title: Increased excretion of taurine, hypotaurine and sulfate after hypotaurine loading and capacity of hypotaurine metabolism in rats.
abstract: Hypotaurine was intraperitoneally injected into rats and urinary taurine, hypotaurine and sulfate were determined. Taurine excretion increased dose-dependently when 1 to 7 mmol of hypotaurine per kg of body weight was administered. The total excretion and the increased excretion (difference of those before and after the loading) were 2328 +/- 219 and 1948 +/- 153 mumol per kg of body weight per day, respectively, at 7 mmol of hypotaurine loading. Hypotaurine excretion was negligible in the normal rat urine. However, it increased when hypotaurine was loaded. Hypotaurine excretion at 7 mmol of hypotaurine loading was 2282 +/- 258 mumol per kg per day. These results indicate that the capacity of hypotaurine oxidation to taurine in rats is more than 2 mmol per kg per day under the present experimental conditions. Sulfate excretion increased significantly when more than 3 mmol of hypotaurine per kg of body weight was injected. When 5 and 7 mmol of hypotaurine was loaded, the increased excretion of sulfate was 619 +/- 205 and 632 +/- 118 mumol per kg per day, respectively. It was confirmed that in vitro incubation of hypotaurine and 2-oxoglutarate with rat liver homogenate results in the formation of L-glutamate and sulfate. Present findings indicate that hypotaurine in vivo was mainly oxidized to taurine and that it was partly metabolized to sulfate via transamination reaction.
authors.affiliation: Department of Biochemistry, Okayama University Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Ubuka
authors.forename: T
authors.initials: T
authors.lastname: Abe
authors.forename: K
authors.initials: K
authors.lastname: Yukihiro
authors.forename: M
authors.initials: M
authors.lastname: Tomozawa
mesh_terms: D000818:Animals; D007700:Kinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013431:Sulfates / Q000652:urine*; D013654:Taurine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics / Q000652:urine*; D013997:Time Factors
chemical_list: D013431:Sulfates; D013654:Taurine; C003949:hypotaurine