Malendowicz L K, Nussdorfer G G
Department of Histology and Embryology, School of Medicine, Poznan, Poland.
Neuropeptides. 1993 Aug;25(2):145-50. doi: 10.1016/0143-4179(93)90095-r.
VIP is widely distributed in the body, and among others is present within the hypothalamo-pituitary-adrenal axis. The aim of this study was to investigate the effect of prolonged VIP administration on the structure and function of the rat adrenal cortex. Adult female rats were treated for 7 or 14 days with VIP (1.5 micrograms/100 g/day). This treatment did not change adrenal weight and evoked only slight changes in the stereologic parameters of adrenal cortex (volume of adrenocortical zones, average cell volume and number of cells in the gland). On the contrary, basal plasma corticosterone levels were markedly lowered (44% and 26% of control values in 7- and 14-day experiments, respectively), an effect accompanied by a significant decrease in corticosterone output by adrenal slices. After standardized ether stress, blood corticosterone concentration was similar in control and 14-day VIP-treated rats, while corticosterone secretion by adrenal quarters was higher in VIP-administered animals. Thus, prolonged VIP administration results in an unusual inhibition of corticosterone secretion in the rat, which is not coupled with a compensatory hypertrophy of the rat adrenal cortex. Such changes may depend on a modulatory action of VIP on the hypothalamo-pituitary-adrenal axis, and its possible mechanism is discussed.
血管活性肠肽（VIP）在体内广泛分布，其中包括下丘脑 - 垂体 - 肾上腺轴。本研究的目的是探讨长期给予VIP对大鼠肾上腺皮质结构和功能的影响。成年雌性大鼠用VIP（1.5微克/100克/天）治疗7天或14天。这种治疗没有改变肾上腺重量，仅引起肾上腺皮质立体学参数的轻微变化（肾上腺皮质区体积、平均细胞体积和腺体中的细胞数量）。相反，基础血浆皮质酮水平显著降低（在7天和14天实验中分别为对照值的44%和26%），这种效应伴随着肾上腺切片皮质酮产量的显著降低。在标准化乙醚应激后，对照大鼠和接受14天VIP治疗的大鼠的血皮质酮浓度相似，而给予VIP的动物肾上腺四分之一切片的皮质酮分泌更高。因此，长期给予VIP导致大鼠皮质酮分泌出现异常抑制，这与大鼠肾上腺皮质的代偿性肥大无关。这种变化可能取决于VIP对下丘脑 - 垂体 - 肾上腺轴的调节作用，并对其可能的机制进行了讨论。
