Affiliation:
1. From the Departments of Pediatrics (S.D., S.S.E.-D.) and Physiology (L.C., L.M.H.-B., G.P., J.D.I.), Tulane University School of Medicine, New Orleans, La.
Abstract
Abstract
—Kinins have been implicated in the hemodynamic adaptation to postnatal life. The present study examined the impact of bradykinin B
2
receptor (B
2
R) gene disruption on the postnatal changes in blood pressure (BP) and the susceptibility to early onset salt-sensitive hypertension in mice. B
2
R null (−/−) and wild-type (+/+) mice were fed normal (NS, 1% NaCl) or high (HS, 5% NaCl) salt diets during pregnancy. After birth, the pups remained with their mothers until they were weaned and were subsequently continued on the respective maternal salt intake until 4 months of age. The age-related changes at 3 and 4 months in tail-cuff BP and anesthetized mean arterial pressure at 4 months were not different in NS/B
2
R
−/−
and NS/B
2
R
+/+
mice. However, there was a mild increase in BP in NS/B
2
R
−/−
at 2 months versus NS/B
2
R
+/+
. In contrast, HS/B
2
R
−/−
mice manifested early onset and persistent elevations of tail-cuff BP (
P
<0.05) at 2, 3, and 4 months versus other groups. MAP was also higher in HS/B
2
R
−/−
than HS/B
2
R
+/+
, NS/B
2
R
−/−
, and NS/B
2
R
+/+
(91±3 versus 75±5, 74±2, and 70±2 mm Hg, respectively;
P
<0.05). Kidney renin and angiotensin type 1 receptor mRNA levels were not different. Additional studies showed that a delay in the initiation of HS until after birth was accompanied by later development of hypertension, although postnatal discontinuation of HS resulted in a gradual return of BP to normal values by 4 months of age. The results demonstrate that (1) kinins protect the developing animal from salt-sensitive hypertension, (2) lack of B
2
R from early development does not alter the maturation of BP under conditions of normal sodium intake, and (3) exposure to a HS diet during fetal life is not sufficient in itself to induce long-term hypertension in either wild-type or B
2
R null mice.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Cited by
66 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献