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Autonomic responsiveness in stress‐sensitive and stress‐resistant pigs
Author(s) -
GREGORY N. G.,
LISTER D.
Publication year - 1981
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1111/j.1365-2885.1981.tb00712.x
Subject(s) - phenylephrine , heart rate , blood pressure , tyramine , sympathetic nervous system , autonomic nervous system , medicine , endocrinology , baroreflex , norepinephrine , anesthesia , dopamine
The responsiveness of the autonomic nervous system was studied in twenty‐six 140 day old thiopentone anaesthetized lean stress‐sensitive Pietrain (P) and fatter stress‐resistant Gloucester (G) pigs, using the Valsalva like manoeuvre (VLM), and the i.v. tyramine, noradrenaline (NA) and phenylephrine tests. The heart rate responses to the VLM and tyramine tests were greater in P. The pressor response to NA was lower in P, and the change in heart rate per unit change in blood pressure‐during phenylephrine infusion was the same in the two breeds. The sympathetic nervous system in P was, therefore, more responsive than that in G, and this was attributable to a higher pre‐adrenoreceptor responsiveness in P. The potentially greater sympathetic responsiveness in stress‐sensitive pigs could account for their greater leanness, their stress‐induced metabolic acidosis, and for their susceptibility to myocardial failure.