Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Renal proximal tubular buffer-(glycodiazine) transport (1975)
    Springer
    Pflügers Archiv 357 (1975), S. 149-163 
    Details
    ISSN: 1432-2013
    Keywords: Renal Tubule ; H+ Transport ; Sodium Dependence ; Carbonic-Anhydrase Inhibitors ; Adaptation (Acid Base Balance)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using the stop flow microperfusion technique with simultaneous capillary perfusion the secretory rate of H+ ions in the proximal tubule was evaluated by measuring the level flow reabsorption as well as the static head concentration difference of3H labelled glycodiazine. At ambient glycodiazine concentration of 21 mmol/l the level flow reabsorption is in the same range as that of bicarbonate. In the early proximal loops the reabsorption is 20% greater than in the late proximal loops. The carbonic anhydrase inhibitors acetazolamide and 3,4-methylenedioxyphenyl-sulfonamide (both 10−4 M) as well as furosemide (10−3 M) inhibit the glycodiazine reabsorption 43%, 27% and 22% respectively. Thiocyanate (2 · 10−2 M), however, exerted only an insignificant inhibition (12%). When Na+ in the ambient perfusion solutions was replaced by Li+ or choline+ the glycodiazine transport was strongly reduced. Ouabain (5 · 10−2 M) inhibited too, but amiloride (10−3 M) had no effect on glycodiazine transport. The glycodiazine transport was 28% reduced in metabolic alkalosis and to a smaller although significant extent (17%) in metabolic acidosis; it was unchanged in chronic hypercapnia. In chronic K+ depletion the glycodiazine reabsorption was accelerated by 12% only in the early proximal loops. Chronic parathyroidectomy as well as acute substitution with parathyroid hormone had no effect on the glycodiazine absorption. The main conclusions are: Proximal H+ transport proceeds with suitable buffers. Although independent of HCO3 − and carbonic anhydrase, it could be partially inhibited by CA inhibitors. H+ transport is supposed to proceed as countertransport with Na+ ions. In chronic alkalosis the H+ transport is reduced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585971
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Sodium reabsorption in the papillary collecting duct of rats (1979)
    Springer
    Pflügers Archiv 379 (1979), S. 49-52 
    Details
    ISSN: 1432-2013
    Keywords: Renal collecting duct ; Na+ reabsorption ; Adrenalectomy ; Acetazolamide ; Amiloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Using the shrinking droplet method and simultaneous perfusion of the peritubular capillaries the isotonic reabsorption of Ringer's solution from the papillary collecting ducts was measured. Under control conditions the volume reabsorption from the papillary collecting ducts wasJ v±SE=2.6±0.1 · 10−5 cm3 · cm−2 · s−1. In rats which were on low Na+ diet,J v increased to 127%, and in adrenalectomized animals it decreased to 34% of the control value. Three hours after application of aldosterone in the adrenalectomized animalsJ v was partially restored to 63% of control rats. Amiloride 10−4 M, added to the luminal perfusate, produced a strong inhibition ofJ v (to 32% of control). Acetazolamide, 10−4 M, added to both perfusates, reducedJ v very strongly (to 40% of control), while omission of bicarbonate reduced it only to 77% of control. Acetazolamide, added to bicarbonate-free perfusates, did not result in a significant further reduction ofJ v. The data indicate that the Na+ reabsorption from the papillary collecting duct is controlled by mineralocorticoids. Furthermore, they suggest the existence of two transport mechanisms in the luminal cell membrane: 1. An amiloride-sensitive entry step and 2. an entry step via a Na+−H+-countertransport mechanism, the latter being less important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00622904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...