Carbonic anhydrase and urease: an investigation in vitro on the possibility of a synergic action.

The indirect interactions between the carbonic anhydrase (CA) and urease (UR) are investigated in the present work using rate determinations detected by combined potentiometric measurements. It is shown that, in accord with the mass-action law for the two enzyme catalyzed reactions, the two enzymes assume a synergic pattern: the increase in the rate of removal of CO2 from the solution facilitated by CA increases the rate of production of NH3 consequent from urea dissociation. The experimental system which has been set up to monitor these interactions consists of a potentiometric apparatus to follow the gaseous exchanges of CO2 and NH3 which take place from a buffered solution containing both CA and UR. The results of the present work are consistent with, and add a further support to the finding of Dodgson and Forster, who first demonstrated in vivo the existence of an indirect linkage between urea production and CA catalytic activity

ChemInform Abstract: Synthesis and Inhibitory Activity on Carbonic Anhydrase of Some New Sulpiride Analogues Studied by Means of a New Method.

The pharmacological activity of several new sulpiride analogues was studied by means of a new approach, based on a potentiometric technique with a pCO2 sensor, capable of detecting carbonic anhydrase inhibition at equilibrium conditions. This procedure gives results stated as percent of inhibition of enzymatic activity (IP, inhibitory power). To prove the reliability of the proposed approach and to study structure-activity relationships, several new molecules were synthesized and tested in comparison with the two sulpiride enantiomers. A possible inhibition mechanism is discussed in terms of experimental evidence obtained from the interactions between the molecular structures of the new synthesized compounds and carbonic anhydrase

Synthesis and inhibitory activity on carbonic anhydrase of some new sulpiride analogues studied by means of a new method.

The pharmacological activity of several new sulpiride analogues was studied by means of a new approach, based on a potentiometric technique with a pCO2 sensor, capable of detecting carbonic anhydrase inhibition at equilibrium conditions. This procedure gives results stated as percent of inhibition of enzymatic activity (IP, inhibitory power). To prove the reliability of the proposed approach and to study structure-activity relationships, several new molecules were synthesized and tested in comparison with the two sulpiride enantiomers. A possible inhibition mechanism is discussed in terms of experimental evidence obtained from the interactions between the molecular structures of the new synthesized compounds and carbonic anhydrase

Tramadol and Cycling: Is It the End of a "Painful" Relationship? An Insight From 60,802 Doping-Control Samples From 2012 to 2020.

To assess the prevalence of tramadol use among athletes from 2012 to 2020. All urine samples were collected from national and international in-competition doping-control tests that took place in Italy between 2012 and 2020. The analysis of the samples was performed by gas chromatography coupled with mass spectrometry with electronic ionization and acquisition in selected ion monitoring. The cutoff tramadol concentration was >50 ng/mL. Of the 60,802 in-competition urine samples we analyzed, 1.2% (n = 759) showed tramadol intake, with 84.2% (n = 637) of these coming from cyclists and 15.8% (n = 122) from other sports. In cycling, a strong and significant negative correlation was found (r = -.738; P = .003), showing a decrease of tramadol use compared with the other sports. The decrease in tramadol prevalence in cycling in the last years may be due to (1) the deterrent action of antidoping regulations and (2) the fact that tramadol may not have any actual ergogenic effect on performance