Localization of somatostatin-, substance P- and calcitonin-like immunoreactivity in the neural ganglion of Ciona intestinalis L. (Ascidiaceae)

Immunoreactive calcitonin in the central nervous system of the pigeon

To determine whether calcitonin (CT) is present in avian central nervous system (CNS), as it has been recently found in the CNS of other species, we studied extracts of pigeon (Columbia livia) brain by immunochemical methods. A sensitive and specific radioimmunoassay for salmon CT was used together with gel filtration and high performance liquid chromatography (HPLC). Extracts of hypothalamus contained 31.5 +/- 9.65 ng/g wet weight as salmon CT-like immunoreactivity while extracts of midbrain and brain stem contained 17.0 +/- 5.00 and 2.85 +/- 2.1 ng/g wet weight respectively. Extracts of whole pituitary gland, other areas of the CNS and vazrious peripheral tissues were below the detection limits of our assay, but salmon CT-like immunoreactivity was present in ultimobranchial gland (UBG), thyroid gland and lung tissue extracts. On Sephadex G-50 chromatography extracts of hypothalamic, midbrain, UBG and thyroid gland gave an immunoreactive peak which co-eluted with synthetic salmon CT. However, on HPLC the material in pigeon hypothalamus, midbrain, UBG and thyroid gland eluted in an identical manner when compared to each other but the major peak was 2 ml after that of synthetic salmon CT. These results clearly show that a salmon CT-like immunoreactive molecule is present in pigeon hypothalamus and midbrain, in addition to its main locations in the UBG and thyroid gland.

Substance P-like immunoreactivity in the nervous system of hydra

Using immunocytochemistry we find substance P-like material in nerve cells of hydra. These nerve cells are situated in the ectoderm of the basal disk and tentacles. Radioimmunoassay of hydra extracts gives dilution curves parallel to that of synthetic substance P, from which it can be calculated that one animal contains at least 0.6 fmol substance P-like immunoreactivity. After chromatography on Biogel P-100, the substance P-like immunoreactivity elutes as a peak in the void volume and a peak at the position of synthetic substance P.

Immunocytochemical identification of neural elements in the central nervous systems of a snail, some insects, a fish, and a mammal with an antiserum to the molluscan cardio-excitatory tetrapeptide FMRF-amide

With an antiserum to the molluscan cardio-excitatory tetrapeptide FMRF-amide neurons and/or nerve fibers were immunocytochemically identified in the central nervous systems of a snail (Lymnaea stagnalis), some insects (Leptinotarsa decemlineata, Periplaneta americana, Locusta migratoria, Pieris brassicae), a fish (Poecilia latipinna) and a mammal (mouse). The fact that immunoreactive material was observed in neurohaemal organs (corpora cardiaca of the insects) as well as in axon terminals ending on other neurons, seems to indicate that this peptide can function as a neurohormone and/or as a neurotransmitter. The results sustain the hypothesis that biologically active peptides have a wide distribution in the animal kingdom.

Substance P-, neurotensin- and bombesin-like immunoreactivities in the gill epithelium of Ciona intestinalis L

Substance P-, neurotensin- and bombesin-like immunoreactivities were localised in some gill epithelial cells in the pharynx of Ciona intestinalis L. No immunoreactivity was obtained with antisera to gastrin, glucagon, insulin, pancreatic polypeptide or calcitonin. Some of the epithelial cells of the gills were shown to be argyrophilic with the Grimelius technique.