Inter-organ relation between salivary gland and kidney in lithium excretion. IV. Saturation of inhibitory effect of NaCl on ductal reabsorption of Li+ in beagle dogs.
The inhibitory effect of NaCl coadministration on the reabsorption of Li+ in the salivary ducts and the renal tubules was investigated in beagle dogs. Following the bolus intravenous administration of LiCl (0.145 meq/kg), 50 ml of NaCl solution (100, 200 meq/l) was administered orally each hour, and parotid saliva (Pr) and mandibular-sublingual saliva (MS) were collected under the continuous stimulation of salivation with citric acid. The renal clearance of Li+ increased with the increased concentration of administered NaCl solution. This could be a result of the competitive inhibition of the tubular reabsorption of Li+ by Na+. The salivary clearance of Li+ also tended to increase by the administration of NaCl. These results suggest the existence of a reabsorption process of Li+ in the salivary glands similar to that in the renal tubule. However, when the administered NaCl was increased from 100 to 200 meq/l, the renal clearance was further increased, but the salivary clearance was not. This suggests that the transport capacity of Li+ reabsorption is relatively small in the salivary glands, compared with that in the renal tubule, and that the inhibitory effect of NaCl on Li+ reabsorption had already reached a maximum level when 100 meq/l NaCl was administered.
Higuchi
J
J
Department of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Nagoya City University, Japan.
Watanabe
J
J
Hayashi
Y
Y
Yuasa
H
H
D000042:Absorption / Q000187:drug effects; D000284:Administration, Oral; D000818:Animals; D004285:Dogs; D007275:Injections, Intravenous; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism*; D018021:Lithium Chloride / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D008297:Male; D012469:Salivary Glands / Q000187:drug effects / Q000378:metabolism*; D012965:Sodium Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D014018:Tissue Distribution
D012965:Sodium Chloride; D018021:Lithium Chloride