Cortical distribution of prostaglandin and renin in isolated dog glomeruli.

Abstract Cortical distribution of prostaglandin and renin in isolated dog glomeruli. This study was performed (1) to evaluate the ability of renal superficial (SP) and juxtamedullary (JM) isolated glomeruli to synthesize 6-keto-prostaglandin F 1α (6-keto-PGF 1α ) and prostaglandin E 2 (PGE 2 ) when stimulated with different doses of arachidonic acid (AA) and (2) to determine the differential effects that the formation of these prostaglandins may have on renin release. Renal SP and JM glomeruli were isolated separately from dog renal cortex using a passive sieving technique. Glomeruli were superfused within glass chambers with a Krebs Ringer solution and three different concentrations of AA. Effluent concentrations of 6-keto-PGF 1α (primary metabolite of PGI 2 ), PGE 2 , and renin were determined by radioimmunoassay. Synthesis of 6-keto-PGF 1α by SP glomeruli increased in a dose-dependent manner in response to the three increasing concentrations of AA. These three doses of AA also evoked proportional increments in the release of renin which were significantly correlated with the increases in 6-keto-PGF 1α . In contrast, PGE 2 synthesis was maximally stimulated by all doses of AA and was not correlated with renin release. In JM glomeruli, AA evoked the same pattern in the synthesis of 6-keto-PGF 1α and PGE 2 . However, renin release increased significantly only with the perfusion of the highest concentration of AA. These perfusion results show that SP and JM glomeruli have the same ability to synthesize 6-keto-PGF 1α and PGE 2 . However, renin release was significantly higher in SP than in JM glomeruli and correlated with 6-keto-PGF 1α synthesis. Distribution corticale de prostaglandines et de renine dans des glomerules isoles de chiens. Cette etude a ete effectuee (1) afin d'evaluer la capacite des glomerules isoles superficiels (SP) ou juxtamedullaires (JM) de synthetiser de la 6-keto-prostaglandine F 1α (6-keto-PGF 1α ) et de la prostaglandine E 2 (PGE 2 ) apres stimulation avec differentes doses d'acide arachidonique (AA) et (2) pour determiner les differents effets que la formation de ces prostanglandines pourrait entrainer sur le relargage de la renine. Des glomerules renaux SP et JM ont ete isoles separement a partir de cortex renal de chiens, en utilisant une technique de filtration passive. Les glomerules ont ete perifuses dans des chambres en verre avec une solution de Krebs-Ringer et trois concentrations differentes d'AA. Les concentrations effluentes de 6-keto-PGF 1α (metabolites primaires de PGI 2 ), de PGE 2 , et de renine ont ete determinees par dosage radioimmunologique. La synthese de 6-keto-PGF 1α par les glomerules SP s'elevait d'une facon dependante de la dose en reponse aux trois concentrations croissantes d'AA. Ces trois concentrations d'AA entrainaient egalement des augmentations proportionnelles dans le relargage de la renine, qui etaient significativement correlees avec les elevations de 6-keto-PGF 1α . A l'oppose, la synthese de PGE 2 etait stimulee de facon maximale par toutes les doses de AA, et n'etait par correlee au relargage de renine. Dans les glomerules JM, AA entrainait le meme type de synthese de 6-keto-PGF 1α et PGE 2 . Cependant, le relargage de renine ne s'elevait significativement que lors de la perfusion avec la plus forte concentration de AA. Ces resultats de perfusion montrent que les glomerules SP et JM ont la meme capacite de synthetiser de la 6-keto-PGF 1α et dans la PGE 2 . Cependant, le relargage de la renine etait significativement plus eleve dans les glomerules SP que JM et etait correle avec la synthese de 6-keto-PGF 1α .