title: Novel findings in the cephalic phase of digestion: a role for microcirculation?
abstract: The cephalic phase of digestion (CPD) has been extensively investigated in terms of digestion and metabolism. Nevertheless, microcirculatory changes required to prepare peripheral tissues in order to dispose nutrients have never been assessed. In this study, microvascular function has been evaluated to determine its behavior and potential association to hormonal secretions during CPD. Thirty-nine healthy male subjects, 23.4 ± 0.5 years (mean ± SD) and BMI of 23.3 ± 2.3 kg/m(2), were randomized into receiving cognitive-sensorial stimuli to elicit CPD (CPD group, n=20) or not (control group, n=19), after a 12-h overnight fast. Main outcomes were differences in resting and peak functional capillary density (FCD, cap/mm(2)); resting red blood cell velocity (RBCV), peak RBCV (RBCV(max)) and time taken to reach it (TRBCV(max)); peak flow and vasomotion, before and after CPD and their associations with insulin and/or pancreatic polypeptide (PP). In the CPD group, basal FCD (24.9 ± 7.6 to 28.3 ± 8.1, p=0.005), peak FCD (27.8 ± 6.3 to 32.6 ± 7.1, p=0.002), RBCV (0.306 ± 0.031 to 0.330 ± 0.027 mm/s, p=0.005), RBCV(max) (0.336 ± 0.029 to 0.398 ± 0.292 mm/s, p=0.005) and peak flow (23.5 ± 14.3 to 26.9 ± 15.8 PU, p<0.01) increased while TRBCV(max) decreased (4.9 ± 1.5 to 3.5 ± 1.2s, p=0.01). No significant changes could be detected in the control group. Groups have not presented differences for insulin, but PP significantly increased in the CPD group and was positively associated to basal FCD increase (rho=0.527, p=0.03). In conclusion, neurally-mediated anticipatory responses of digestion elicited functional capillary recruitment associated to PP in healthy men, suggesting a precocious role for microcirculation in the physiology of digestion and nutrient homeostasis.
authors.affiliation: State University of Rio de Janeiro, Biomedical Center, Clinical and Experimental Research Laboratory on Vascular Biology (BioVasc), Rio de Janeiro, RJ, Brazil.
authors.forename: Caroline
authors.initials: C
authors.lastname: Buss
authors.forename: Luiz Guilherme
authors.initials: LG
authors.lastname: Kraemer-Aguiar
authors.forename: Priscila A
authors.initials: PA
authors.lastname: Maranhão
authors.forename: Carolina
authors.initials: C
authors.lastname: Marinho
authors.forename: Maria das Graças C
authors.initials: Md
authors.lastname: de Souza
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wiernsperger
authors.forename: Eliete
authors.initials: E
authors.lastname: Bouskela
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D003463:Cues; D004063:Digestion / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000008:administration & dosage / Q000097:blood; D007478:Iontophoresis / Q000379:methods; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D010191:Pancreatic Polypeptide / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D012867:Skin / Q000098:blood supply; D012879:Skin Physiological Phenomena
chemical_list: D007328:Insulin; D010191:Pancreatic Polypeptide