Response of guanylate cyclase to atrial natriuretic factor in epithelial cells of the frog choroid plexus.
This study shows that the choroid plexus of Rana esculenta contains a guanylate cyclase particulate (GCp), similar to that identified in Mammalia, that is quite sensitive to the atrial natriuretic factor (ANF). The cytochemical tests for GCp show that ANF increases the enzymatic reaction products. Deposits are observed on the apical portion, at the basal level and along the lateral edges of the epithelial cells, with the exclusion of some intercalary epithelial cells with reaction-lacking microvilli. In particular, ANF seems to intensely stimulate the GCp activity along the lateral membranes of the epithelial cells delimiting enlarged intercellular spaces, which are probably dilated for the transport of water and solutes. These data confirm the osmoregulatory role of the hormone and its control of cephalorachidian liquid composition.
Tei
S
S
Institute of Comparative Anatomy, University of Perugia, Italy.
Vagnetti
D
D
Secca
T
T
Santarella
B
B
Roscani
C
C
Farnesi
R M
RM
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D016764:Cell Polarity / Q000187:drug effects; D002831:Choroid Plexus / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D006152:Cyclic GMP / Q000096:biosynthesis*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology; D006162:Guanylate Cyclase / Q000378:metabolism*; D006651:Histocytochemistry; D011893:Rana esculenta / Q000033:anatomy & histology / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D006152:Cyclic GMP