( sup 3 H)protein secretion in rat parotid gland: Substance P-. beta. -adrenergic synergism

Journal Article · Tue Dec 01 00:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:7027227

Dreux, C; Imhoff, V; Rossignol, B ^[1]

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1. Universite Paris-Sud (France)

In parotid fragment ({sup 3}H)protein, secretion induced by substance P was moderate, but strongly Ca dependent. However, secretion induced by isoproterenol was large and Ca independent. Potentiation of protein secretion was observed when substance P (SP) and isoproterenol (ISO) acted together. Addition of 10{sup {minus}8} M SP caused a shift to the left in the secretion dose-response curve caused by ISO, but did not enhance ISO-induced maximal response. The potentiating effect seems to be a postreceptor event, since it can be mimicked by forskolin (FK), known to induce directly cAMP accumulation, thus bypassing the {beta}-adrenergic receptor. The synergism described above was, therefore, investigated at the second messenger production level. Stimulation of parotid gland fragments by simultaneous addition of SP plus ISO or FK did not modify cAMP nor inositol trisphosphate (IP{sub 3}) accumulation induced independently by each secretagogue alone. The ionophore A23187 was also able to potentiate secretion induced by a {beta}-adrenergic agonist, this effect being totally abolished by external calcium omission, thus suggesting a role for external calcium in this potentiation phenomenon. These results suggest that the potentiation phenomenon observed is a postreceptor event that occurs at a step distal from the second messenger production.

• OSTI ID: 7027227
• Journal Information: American Journal of Physiology; (USA), Vol. 253:6; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
LABELLED COMPOUNDS
SECRETION
PROTEINS
BIOCHEMISTRY
RECEPTORS
CHEMICAL ACTIVATION
AMP
CALCIUM 45
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
DOSE-RESPONSE RELATIONSHIPS
INOSITOL
LEUCINE
SALIVARY GLANDS
SYMPATHOMIMETICS
SYNERGISM
TRITIUM COMPOUNDS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
AMINO ACIDS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCIUM HALIDES
CALCIUM ISOTOPES
CARBOHYDRATES
CARBOXYLIC ACIDS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
DRUGS
EVEN-ODD NUCLEI
GLANDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INOSITOLS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MEMBRANE PROTEINS
MONOSACCHARIDES
NUCLEI
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
SACCHARIDES
550201* - Biochemistry- Tracer Techniques