Sympathectomy-induced increases in calcitonin gene-related peptide (CGRP)-, substance P- and vasoactive intestinal peptide (VIP)-levels in parotid and submandibular glands of the rat.
The neuropeptide contents of rat salivary glands were increased four weeks after sympathetic postganglionic denervation (but not after preganglionic denervation): calcitonin gene-related peptide (CGRP) by 400 and 65% in the parotid and submandibular glands, respectively; substance P by 30% in the submandibular gland; and vasoactive intestinal peptide (VIP) by 30% in the parotid gland. The sensory neurotoxin capsaicin prevented the expected increases of CGRP and substance P in the submandibular glands and of VIP in the parotid glands. The CGRP-increase in the parotid gland was, however, only reduced (by 65%). Parasympathetic otic ganglionectomy reduced the peptide levels in the parotid glands (CGRP--50%, VIP--98% and substance P--99%). From these residual levels, CGRP increased almost 8-fold and substance P 3-fold in response to the sympathetic denervation, while VIP was unaffected. In the parasympathetically denervated glands, the capsaicin-sensitive contribution to the CGRP-response to sympathetic denervation was roughly estimated to be more than 25% but less than 40%, while the corresponding contribution to the substance P-response was roughly estimated to be more than 6% but less than 58%. Most likely not only CGRP/substance P-containing sensory C-fibres (submandibular and parotid glands) but also parasympathetic VIP-containing secretomotor and vasomotor fibres (parotid glands) contributed to the capsaicin-sensitive response to sympathetic denervation.
Ekström
J
J
Department of Pharmacology, Institute of Physiology and Pharmacology, Sahlgrenska Academy at Göteborg University, Box 431, 40530 Göteborg, Sweden. jorgen.ekstrom@pharm.gu.se
Ekman
R
R
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis*; D002211:Capsaicin / Q000494:pharmacology; D005260:Female; D015171:Ganglionectomy / Q000379:methods; D009498:Neurotoxins / Q000494:pharmacology; D009929:Organ Size; D010306:Parotid Gland / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013363:Submandibular Gland / Q000737:chemistry*; D013373:Substance P / Q000032:analysis*; D013562:Sympathectomy / Q000379:methods; D001743:Urinary Bladder / Q000737:chemistry; D014660:Vasoactive Intestinal Peptide / Q000032:analysis*
D009498:Neurotoxins; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin