Polenov S A, Cherniavskaia G V
Fiziol Zh SSSR Im I M Sechenova. 1982 Mar;68(3):391-8.
In acute experiments on cats, the mean coefficient of capillary filtration (CFC) in denervated small intestine was 0.10 ml/min/mm Hg/100 g and the stretching ability of the intestinal venous vessels was 0.21 ml/mm Hg/100 g. Infusion of noradrenaline (5 micrograms/min) reduced the CFC by 33% and the stretching ability by 24%. Blockade of vascular alpha-adrenoreceptors abolished and beta-adrenoreceptors augmented the noradrenaline effect on CFC and stretching ability. The data obtained indicate presence of both alpha- and beta-adrenoreceptors in precapillary sphincters and venous vessels of small intestine. Stimulation of the alpha-adrenoreceptors entails constriction of precapillary sphincters and decreases venous stretching ability whereas stimulation of beta-adrenoreceptors leads to opposite effects. Noradrenaline exerts main effect on alpha-adrenoreceptors of precapillary sphincters and venous vessels in the denervate intestine; alpha-blockade is followed by an obvious beta-effect in the form of relaxation of precapillary sphincters and increase of the venous stretching ability.
在对猫进行的急性实验中，去神经支配的小肠毛细血管滤过系数（CFC）平均值为0.10毫升/分钟/毫米汞柱/100克，肠静脉血管的舒张能力为0.21毫升/毫米汞柱/100克。输注去甲肾上腺素（5微克/分钟）可使CFC降低33%，舒张能力降低24%。血管α-肾上腺素能受体阻断可消除这种作用，而β-肾上腺素能受体阻断则增强去甲肾上腺素对CFC和舒张能力的影响。所获得的数据表明，小肠毛细血管前括约肌和静脉血管中同时存在α-和β-肾上腺素能受体。刺激α-肾上腺素能受体会导致毛细血管前括约肌收缩，并降低静脉舒张能力，而刺激β-肾上腺素能受体则会产生相反的效果。去甲肾上腺素对去神经支配肠段的毛细血管前括约肌和静脉血管的α-肾上腺素能受体起主要作用；α-受体阻断后会出现明显的β-效应，表现为毛细血管前括约肌舒张和静脉舒张能力增强。
