Vandeputte-Van Messom G, Burvenich C, Peeters G
Am J Vet Res. 1984 Oct;45(10):2145-9.
Under continuous IV infusion of oxytocin, milk leakage was elicited in 6 lactating cows with full udders by induction of a vacuum (-30 cm of water) around 1 mammary papilla (teat) with a plethysmographic apparatus. The volumes of milk loss were measured every minute. Epinephrine injected either into the jugular vein (20, 100, and 500 micrograms) or into the external pudic artery (1.5, 7.5, and 37.5 micrograms) induced an increase in milk leakage in 5 cows. This effect could be antagonized by the beta-blocking agent sotalol hydrochloride (0.5 to 4 mg) injected into the external pudic artery. In 1 cow, however, epinephrine given intra-arterially exerted a biphasic effect, small doses inducing stimulation, and large doses evoking inhibition of milk loss. The stimulating effects were blocked by sotalol (2 mg). The inhibiting effects were antagonized by the alpha-blocking agent prazosin (2 mg).
在持续静脉输注催产素的情况下，使用体积描记仪在6头乳房饱满的泌乳奶牛的1个乳头（乳突）周围施加负压（-30厘米水柱），引发了乳汁外溢。每分钟测量乳汁流失量。向颈静脉注射肾上腺素（20、100和500微克）或向阴部外动脉注射肾上腺素（1.5、7.5和37.5微克），可使5头奶牛的乳汁外溢增加。向阴部外动脉注射β受体阻滞剂盐酸索他洛尔（0.5至4毫克）可拮抗这种作用。然而，在1头奶牛中，动脉内注射肾上腺素产生了双相效应，小剂量引起刺激，大剂量则抑制乳汁流失。索他洛尔（2毫克）可阻断刺激作用。α受体阻滞剂哌唑嗪（2毫克）可拮抗抑制作用。
