Effect of EGTA on Protein Release and Cyclic AMP Accumulation in Rat Parotid Gland

1973 ◽  
Vol 51 (12) ◽  
pp. 997-1001 ◽  
Author(s):  
B. Harfield ◽  
A. Tenenhouse
Keyword(s):  
Cyclic Amp ◽  
Parotid Gland ◽  
Protein Release ◽  
Camp Accumulation ◽  
Secretion Process ◽  
Cyclic Amp Accumulation ◽  
Rat Parotid Gland ◽  
Rat Parotid

An attempt was made to determine whether accumulation of cyclic AMP (cAMP) was essential for epinepnrine-stimuiated secretion of protein from the rat parotid gland in vitro. EGTA (10−2 M) did not inhibit secretion but did reduce cAMP accumulation by 80% suggesting that this nucleotide may not be an essential intermediate in the epinephrine-stimuiated secretion process.

Kinetic analysis of rat parotid gland muscarinic receptors in vivo: comparison with brain and heart

1993 ◽  
Vol 264 (3) ◽  
pp. G541-G552
Author(s):  
Y. Hiramatsu ◽  
R. Kawai ◽  
R. C. Reba ◽  
T. R. Simon ◽  
B. J. Baum ◽  
...  
Keyword(s):  
Parotid Gland ◽  
Plasma Membranes ◽  
Specific Binding ◽  
Muscarinic Acetylcholine Receptor ◽  
Binding Potential ◽  
Specific Binding Sites ◽  
Rat Parotid Gland ◽  
Rat Parotid

(RR)- and (SS)-quinuclidinyl iodobenzilate enantiomers [(RR)- and (SS)-IQNB, active and inert, respectively] have been synthesized for quantitative evaluation of muscarinic acetylcholine receptor (mAChR) binding. Pharmacokinetic approaches have not been used previously to assess in vivo IQNB binding in nonexcitable tissues. We have applied this method to examine mAChRs in rat parotid gland in comparison to those in brain and heart. Short-term infusion studies in vivo showed that the "instantaneous" reversible binding of (RR)- and (SS)-IQNB was high in the parotid (greater nonspecific binding potential), intermediate in the heart, and lowest in cortex and cerebellum. Long-term bolus injection experiments showed that the parotid gland mAChRs possessed a binding potential for receptor specific sites (380), which was intermediate between that of parietal cortex (930) and cerebellum (10) and greater than that of heart (165). In vitro binding to plasma membranes was generally consistent with the in vivo findings. In aggregate, these studies show that mAChRs can be evaluated in vivo in a nonexcitable tissue with the use of stereospecific ligands and a pharmacokinetic approach. The data suggest that IQNB, a mAChR antagonist, can identify characteristics of specific binding sites, which may reflect tissue differences.

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