Holmberg J, Lundvall J
Acta Physiol Scand. 1976 Dec;98(4):400-6. doi: 10.1111/j.1748-1716.1976.tb10328.x.
In a previous investigation, parasympathetic activation of the submandibular gland in the cat was found to cause a considerable increase of regional tissue osmolality, the degree of which was related to the evoked functional hyperemia; intra-arterial hypertonic infusion to the resting gland producing tissue hyperosmolality of similar magnitudes caused graded and marked dilatations (Lundvall and Holmberg 1974). It was concluded that hyperosmolality contributes significantly to the functional hyperemia response. In the present study evidence is presented to indicate that tissue hyperosmolality is a mediator of the dilatation associated with sympathetic activation as well. An increase of tissue hyperosmolality, as traced in the venous effluent, was found at all frequencies of sympathetic stimulation (2-16 Hz). At high stimulation rates it sometimes exceeded the resting control level by more than 20 mOsm/kg H2O. There was a direct relation between the degree of venous hyperosmolality and the hyperemia response observed immediately after cessation of stimulation. Comparison of the dilator effects evoked by sympathetic stimulation and by hypertonic infusion to the resting gland indicated that tissue hyperosmolality is an important causal factor for the nerve induced dilatation, especially at low and moderate stimulation rates.
在先前的一项研究中，发现猫下颌下腺的副交感神经激活会导致局部组织渗透压显著升高，其升高程度与诱发的功能性充血有关；对静息状态的腺体进行动脉内高渗灌注，产生相似程度的组织高渗，会引起分级且明显的扩张（伦德瓦尔和霍尔姆贝里，1974年）。得出的结论是，高渗对功能性充血反应有显著贡献。在本研究中，有证据表明组织高渗也是与交感神经激活相关的扩张的介质。在交感神经刺激的所有频率（2 - 16赫兹）下，都发现静脉流出液中的组织高渗有所增加。在高刺激频率下，其有时会比静息对照水平高出超过20毫渗摩尔/千克水。静脉高渗程度与刺激停止后立即观察到的充血反应之间存在直接关系。交感神经刺激和对静息腺体进行高渗灌注所诱发的扩张效应比较表明，组织高渗是神经诱发扩张的一个重要因果因素，尤其是在低和中等刺激频率下。
