Hypothetical interpretation of the calcium paradox in renin secretion.
Most renin-positive cells of the preglomerular arteriole are intermediate in morphological appearence between smooth muscle cells and epithelioid cells. Intermediate cells contain, in addition to secretory granules, contractile proteins arranged as a sublemmal network. The paradoxical (inhibitory) role of calcium in renin secretion is explained, on the basis of these findings, by an increased tone of the sublemmal network; this might impair the preexocytotic access of renin granules to the cell membrane.
Taugner
R
R
I. Physiologisches Institut, Universität Heidelberg, Federal Republic of Germany.
Nobiling
R
R
Metz
R
R
Taugner
F
F
Bührle
C
C
Hackenthal
E
E
D000818:Animals; D002118:Calcium / Q000502:physiology*; D007668:Kidney / Q000098:blood supply / Q000201:enzymology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008954:Models, Biological; D051381:Rats; D012083:Renin / Q000378:metabolism*
D012083:Renin; D002118:Calcium