Renin secretion by fetal lamb kidneys in vitro.
We studied the content and secretion of renin by renal cortical slices obtained from ovine fetuses at 0.62-0.77 gestation (n = 5 immature) and at 0.84-1.00 gestation (n = 5 mature). Renin content of fresh slices and renin secretion after the incubation of slices in Robinson's medium with or without isoproterenol or dibutyryl (DB) adenosine 3',5'-cyclic monophosphate (cAMP) (10(-4)-10(-8) M) were measured. Renin content of immature fetal kidneys (ng.ml homogenate-1.h-1.mg-1) and basal renin secretion rate [ng (ANG I/h).mg tissue-1.h incubation-1] were 24.3 +/- 3.0 and 1.4 +/- 0.4, respectively. Both of these values were significantly lower (P less than 0.02) than the corresponding results obtained with mature fetal kidneys (67.0 +/- 4.5 and 3.4 +/- 0.5). Renin content and basal secretion rates were strongly correlated (r = 0.78, P less than 0.01). The addition of isoproterenol or DBcAMP induced a significant increase in renin secretion only when incubated with slices from mature fetuses. We conclude that there is a deficit in the beta-adrenoceptor-mediated renin release distal to cAMP formation in immature fetuses, which may be related to low renal content of renin at this stage of development.
Rawashdeh
N M
NM
Department of Physiology, Jordan University of Science and Technology, Irbid.
Rose
J C
JC
Kerr
D R
DR
D000704:Analysis of Variance; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D005333:Fetus / Q000378:metabolism*; D005865:Gestational Age; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D007606:Juxtaglomerular Apparatus / Q000196:embryology; D007668:Kidney / Q000187:drug effects* / Q000196:embryology; D012083:Renin / Q000378:metabolism*; D012756:Sheep
D003994:Bucladesine; D012083:Renin; D007545:Isoproterenol