Chronic Partial Ureteral Obstruction in the Neonatal Guinea Pig. I. Influence of Uninephrectomy on Growth and Hemodynamics
Chronic Partial Ureteral Obstruction in the Neonatal Guinea Pig. I. Influence of Uninephrectomy on Growth and Hemodynamics
复制标题
新生豚鼠慢性部分输尿管梗阻。
作者：
R. Chevalier;D. Kaiser
摘要：虽然梗阻性肾病是婴儿期肾功能不全的常见原因，但对影响慢性部分输尿管梗阻（CPUO）适应的因素了解甚少。豚鼠在出生后的前2天内接受单侧CPUO（组I），并在23 ± 3天龄时进行微球研究。为了研究功能性肾肿块对生长和血流动力学的作用，在输尿管狭窄时在组II中进行对侧肾切除。与假手术对照组（输尿管直径= 1 mm）相比，CPUO在两组中均导致躯体生长受损。第二组氮质血症动物的输尿管肾积水是可变的并且最严重（输尿管直径> 3 mm），这表明代偿性肾脏肥大减少和最差的躯体生长。肾血流量（RBF）在组II高于组I，并没有下降显着与组II中的CPUO的严重程度，其中灌注的肾小球数量与对照组相似。相比之下，肾血管阻力（RVR）增加了172%，在组I的动物与严重的CPUO，并与34%的灌注肾小球比在肥大的对侧肾。随着CPUO严重程度的增加，RBF倾向于分布到外部皮质区域在阻塞的肾脏I组，而RBF分布的转移是从外部到内部皮质在其余的肾脏II组。两组的滤过分数均因CPUO而下降，因此肾小球滤过率的降低在很大程度上是由于RBF以外的因素。总之，新生豚鼠的CPUO引起肾小球灌注的显著改变。侧肾切除可防止CPUO引起的RVR升高，这可能是通过保留所有肾单位的灌注并将血流转移到更成熟的更深皮质肾小球。
ABSTRACT: Although obstructive nephropathy is a frequent cause of renal insufficiency in infancy, factors influencing adaptation to chronic partial ureteral obstruction (CPUO) are poorly understood. Guinea pigs were subjected to unilateral CPUO within the first 2 days of life (Group I) and microsphere studies were performed at 23 ± 3 days of age. To also investigate the role of functional renal mass on growth and hemodynamics, contralateral nephrectomy was performed in Group II at the time of ureteral constriction. Compared to sham-operated controls (ureteral diameter = 1 mm) CPUO caused impaired somatic growth in both groups. Resulting hydroureteronephrosis was variable and most severe (ureteral diameter > 3 mm) in azotemic animals of Group II, which demonstrated reduced compensatory renal hypertrophy and poorest somatic growth.Mean arterial blood pressure was not affected by CPUO or uninephrectomy. Renal blood flow (RBF) was higher in Group II than Group I, and did not fall significantly with severity of CPUO in Group II, in which number of perfused glomeruli was similar to controls. In contrast, renal vascular resistance (RVR) increased by 172% in animals of Group I with severe CPUO, and was associated with 34% fewer perfused glomeruli than in the hypertrophied contralateral kidney. With increasing severity of CPUO, RBF tended to be distributed to outer cortical regions in the obstructed kidney of Group I, while the shift in RBF distribution was from outer to inner cortex in the remaining kidney of Group II. Filtration fraction fell as a result of CPUO in both groups, such that reduction in the glomerular filtration rate was due in large part to factors other than RBF. In conclusion, CPUO in the neonatal guinea pig causes marked alterations of glomerular perfusion. Contralateral nephrectomy prevents the rise in RVR due to CPUO, possibly by preserving perfusion to all nephrons and shifting blood flow to more mature deeper cortical glomeruli.