Luminal acidification by the perfused XXXX @entity1971 .

@entity5838 @entity9755 @entity3884 @entity3791 @entity1372 @entity3157 @entity515 @entity520 @entity35 @entity1971
1. Acid secretion by the @entity35 @entity1971 was studied by microperfusion of the epididymal duct and by measuring the pH of the perfusate at a constant p @entity515 using a micro pH sensitive electrode. The rate of acidification was expressed as the rate of fall of intraluminal @entity3157 per cm duct per min.2. When the cauda epididymal duct was perfused with normal @entity3157 solution, the luminal @entity3157 concentration fell at a rate of 0.59 +/- 0.39 n-equiv cm(-1) min(-1) (mean +/- s.e.,n = 22).3. The rate of luminal acidification was independent of the perfusion rate but was dependent on the concentration of @entity3157 in the perfusion fluid. The rate of fall of luminal @entity3157 increased with increasing @entity3157 concentration and showed saturation at an intraluminal @entity3157 concentration of 25 @entity9755 /l.4. Acidification was abolished in the absence of intraluminal @entity1372 ions. This may suggest a linked @entity1372 reabsorption and @entity3884 ion secretion.5. Acidification of the luminal fluid was studied under different acid-base conditions. In animals undergoing @entity520 , the rate of acidification was enhanced, and conversely in animals undergoing @entity5838 , the rate was depressed.6. Intravenous infusion of @entity3791 into @entity35 at a dose rate of 20 mg/kg.hr markedly inhibited the acidification process. This effect was still observed in animals undergoing @entity520 . @entity3791 (10(-5)m) applied luminally was found to have no effect but higher concentration (10(-4)m) was found to inhibit acidification by 50%.7. The role of acidification of the epididymal fluid in sperm maturation was discussed.
