Yu J H, Schneyer C A
Arch Oral Biol. 1984;29(2):141-6. doi: 10.1016/0003-9969(84)90118-3.
The separate roles of alpha- and beta-adrenergic receptors in regulating fluid and calcium (Ca) secretion by rat salivary glands were examined using phenylephrine (PE), an adrenergic agonist that acts predominantly on alpha-receptors, isoproterenol (ISO), an adrenergic agonist that acts predominantly on beta-receptors, and PE and ISO in combination with beta-adrenergic antagonist propranolol (PROP) and alpha-adrenergic antagonist phentolamine (PHENTO), respectively. PE evoked a greater volume of saliva from submandibular (SM) gland than from parotid (PA) gland, whereas ISO evoked a similar volume of saliva from both glands during 60-min of drug stimulation. PE even at a low dose had beta-adrenergic effects on flow rate of salivary glands because pretreatment of rats with PROP (1 mg/kg) 20 min before PE (5 mg/kg, i.p.) stimulation resulted in a 4-fold reduction in total volume of PE-evoked PA saliva. Thus alpha-adrenergic receptors play a major role in fluid secretion by SM glands but play only a minor role in PA glands. ISO evoked SM and PA saliva with Ca concentration higher than that evoked by PE. ISO (25 mg/kg, i.p.) also had an effect on alpha-adrenergic receptors as well as beta-adrenergic receptors. Although PHENTO did not significantly alter flow rate and volume of ISO-evoked PA or SM saliva, Ca concentration of ISO-evoked saliva was greatly potentiated by PHENTO. Total Ca output of ISO-evoked saliva from either gland was not significantly altered by PHENTO. Thus, in both salivary glands, activation of beta-adrenergic receptors evoked saliva with a high concentration of Ca.(ABSTRACT TRUNCATED AT 250 WORDS)
利用去氧肾上腺素(PE)、主要作用于α受体的肾上腺素能激动剂,异丙肾上腺素(ISO)、主要作用于β受体的肾上腺素能激动剂,以及分别与β肾上腺素能拮抗剂普萘洛尔(PROP)和α肾上腺素能拮抗剂酚妥拉明(PHENTO)联合使用的PE和ISO,研究了α和β肾上腺素能受体在调节大鼠唾液腺液体和钙(Ca)分泌中的不同作用。PE诱发的颌下腺(SM)唾液量比腮腺(PA)多,而在60分钟的药物刺激期间,ISO诱发的两个腺体的唾液量相似。即使是低剂量的PE对唾液腺流速也有β肾上腺素能效应,因为在PE(5mg/kg,腹腔注射)刺激前20分钟用PROP(1mg/kg)预处理大鼠,导致PE诱发的PA唾液总量减少了4倍。因此,α肾上腺素能受体在SM腺的液体分泌中起主要作用,但在PA腺中仅起次要作用。ISO诱发的SM和PA唾液中的钙浓度高于PE诱发的。ISO(25mg/kg,腹腔注射)对α和β肾上腺素能受体均有作用。虽然PHENTO没有显著改变ISO诱发的PA或SM唾液的流速和体积,但PHENTO极大地增强了ISO诱发唾液的钙浓度。PHENTO对任一腺体ISO诱发唾液的总钙输出量没有显著影响。因此,在两个唾液腺中,β肾上腺素能受体的激活均诱发了高钙浓度的唾液。(摘要截短于250字)