Role of adrenoceptors in diphenylhydantoin-stimulated renin release.
We have previously shown that diphenylhydantoin (DPH)-stimulated renin release is mediated by, or requires the presence of, the renal nerves. In the present study, we examined the effects of adrenergic blockers in DPH-stimulated renin release in five groups of anesthetized dogs. In vehicle-treated dogs, DPH at a dose of 0.18 mg/kg-min increased renin secretion rate (RSR) from 56 +/- 14 to 269 +/- 60 and returned to 84 +/- 30 ng of angiotensin (ANG) l/hr-min (P less than 0.01, analysis of variance). In metoprolol-treated dogs, DPH produced no significant changes in RSR (90 +/- 28 to 144 +/- 67 to 100 +/- 51 ng of ANG l/hr-min). Likewise, in atenolol-treated dogs, RSR was 34 +/- 10 before, 59 +/- 15 during, and 23 +/- 8 ng of ANG l/hr-min after the infusion of DPH. In contrast, after pretreatment with ICI 118,551 (a beta 2 adrenoceptor antagonist), RSR was 37 +/- 9 before, 151 +/- 57 during, and 47 +/- 12 ng of ANG l/hr-min after the infusion of DPH (P less than 0.01). In phentolamine-treated dogs, RSR was 69 +/- 20 before, 295 +/- 53 during, and 95 +/- 17 ng of ANG l/hr-min after the infusion of DPH (P less than 0.01). Changes in renal blood flow, renal vascular resistance, and UNa V were in the same directions in all groups. These data suggest that DPH-stimulated renin release is mediated by beta 1 adrenoceptors since both beta 2 and alpha adrenoceptor antagonists have no effects on DPH-stimulated renin release.
Cadnapaphornchai
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Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201.
Kellner
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McDonald
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D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D001262:Atenolol / Q000008:administration & dosage; D004285:Dogs; D005260:Female; D007261:Infusions, Intra-Arterial; D008790:Metoprolol / Q000008:administration & dosage; D010672:Phenytoin / Q000008:administration & dosage; D011412:Propanolamines / Q000008:administration & dosage; D011941:Receptors, Adrenergic / Q000187:drug effects / Q000502:physiology*; D012083:Renin / Q000378:metabolism*
D011412:Propanolamines; D011941:Receptors, Adrenergic; D000804:Angiotensin II; C026777:ICI 118551; D001262:Atenolol; D010672:Phenytoin; D012083:Renin; D008790:Metoprolol