Effects of capsaicin applied perineurally to the vagus nerve on cardiovascular and respiratory functions in the cat.

Abstract

SUMMARY1. The effects of capsaicin applied perineurally to the cervical vagus nerves have been studied on cardiovascular and respiratory functions in urethane anaesthetized cats.2. Application of capsaicin resulted in a moderate but significant decrease in the mean arterial blood pressure and in changes of the heart rate whose direction and magnitude depended on the initial cardiac frequency.3. Subsequent to these alterations, which may be attributed to a direct stimulation by capsaicin ofvagal afferents, a transient block ofimpulse propagation was observed.4. Three to five days after pre-treatment of the cervical vagus nerves with capsaicin, phenyldiguanidine and veratrine given intravenously invariably evoked bradycardia, hypotension and apnoea, while the reflex responses to intravenous injection of capsaicin and some of its pungent congeners were greatly reduced or even abolished.5. It is suggested that vagal afferent fibres mediating cardiovascular and respiratory chemo-reflexes are separated into chemo-specifically different populations. Perineural application of capsaicin may be a useful tool for elucidating the role of different populations of peptide-containing vagal afferent fibres in the regulation of cardiovascular and respiratory functions.

Role of vagal afferent C fibres in the bradycardiac response to an increase in arterial blood pressure in ferrets

“…The degree of C fibre blockade was estimated simultaneously using intravenous injection of phenyl biguanide (PBG) to elicit the C fibre-mediated cardiopulmonary Bezold-Jarisch reflex i.e. the triad of hypotension, bradycardia and apnoea (Jancs6 & Such, 1983).…”

Skin blood flow disturbances in the contralateral limb in a peripheral mononeuropathy in the rat

“…8,10,19,27 In several electrophysiological studies, it has been shown that the neurotoxic effects of capsaicin on impulse propagation are specific to primary afferent nerve fibers. 2,17,20,35,43 It has also been demonstrated that capsaicin does not exert effects on non-sensory (i.e autonomic and motor) nerve fibers. 7,11,19 The cotton containing the capsaicin solution was removed after 15 min, after which excess capsaicin solution was absorbed with a dry piece of cotton.…”

Puberte döneminde capsaicin uygulanan sıçanların karaciğerinde COX-1 ve COX-2' nin immunohistokimyasal lokalizasyonu

“…CAP organizmada başta kardiovasküler, gastrointestinal ve solunum sistemleri olmak üzere pek çok sistemin histo-fizyolojileri üzerine etki göstermektedir (8,29). Yapılan çalışmalarda capsaicinin yağ dokuda lipid mobilizasyonunu uyardığı ve serum trigliserid seviyesini düşürdüğünü ifade edilmiştir (9).…”