadiazepine 5,5-dioxide (10-39) were synthesized and evaluated for potential antidepressant activity in the apomorphine-induced hypothermia (Apo 16) test. Effects on reserpine-induced hypothermia and toxicity for the most potent antagonists of Apo 16 hypothermia were also studied. Structure-activity relationships are reported. Anticholinergic effects were evaluated for compound 12, identified as the most potent and least toxic in this series, by assessing physostigmine lethality. Compound 12 was also subjected to X-ray analysis.

Animals↗
PubMed1979

Exocrine pancreatic function after total gastrectomy.

The secretion of bicarbonate, lipase, and chymotrypsin into the duodenum in response to exogenous stimulation with secretin, 1 CU/kg-h, plus caerulein, 100 ng/kg-h, was investigated in 12 patients, on an average, 20.7 months after total gastrectomy and in 14 control subjects. The secretion of bicarbonate and lipase was significantly lower in patients than in controls. The reduction in outputs compared with the control values was 47.9%, 38.7%, and 24.2% respectively for bicarbonate, lipase, and chymotrypsin. Eight of the 12 patients (67%) had steatorrhoea. No significant correlation was found between this parameter and lipase output. It is concluded that the exocrine pancreatic function is impaired in the majority of patients subjected to total gastrectomy. The impairment, which particularly affects bicarbonate and lipase, is generally mild to moderate.

Adult↗