Is VIP the putative non-cholinergic, non-adrenergic neurotransmitter controlling protein secretion in rat lacrimal glands?
In the combined presence of cholinergic and adrenergic antagonists, electrical field stimulation (FS) caused a marked reversible increase in protein output from superfused rat lacrimal gland segments. The FS-evoked protein output was abolished by the nerve blocking drug tetrodotoxin (TTX; 10(-6) M) whereas high potassium (K+; 100 mM) continued to elicit secretion. Vasoactive intestinal polypeptide (VIP), but not adenosine 5'-triphosphate (ATP), stimulated protein secretion in a manner almost identical to that observed in response to FS. The results suggest that the non-cholinergic, non-adrenergic secretory response may involve VIP as an endogenous neurotransmitter.
Hussain
M
M
School of Applied Biology, Lancashire Polytechnic, Preston.
Singh
J
J
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007765:Lacrimal Apparatus / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D013779:Tetrodotoxin / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D011506:Proteins; D014660:Vasoactive Intestinal Peptide; D013779:Tetrodotoxin; D000255:Adenosine Triphosphate; D011188:Potassium