VIP(6-28)(human, rat, porcine, bovine) 是一种有效的外源性血管活性肠肽 (VIP) 拮抗剂。
VIP(6-28)(human, rat, porcine, bovine) is an effective antagonist of the actions of exogenous vasoactive intestinal peptide (VIP) on cAMP. VIP[1]
VIP(6-28) is an effective VIP antagonist in the superior cervical ganglion (SCG) , and results obtained using this analog indicate that endogenous VIP can participate in a positive feedback loop in injured sympathetic neurons in which it enhances its own expression. VIP(6-28), when added to short-term cultures of adult SCG at a concentration of 10, 30, or 100 μM, reduces the increase in cAMP levels produced by stimulation with 10 μM VIP by 52, 64, or 81%, respectively. At any of these concentrations tested, VIP(6-28) by itself does not alter cAMP levels. In contrast to its ability to reduce the VIP-stimulated elevation in cAMP levels by 64%, the addition of 30 μM VIP(6-28) to culture medium does not significantly alter cAMP levels measured after stimulation of adult ganglia with either isoproterenol or forskolin (10 μM each). Similar results on the ability of VIP(6-28) to block VIP-stimulated increases in cAMP levels are obtained in neuron-enriched and in non-neuronal cell-enriched dissociated cultures[1].
[1]. Mohney RP, et al. Vasoactive intestinal peptide enhances its own expression in sympathetic neurons after injury. J Neurosci. 1998 Jul 15;18(14):5285-93.
Kinase experiment: | Adult rats are killed by decapitation. The SCGs are removed, desheathed, placed in organ culture, and maintained for 24 or 48 hr in F-12 defined medium equilibrated with 95% O2 and 5% CO2. Some ganglia are preincubated for 30 min in medium containing the VIP receptor antagonist VIP(6-28), and then transferred for 24 hr to medium containing both VIP(6-28) and an agonist. In experiments in which cAMP is to be measured, ganglia are removed from animals and preincubated for 30 min in F-12 medium containing 500 μM IBMX to prevent the metabolism of cAMP. Ganglia are then incubated for an additional 30 min in F-12 medium with IBMX and the compound to be studied. When the action of VIP(6-28) is examined, it is added to the medium during the last 5 min of the preincubation and throughout the incubation. Ascorbic acid (0.2 mg/mL) is added to cultures containing isoproterenol to retard oxidation of the catecholamine. No significant differences in peptide levels are detected between ganglia maintained in F-12 alone and those cultured in medium containing ascorbic acid[1]. |
参考文献: [1]. Mohney RP, et al. Vasoactive intestinal peptide enhances its own expression in sympathetic neurons after injury. J Neurosci. 1998 Jul 15;18(14):5285-93. | |
动态评分
0.0