Hormone complement of the Cancer productus sinus gland and pericardial organ: An anatomical and mass spectrometric investigation

Abstract

In crustaceans, circulating hormones influence many physiological processes. Two neuroendocrine organs, the sinus gland (SG) and the pericardial organ (PO), are the sources of many of these compounds. As a first step in determining the roles played by hemolymph-borne agents in the crab Cancer productus, we characterized the hormone complement of its SG and PO. We show via transmission electron microscopy that the nerve terminals making up each site possess dense-core and/or electron-lucent vesicles, suggesting diverse complements of bioactive molecules for both structures. By using immunohistochemistry, we show that small molecule transmitters, amines and peptides, are among the hormones present in these tissues, with many differentially distributed between the two sites (e.g., serotonin in the PO but not the SG). With several mass spectrometric (MS) methods, we identified many of the peptides responsible for the immunolabeling and surveyed the SG and PO for peptides for which no antibodies exist. By using MS, we characterized 39 known peptides [e.g., beta-pigment-dispersing hormone (beta-PDH), crustacean cardioactive peptide, and red pigment-concentrating hormone] and de novo sequenced 23 novel ones (e.g., a new beta-PDH isoform and the first B-type allatostatins identified from a non-insect species). Collectively, our results show that diverse and unique complements of hormones, including many previously unknown peptides, are present in the SG and PO of C. productus. Moreover, our study sets the stage for future biochemical and physiological studies of these molecules and ultimately the elucidation of the role(s) they play in hormonal control in C. productus.

The neuroendocrine system of invertebrates: a developmental and evolutionary perspective

“…CHH also affects heart beat and molting. Beside the pericardial organ, the X-organ/sinus gland complex is another source of CHH (Fu et al 2005).…”

Mass Spectral Charting of Neuropeptidomic Expression in the Stomatogastric Ganglion at Multiple Developmental Stages of the Lobster Homarus americanus

“…It is not easy to assign these peaks, especially when the peak cluster of m/z 964.5 is dominated by a peptide from the FaRP family GGRNFLRFamide (m/z 965.54). 23 These two tachykinin peptides APSGFLGM(O)Ramide (m/z 950.49) and TPSGFLGMRamide (m/z 964.5) were shown to be present in the brain of the American lobster, but neither peptide was reported in the STG previously. Our study thus represents the first report about the existence of these two tachykinins in the STG based on similar CE migration patterns.…”

Nitric oxide production and sequestration in the sinus gland of the green shore crab, Carcinus maneas

“…As areas of strong fluorescence occurred throughout the optical sections of the z-stack, the 1 h loading period was sufficient time for the CuFL to penetrate to the interior of the SG. The SG is structured as a network of groups with swollen axon termini separated by glial cell projections (Fu et al, 2005). This is apparent in the cell viability images, in which the nuclei of glial and other supporting cells surround axon termini that lack nuclei (Fig.…”

“…We conclude that the site of NO production, storage and release is confined to supportive structures, and areas within the SG lacking NO-FL fluorescence are axon termini. Additionally, several terminal types are present in the SG (Fu et al, 2005), therefore areas of NO-FL fluorescence may identify supportive cells near terminals from which neuropeptide release is NO dependent, and terminals adjacent to areas lacking NO-FL rely on another mechanism for peptide release.…”