Carlstedt A, Fasth S, Hultén L, Nordgren S
Department of Surgery, University of Göteborg, Sahlgrenska sjukhuset, Sweden.
Acta Physiol Scand. 1988 Jul;133(3):423-31. doi: 10.1111/j.1748-1716.1988.tb08425.x.
The distribution of the sympathetic innervation to the internal anal sphincter (IAS) and rectum and the occurrence of different types of adrenergic receptors in the two organs were investigated in anaesthetized cats. Anal pressure and rectal motility were recorded by a manometric and a volumetric method respectively. Division of both the hypogastric nerves (HGN) and the lumbar colonic nerves (LCN) reduced the anal pressure by 46 +/- 6% of the resting pressure (40.9 +/- 6.4 mmHg) and consistently increased rectal motility. Efferent electrical stimulation of the HGN as well as the LCN elicited a contraction in the anus and the rectum, which, at maximal stimulation, caused the anal pressure to reach a similar level to that recorded before division of these nerves. After injection of phentolamine the anal contraction was abolished, whereas the rectal contraction was either abolished or converted to a beta-adrenergic relaxation. Propranolol caused increased rectal contraction in response to stimulation of the HGN and the LCN, whereas the anal contraction was unaffected. The results imply that the sympathetic nerves exert a tonic excitatory effect on the IAS and a dual effect on the rectum in the cat. The results also indicate that sympathetic fibres to the IAS are conveyed in both the HGN and the LCN. Inhibitory beta-adrenergic receptors seem to be of minor importance in regulating anal pressure.
在麻醉猫身上研究了交感神经对内括约肌（IAS）和直肠的支配分布以及这两个器官中不同类型肾上腺素能受体的存在情况。分别采用测压法和容积法记录肛门压力和直肠蠕动。切断腹下神经（HGN）和腰结肠神经（LCN）后，肛门压力降低至静息压力（40.9±6.4 mmHg）的46±6%，并持续增加直肠蠕动。对HGN以及LCN进行传出电刺激可引起肛门和直肠收缩，在最大刺激时，肛门压力达到与切断这些神经之前记录的水平相似。注射酚妥拉明后，肛门收缩消失，而直肠收缩要么消失，要么转变为β-肾上腺素能舒张。普萘洛尔使直肠对HGN和LCN刺激的收缩反应增强，而肛门收缩不受影响。结果表明，交感神经对猫的IAS具有紧张性兴奋作用，对直肠具有双重作用。结果还表明，支配IAS的交感纤维通过HGN和LCN传导。抑制性β-肾上腺素能受体在调节肛门压力方面似乎不太重要。
