These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Effect of sodium nitroprusside and 8-bromo cyclic GMP on nerve-mediated and acetylcholine-evoked secretory responses in the rat pancreas.
    Author: Yago MD, Tapia JA, Salido GM, Adeghate E, Juma LM, Martinez-Victoria E, Mañas M, Singh J.
    Journal: Br J Pharmacol; 2002 May; 136(1):49-56. PubMed ID: 11976267.
    Abstract:
    The effects of sodium nitroprusside (SNP) and 8-bromo-guanosine 3'5' cyclic monophosphate (8-Br-cyclic GMP) on nerve-mediated and acetylcholine (ACh)-evoked amylase secretion, tritiated choline ([3H]-choline) release and on intracellular free calcium concentration ([Ca2+]i) in the isolated rat pancreas were investigated. Electrical field stimulation (EFS; 10 Hz) and ACh (1 x 10(-5) M) caused large increases in amylase output from pancreatic segments. The response to ACh was blocked by atropine (1 x 10(-5) M) whereas the EFS-evoked response was markedly reduced but not abolished. In contrast, pretreatment with tetrodotoxin (1 x 10(-6) M) abolished the secretory effect of EFS. Either SNP (1 x 10(-3) M) or 8-Br-cyclic GMP (1 x 10(-4) M) inhibited amylase secretion compared to basal. Combining either SNP or 8-Br-cyclic GMP with EFS resulted in a marked decrease in amylase output compared to EFS alone. In contrast, either SNP or 8-Br-cyclic GMP had no significant effect on the amylase response to ACh. When extracellular Ca2+ concentration ([Ca2+]o) was elevated from 2.56 mM to 5.12 mM, SNP failed to inhibit the response to EFS. EFS stimulated the release of 3H from pancreatic segments preloaded with [3H]-choline. Either SNP or 8-Br-cyclic GMP had no effect on basal 3H release but significantly reduced the EFS-evoked response. In fura-2 loaded acinar cells, SNP elicited a small decrease in [Ca2+]i compared to basal and had no effect on the ACh-induced [Ca2+]i peak response. Nitric oxide may modulate the release of endogenous neural ACh in response to EFS in the rat pancreas.
    [Abstract] [Full Text] [Related] [New Search]