Anatomic pairing of afferent arterioles and renin cell distribution in rat kidneys.
Close afferent arteriolar (AA) connectivity is a prerequisite for hemodynamic interaction between superficial rat nephrons. Studies were conducted in rat, mouse, rabbit, and human renal vasculatures obtained by an HCl maceration-microdissection technique to document the extent of AA connectivity. In rat kidneys, we assessed the possibility for a slow component of internephron coupling, as reflected by arteriolar renin cell distribution after specific immunostaining for renin. In the four species examined, 51% (human) to 60% (mouse) of total AA populations were organized as vascular units consisting of mostly two AA sharing a common origin and a connecting arterial segment. In rat AA pairs, branch lengths were significantly correlated, suggesting coordinated arteriolar growth. The sum of AA branch lengths averaged 278 +/- 6 microns. Rat arteriolar renin status, ranging from no renin cells to renin-recruited midafferent arterioles, distributed in a significantly nonrandom fashion within AA pairs, and 52% of the pairs had equal renin status. Hence, AA pairing is a consistent anatomic characteristic of mammalian kidneys and may constitute an optimal vascular design for hemodynamic as well as endocrine interactions.
Casellas
D
D
Groupe Rein et Hypertension, Hôpital St. Charles, Montpellier, France.
Dupont
M
M
Bouriquet
N
N
Moore
L C
LC
Artuso
A
A
Mimran
A
A
D000818:Animals; D001160:Arterioles / Q000033:anatomy & histology* / Q000737:chemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D007668:Kidney / Q000098:blood supply*; D008297:Male; D051379:Mice; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D012083:Renin / Q000032:analysis*
D012083:Renin