Physiological and biochemical indices of neurohypophyseal function in the aging Fischer rat.
Physiological and biochemical indices of neurohypophyseal function in the aging Fischer rat.
复制标题
老龄费舍尔大鼠神经垂体功能的生理生化指标。
DOI：
10.1159/000125571
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发表时间：
1990
影响因子：
4.1
通讯作者：
Sladek,CD
中科院分区：
文献类型：
--
作者：
Silverman,WF;Aravich,PA;SladekJr,JR;Sladek,CD
为了解决文献中关于老化对大鼠下丘脑神经垂体系统（HNS）影响的相互矛盾的报告，在基础和刺激条件下，对年轻（4个月）、完全成熟（14个月）和老年（25个月）Fischer 344大鼠中与HNS相关的多个参数进行了评价。用放射免疫法测定血清、尿、脑和垂体中催产素和加压素的含量。还从相同受试者中获得了体重、饮水量、尿量、血清红细胞压积和血浆渗透压摩尔浓度的信息，并与这些数据一起进行分析。最后，半定量组织荧光评估的去甲肾上腺素能神经支配的mediobasal下丘脑从相同的动物进行，以确定中枢传入输入的HNS随着年龄的增长的程度。在基础条件下，三个年龄组的血管加压素和催产素的循环水平没有显着差异。血清加压素浓度增加后，水剥夺，增加是在所有年龄组的可比性。血清催产素也增加了水剥夺后，在所有组中，但增加更大的25个月大的大鼠相对于4个月大的大鼠。加压素的尿排泄量被用作每日加压素分泌的指标。老年大鼠的尿中加压素浓度低于年轻对照组，尽管成年和老年动物的尿量增加意味着尿液中的总加压素排泄量在研究的所有年龄段均相当。成熟和老年大鼠的尿量增加似乎并不反映肾脏对加压素的敏感性降低，因为在循环加压素浓度相当的情况下，所有年龄组在禁水期间的尿量减少相当。这些数据表明，在14月龄和25月龄大鼠中观察到的尿量增加可能是液体摄入量增加的函数，而不是HNS中的活动过度。老年大鼠垂体后叶中两种肽的浓度均降低，但腺体中肽的总量没有变化。只有催产素在下丘脑中显示出与年龄相关的变化，在年龄最大的受试者中减少。这些数据表明，在25月龄的Fisher 344大鼠中，响应脱水而分泌足够量的加压素的能力不受影响。
In order to resolve conflicting reports in the literature on the effect of aging on the hypothalamo neurohypophyseal system (HNS) in rats, multiple parameters associated with the HNS were evaluated in young (4 months), fully mature (14 months), and old (25 months) Fischer 344 rats under basal and stimulated conditions. The hypothalamic hormones oxytocin and vasopressin were compared in radioimmunoassay of serum, urine, brain and pituitary. Information on body weight, water intake, urine output, serum hematocrit and plasma osmolality was also obtained from the same subjects and analyzed together with these data. Finally, semi quantitative histofluorescence assessment of the noradrenergic innervation of the mediobasal hypothalamus from the same animals was performed to determine the extent of central afferent input to the HNS with advancing age. The circulating levels of vasopressin and oxytocin did not significantly differ in the three age groups under basal conditions. Serum vasopressin concentration was increased following water deprivation, and the increase was comparable in all age groups. Serum oxytocin was also increased following water deprivation in all groups, but the increase was greater in the 25-month-old rats relative to the 4-month-old rats. Urinary excretion of vasopressin was used as an index of daily vasopressin secretion. The urinary concentration of vasopressin was less in aged rats relative to young controls, though an increased urine volume in the mature and old animals meant that total vasopressin excretion in the urine was comparable at all ages studied. The increased urine volume in the mature and aged rats does not appear to reflect a decrease in renal sensitivity to vasopressin, since all age groups demonstrated a comparable reduction in urine volume during water deprivation, at comparable concentrations of circulating vasopressin. These data suggest that the increase in urine volume observed in the 14- and 25-month-old rats may be a function of increased fluid intake rather than hyperactivity in the HNS. The concentrations of both peptides were reduced in the posterior pituitary of aged rats, though again, the total amount of peptide in the gland did not change. Only oxytocin showed an age-related change in the hypothalamus, decreasing in the oldest subjects. These data indicate that the ability to secrete adequate quantities of vasopressin in response to dehydration is not compromised in Fisher 344 rats up to 25 months of age.