Fernando de Castro and the discovery of the arterial chemoreceptors

Abstract

When de Castro entered the carotid body(CB)field,the organ was considered to be a small autonomic ganglion,a gland,a glomusorglomerulus,or a paraganglion. In his 1928 paper,de Castro concluded:“Insum,the Glomuscarotic umisinnervated by centripetal fibers,whose trophic center sare located in thesensory ganglia of the glossopharyngeal, and not by centrifugal[efferent] or secret o motor fibers a sisthe case for glands ; these are precisely the facts which lead to suppose that the Glomuscaroticumisa sensory organ.”A few pages down,de Castro wrote:“The Glomus represents an organ with multiplereceptors furnished with specialized receptor cells like those of the sensory organs [tastebuds?]...As aplausible hypothesis we propos et hattheGlomuscaroti cum represents a sensory organ, at present the only one in its kind, dedicated to capture certain qualitative variations in the composition of blood, a function that,possibly by are flex mechanism would have an effect on the functionalactivity of other organs... Therefore, thesensory fiber would not be directly stimulated by blood, but via the intermediation of the epithelial cell soft he organ, which, as their structures suggests, possess a secretory function which would participate in the stimulation of the centripetal fibers.”In our article we will recreat et he experiments that allowed Fernando de Castrotoreach this first conclusion. Also, we will scrutinize the natural endowment sand the scientific knowledge that drove de Castrotomaket the triple hypotheses : the CBaschemoreceptor (variationsinbloodcomposition),as a secondary sensory receptor which functioning involves a chemical synapse, and as a center, origin of systemicreflexes. After a brief account of the systemic reflex effects resulting from the CB stimulation, we wil lcomplete our article with a general view of the cellular-molecular mechanisms currently thought to be involved in the functionin go fthis arterial chemoreceptor.