Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1995-3-31
pubmed:abstractText
The luminal membrane of collecting duct cells, especially the intercalated cells, is normally exposed to active kallikrein. This is the consequence of the specific localization of this renal enzyme in the connecting tubule cells and its principal route of secretion being into the tubular lumen. It is conceivable that kallikrein acts downstream on a transporter involved in distal bicarbonate handling. To investigate this possibility, we estimated bicarbonate concentration and measured kallikrein amidolytic activity in urine fractions collected after a classical stop-flow experiment in rabbits. A highly significant inverse correlation was found between these parameters (r = -0.94, p < 0.001) in the peak kallikrein fractions. Neither sodium nor potassium concentration were correlated to kallikrein. This suggests that the physiological role of renal kallikrein may be to regulate extracellular fluid pH by inhibiting collecting duct bicarbonate secretion. To test the hypothesis that tubular fluid kallikrein activity and bicarbonate secretion are causally related, we developed a novel in vivo stop-flow injection model ('orthograde stop-flow'). A hog-kallikrein containing solution (0.5 microgram/ml) was injected through the abdominal aorta into the renal tubular system of one kidney of barbiturate-anesthetized rats, while the renal blood supply was interrupted. The ureter was then occluded and renal blood perfusion reinitiated. After a 2-min contact time five 125-microliters urine fractions were collected. Bicarbonate secretion was clearly detected in the second and third fractions (i.e. those coming from the collecting ducts) of the control animals, which had received only the vehicle. There was no bicarbonate secretion peak in the corresponding urine fractions collected from kallikrein-injected animals.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1011-6524
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
301-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Evidence for an inhibitory effect of kallikrein on collecting duct bicarbonate secretion in rats and rabbits.
pubmed:affiliation
Physiologisches Institut, Ludwig-Maximilians-Universität zu München, Deutschland.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't