Suppression of isoprenaline-induced increase in plasma renin concentration by vasoconstrictors in rats with nonfunctioning Macula densa.
The mechanism of the increase in plasma renin concentration caused by the beta-sympathomimetic agent isoprenaline has been further investigated. Rats were pretreated by occluding the left renal artery for 2 hrs, thus rendering the macula densa cells of this kidney nonfunctioning. After contralateral nephrectomy infusion of isoprenaline (1.5 mug/kg min) still caused a strong increase in plasma renin concentration. This increase was significantly suppressed by simultaneous infusion of angiotensin II (1.0 mug/kg min). The alpha-sympathomimetic amine phenylephrine (60 mug/kg min) or octapressin (10 mU/kg min). The results exclude any mediator-role of the macula densa receptors in the isoprenaline-induced release of renin. The possibility of a stimulation of renin release via the baroreceptors or a direct "secretomotoric" action of isoprenaline is discussed.
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D003250:Constriction; D005259:Felypressin / Q000494:pharmacology; D007545:Isoproterenol / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007668:Kidney / Q000378:metabolism; D007684:Kidney Tubules / Q000502:physiology*; D007686:Kidney Tubules, Distal / Q000166:cytology / Q000502:physiology*; D008297:Male; D009392:Nephrectomy; D010656:Phenylephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects; D012077:Renal Artery / Q000502:physiology; D012083:Renin / Q000097:blood* / Q000378:metabolism; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D011941:Receptors, Adrenergic; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D010656:Phenylephrine; D005259:Felypressin; D012083:Renin; D007545:Isoproterenol