Adenosine, a regulator of cardiovascular development and renal function, constricts renal afferent
arterioles by inducing intracellular Ca2+ ([Ca2+]i) elevation in smooth muscle cells (SMCs) via
activation of its cognate A1 receptors (A1Rs). Mechanisms that underlie A1R-dependent [Ca2+]i
elevation in renal vascular SMCs are not fully resolved. Whether A1R expression and function in
preglomerular microvessels are dependent on postnatal kidney maturation is also unclear. In this
study, we show that selective activation of A1Rs by 2-chloro-N6-cyclopentyladenosine (CCPA) does
not stimulate store-operated Ca2+ entry in afferent arterioles isolated from neonatal pigs. However,
CCPA-induced [Ca2+]... More
Adenosine, a regulator of cardiovascular development and renal function, constricts renal afferent
arterioles by inducing intracellular Ca2+ ([Ca2+]i) elevation in smooth muscle cells (SMCs) via
activation of its cognate A1 receptors (A1Rs). Mechanisms that underlie A1R-dependent [Ca2+]i
elevation in renal vascular SMCs are not fully resolved. Whether A1R expression and function in
preglomerular microvessels are dependent on postnatal kidney maturation is also unclear. In this
study, we show that selective activation of A1Rs by 2-chloro-N6-cyclopentyladenosine (CCPA) does
not stimulate store-operated Ca2+ entry in afferent arterioles isolated from neonatal pigs. However,
CCPA-induced [Ca2+]i elevation is dependent on phospholipase C and transient receptor potential
cation channel, subfamily C, member 3 (TRPC3). Basal [Ca2+]i concentration was unchanged in
afferent arterioles isolated from newborn (0-day-old) pigs when compared with their 20-day-old
counterparts. By contrast, CCPA treatment resulted in significantly larger [Ca2+]i in afferent arterioles
from 20-day-old pigs. A1R protein expression levels in the kidneys and afferent arterioles were
unaltered in 0-day- versus 20-day-old pigs. However, TRPC3 channel protein expression level was ~
92 and 78% higher in 20-day-old pig kidneys and afferent arterioles, respectively. These data
suggest that activation of A1Rs elicits receptor-operated Ca2+ entry in porcine afferent arterioles, the
level of which is dependent on postnatal maturation of TRPC3 channels. We propose that TRPC3 37
channels may contribute to the physiology and pathophysiology of A1Rs.