Comparative distribution of urocortin- and CRF-like immunoreactivities in the nervous system of the earthworm Lumbricus terrestris

Corticotropin-releasing factor (CRF) and urocortin (Ucn) are both members of the CRF neuropeptide family. The distribution of Ucn- and CRF-like immunoreactive (ir) structures in the central nervous system of several vertebrate species has been studied, but little is known about that in non-vertebrates. We used a highly specific polyclonal antibody against rat Ucn and CRF to determine and compare the distribution of Ucn- and CRF-like immunoreactivity in the earthworm nervous system. Several Ucn- and CRF-like ir perikarya were described in the cerebral ganglion, subesophageal and ventral cord ganglia. The majority of Ucn-like ir cells were found in the ventral ganglia, whereas CRF-like ir cells were most abundant in the cerebral ganglion. Scattered Ucn- and CRF-like ir varicose fiber terminals were seen in all areas of the earthworm central nervous system. Ucn-like ir cell bodies and fiber terminals were also demonstrated in the pharyngeal wall. No co-localization of Ucn- and CRF-like ir nervous structures were observed. This study provided morphological evidence that Ucn- and CRF-like neurosecretory products exist in the earthworm central nervous system. Furthermore, both the distribution and morphology of Ucn- and CRF-like ir structures were distinct, therefore, it can be hypothesized that these neuropeptides exert different neurendocrine functions in the earthworm nervous system.     

Parvalbumin-immunoreactive material in the earthworm, Lumbricus terrestris

Parvalbumin-like material was localized using an immunoeytochcmieal method, in neurons of the central nervous system and in cells intermingled in the skin of the earthworm. Lumbricus terreslris L. Parvalbumin-immunoreactive material was found in the cytoplasm of perikarya and neutrites, not in the nucleoplasm. In contrast to vertebrates, Lumbricus musculature did not contain parvalbumin-immunoreactive material.     

The nitrogen excretory metabolism of Lumbricus terrestris

The use of the earthworm as a laboratory animal for studying the effects of starvation on nitrogen metabolism is discussed. Simple techniques and methods are presented allowing in vivo physiological responses to be compared with changes in the enzyme potential of gut tissue.     

Occurrence of ceramide-glycanase in the earthworm, Lumbricus terrestris

We have detected the presence of ceramide-glycanase in the earthworm, Lumbricus terrestris. We have also devised a simple method for the preparation of this enzyme from the earthworm. This enzyme cleaved the linkage between the ceramide and the glycan chain in LacCer, GbOse3Cer, GbOse4Cer, GbOse5Cer, GM3, GM2, GM1 and GD1a. By using tritium-labeled GM2 as substrate, the optimum pH of this enzyme was found to be between pH 4 and 4.5. In the earthworm, the ceramide-glycanase was mainly found in the muscle. The intestine was found to contain a very low level of this enzyme. Because of their easy availability, earthworms should become a convenient source for the preparation of ceramide-glycanase.     

The elemental composition of the chloragosomes of two earthworm species (Lumbricus terrestris and Allolobophora longa) determined by electron probe X-ray microanalysis of freeze-dired cryosections

Summary The elemental composition of the chloragosomes of the two earthworm species, one with complex highly active Ca-secreting calciferous glands (L. terrestris) and the other with non-secretory glands (A. longa), was determined by the electron probe X-ray microanalysis of unfixed freeze-dried cryosections. The predominant constituents of the chloragosomes of both species were P, Ca, Zn and S, with lesser quantities of K, Cl and Fe. The most striking species differences in chloragosomal chemistry were the higher concentrations (expressed as relative mass fractions) of P(×2.1), Ca(×1.5), and Zn(×2.3) in L. terrestris, and the much higher S(×19.6) in A. longa. These differences were discussed in relation to the general ecophysiology of the two species, and more specifically in relation to heavy metal uptake and binding.