ISSN:
1432-1912
Keywords:
Rabbit jejunal artery
;
Contraction
;
Cotransmission
;
ATP
;
Noradrenaline
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Isotonic contractions of the rabbit jejunal artery were evoked by perivascular nerve stimulation with trains of 10 or 100 stimuli at 2 Hz or 10 Hz. Short trains of stimuli elicited contractions that were totally resistant to α-adrenoceptor blockade (0.1 μmol/l prazosin) but blocked by α,β-methylene ATP (1 μmol/l). A substantial noradrenergic component of contraction comprising about 50% of the total could be evoked by adjusting the stimulation parameters (increasing the frequency and/or number of stimuli in a train). The noradrenergic and the purinergic components are derived from sympathetic nerves as both were blocked by TTX and the adrenergic neurone blocker guanethidine (3 μmol/l). It is concluded that the contraction of the rabbit jejunal artery to short trains of stimuli is predominantly purinergic, a nor-adrenergic component only being revealed at higher frequencies of stimulation or during longer trains of stimuli. The purinergic component of contraction is derived from sympathetic nerves and not from a separate population of purinergic nerves.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00176620
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