Parasympathetic denervation increases responses to VIP in isolated rat parotid acini

Journal Article · Sat Jul 01 00:00:00 EDT 1989 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(89)90103-4· OSTI ID:5037793

McMillian, M K; Talamo, B R ^[1]

---

1. Tufts Univ. School of Medicine, Boston, MA (USA)

Vasoactive intestinal peptide (VIP) is a putative neurotransmitter found in the salivary glands of many species, including the rat parotid gland. Parasympathetic denervation has been reported to deplete VIP in the rat parotid gland and to lead to supersensitivity to this peptide in vivo. We have compared the effects of VIP on acini isolated from parasympathetically denervated and unoperated parotid glands to examine possible supersensitivity to the peptide in vitro. VIP normally produced responses similar to those obtained with a low concentration of the beta adrenergic agonist isoproterenol (ISO), but strikingly different from the effects obtained with the muscarinic agonist carbachol (CARB). In parotid membrane preparations, VIP stimulated adenylate cyclase activity. Dissociated acini treated with VIP showed increases in cAMP accumulation and amylase release which were potentiated by forskolin and also by inhibition of phosphodiesterase. After parasympathetic denervation, maximal effects of VIP on adenylate cyclase, cAMP accumulation and amylase release in intact cells were increased two- to five-fold over contralateral control (or unoperated) parotid responses. The increase in adenylate cyclase-mediated responses after denervation was specific to VIP; there was no increased response nor increased sensitivity of any of these responses to ISO. Specific (125I)VIP binding to parotid acini increased two-fold per gland and three-fold per mg of protein after denervation; this probably explains the observed increases in the response to VIP.

• OSTI ID: 5037793
• Journal Information: Peptides (Fayetteville, New York); (USA), Vol. 10:4; ISSN 0196-9781
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PEPTIDES
BIOCHEMICAL REACTION KINETICS
AMP
AMYLASE
CYCLASES
ENZYME ACTIVITY
IN VITRO
IODINE 125
NERVES
RATS
SALIVARY GLANDS
SYMPATHOLYTICS
SYMPATHOMIMETICS
TRACER TECHNIQUES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BODY
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
GLANDS
GLYCOSYL HYDROLASES
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LYASES
MAMMALS
NERVOUS SYSTEM
NUCLEI
NUCLEOTIDES
O-GLYCOSYL HYDROLASES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques