Influence of bromocriptine on free amino acids in the kidneys and heart of the rat.
The effects of bromocriptine, sulpiride or their combination on free amino acids in the kidneys and the heart after acute and chronic treatment of rats were investigated, using an automatic LKB Amino Acid Analyzer. Bromocriptine at a single dose of 4 or 10 mg/kg (i.p.) did not affect the level of any amino acid; however, at a dose of 20 mg/kg it significantly elevated the content of taurine in the kidney from 7.00 +/- 0.30 to 9.70 +/- 0.1 and in the heart from 22.9 +/- 1.7 to 30 +/- 1.2 mumol/g wet tissue (P less than 0.05, N = 7). It also increased glutamic acid in the heart from 3 +/- 0.1 to 4.5 +/- 0.25 mumol/g wet tissue (P less than 0.05, N = 7). Chronic oral treatment of rats with bromocriptine (20 mg.kg-1.day-1) for 5 weeks significantly elevated the level of taurine in the kidney from 7.2 +/- 0.3 (control) to 11.1 +/- 0.90 and in the heart from 23.1 +/- 1.7 to 38.8 +/- 1.8 mumol/l g wet tissue. It also increased cardiac glutamic acid content from 3 +/- 0.1 to 4.8 +/- 0.24 mumol/g wet tissue (P less than 0.01, N = 7). Concurrent administration of sulpiride (20 mg/kg) significantly suppressed bromocriptine-induced increases in taurine and glutamic acid in both organs, suggesting an activation of D2 receptors by bromocriptine. Due to the similarities between bromocriptine and the affected amino acids in renal and cardiac actions, it is suggested that mobilization of taurine and glutamic acid may at least in part contribute towards bromocriptine-induced renal and cardiac actions.
Ageel
A M
AM
Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia.
el Tahir
K E
KE
Abu-Jayyab
A
A
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology*; D005971:Glutamates / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D013469:Sulpiride / Q000494:pharmacology; D013654:Taurine / Q000378:metabolism
D000596:Amino Acids; D005971:Glutamates; D013654:Taurine; D001971:Bromocriptine; D013469:Sulpiride