Species differences in the reflex effects of lingual afferent nerve stimulation on lip blood flow and arterial pressure

Abstract

We evoked changes in lower lip blood flow and systemic arterial blood pressure by electrically stimulating the central cut end of the lingual nerve in artificially ventilated, urethane-anesthetized, cervically vago-sympathectomized cats, rats, rabbits, and guinea pig. The systemic arterial blood pressure changes were species-dependent: increases in rat, consistent decreases in rabbit and guinea pig, and variable among individuals in cat. In cat and rabbit, lip blood flow increases, which occurred only ipsilaterally to the stimulated nerve and showed no statistically significant correlation with the systemic arterial blood pressure changes. In rat, the ipsilateral lip blood flow increase was markedly greater than the contralateral one, and although there was a significant correlation between each of them and the systemic arterial blood pressure changes, the ipsilateral increase presumably included an active vasodilatation. In guinea pig, lip blood flow decreased on both sides in proportion to the systemic arterial blood pressure reductions. Thus, species variability exists in the sympathetic-mediated systemic arterial blood pressure changes and parasympathetic-mediated lip blood flow responses themselves, and in the relationship between them.

Autonomic and cardiovascular effects of pentobarbital anesthesia during trigeminal stimulation in cats

“…1,2,8,35 In the present study, we demonstrated that SBP-LF was reduced during TDR and that TDR was blunted by phentolamine and hexamethonium. To our knowledge, this is the first report to describe the autonomic effects of TDR using spectral analysis of BP and HR variability.…”

“…8,10 The hemodynamic response to nociceptive stimulation may be influenced by the potentially different plane of anesthesia that animals experience at the various sampling times. 27 We evaluated the cardiovascular and autonomic responses to LN stimulation at specific plasma pentobarbital concentrations.…”

“…8 The BP response to trigeminal stimulation was shown to be an increase in rats, and consistent decrease in rabbits and guinea pigs, both anesthetized with urethane. However, in pentobarbital or urethane/α-chloralose-anesthetized cats, electric stimulation of trigeminal nerve caused both pressor and depressor alteration in BP.…”

Activation of the carotid chemoreflex secondary to muscle metaboreflex stimulation in men

“…Aggarwal et al (1) suggest that even though the interactions were not consistently seen in animals, they may still be present in humans. Indeed, species differences in autonomic cardiovascular control are known to exist (20,21).Previous human studies have investigated interactions between the metaboreflex and the chemoreflex during exercise (13,15,17). These studies found that metaboreceptors, chemoreceptors, and baroreceptors all play a role in the sympathetic response to hypoxic exercise.…”

“…Aggarwal et al (1) suggest that even though the interactions were not consistently seen in animals, they may still be present in humans. Indeed, species differences in autonomic cardiovascular control are known to exist (20,21).…”