Pertussis toxin prevents the inhibitory effect of adenosine and unmasks adenosine-induced excitation of mammalian motor nerve endings.
Pertussis toxin (PTX), which blocks certain classes of guanine nucleotide binding proteins (G proteins), consistently blocked the inhibitory effects of adenosine (100 microM-250 microM) on quantal acetylcholine (ACh) secretion in rat phrenic nerve hemidiaphragm preparations. PTX pretreatment also highlighted long-lasting increases in evoked ACh release elicited by adenosine. The results suggest that specific G proteins are involved in mediating the inhibitory effects of adenosine at motor nerve endings.
Silinsky
E M
EM
Department of Pharmacology, Northwestern University Medical School, Chicago, Illinois 60611.
Solsona
C
C
Hirsh
J K
JK
D000109:Acetylcholine / Q000494:pharmacology; D000241:Adenosine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D008297:Male; D009046:Motor Neurons / Q000187:drug effects*; D009411:Nerve Endings / Q000187:drug effects*; D037342:Pertussis Toxin; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D000241:Adenosine; D000109:Acetylcholine