[The pattern-dependent mechanisms of the neural regulation of the microvascular tonus in the rat stomach].
The effects of electrical stimulation of the left splanchnic nerve in 1 s bursts at 4 s intervals at 5-80 Hz or continuously at 1-16 Hz (6 V, 1 ms) on gastric submucosal microvasculature were studied by the reflected light in vivo TV-microscopy. Burst stimulation, like a continuous one, induced frequency-dependent vasoconstrictor responses. Maximal reduction in diameter of both arterioles (by about 90%) and venules (by about 60%) occurred at the same total number of stimuli delivered for 1-min period of nerve stimulation continuously at 16 Hz or in bursts at 80 Hz. In other frequencies used, burst stimulation evoked significantly more pronounced contractile responses of arterioles (but not the venules), which followed by much less pronounced autoregulatory escape and poststimulatory hyperemia as compared to continuous stimulation at the comparable total number of impulses. After alpha-adrenoreceptor blockade, reduced in magnitude and slow developing contractile responses of arterioles persisted to stimulation in bursts rather than continuously suggesting the involvement of nonadrenergic co-transmitters) release. The data obtained show that not only the number of neural pulses but also their bursting pattern may have an informational role in microvascular contractile responses. Bursting pattern of nerve stimulation seems to be more "physiological" than the continuous one.
Polenov
S A
SA
Lentsman
M V
MV
D000818:Animals; D001160:Arterioles / Q000294:innervation / Q000502:physiology; D004558:Electric Stimulation; D005753:Gastric Mucosa / Q000098:blood supply* / Q000294:innervation* / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D008853:Microscopy / Q000295:instrumentation; D051381:Rats; D017208:Rats, Wistar; D013153:Splanchnic Nerves / Q000502:physiology; D013690:Television / Q000295:instrumentation; D014655:Vascular Resistance / Q000502:physiology*; D014661:Vasoconstriction / Q000502:physiology; D014666:Vasomotor System / Q000502:physiology*; D014699:Venules / Q000294:innervation / Q000502:physiology