RESUMO
Vasoactive intestinal peptide-like and peptide histidine isoleucine-like immunoreactivities were detected in the excretory duct of adult male and female Nippostrongylus brasiliensis, thus indicating the source of these two physiologically active peptides previously isolated from the excretory/secretory products of adult N. brasiliensis. In the nervous system immunoreactivity to both these peptides was confined to females and was found in the neurons of the ovijector associated ganglion. This is consistent with co-synthesis of vasoactive intestinal peptide-like and peptide histidine isoleucine-like peptides which has also been shown to occur in all mammalian vasoactive intestinal peptid-ergic neurons studied to date. However, in addition to this, and in common to some previous studies on helminth vasoactive intestinal peptide and peptide histidine isoleucine immunoreactivities, co-synthesis of the peptides was not indicated in a pair of branched neurons which projected posteriorly and peripherally from the ganglion associated with the ovijector of females and which terminated in two pairs of ganglia also exhibiting vasoactive intestinal peptide-like immunoreactivity only. The position of these ganglia indicated that they innervate muscles close to the body wall and may be responsible for the muscular contractions required for expulsion of eggs from female Nippostrongylus brasiliensis. This is also the first study to successfully detect these peptides in the excretory system of gastrointestinal nematodes.
Assuntos
Neurônios/química , Neuropeptídeos/análise , Nippostrongylus/química , Peptídeo PHI/análise , Peptídeo Intestinal Vasoativo/análise , Animais , Feminino , Imuno-Histoquímica , Masculino , Microscopia Confocal , RatosRESUMO
The distributions of tyrosine hydroxylase (TH), protein gene product (PGP) 9.5, calcitonin gene-related peptide (CGRP), and peptide histidine isoleucine (PHI) have been examined immunohistochemically in the adrenal gland of the snake Waglerophis merremii. The morphology of chromaffin cells and the presence of ganglionic neurons in the gland revealed by means of the glutaraldehyde-silver technique and electron microscopy are also described. Two distinct types of TH-immunoreactive (-IR) cells are present in the dorsal noradrenergic ribbon: small chromaffin cells and a larger type identified as ganglionic neurons. Small, mostly round or fusiform cells often displayed long processes. Ganglionic cells, arranged in patches, had long processes entering the cortex of the gland. Chromaffin adrenergic cells, forming small groups of 4-7 cells, were scattered within the interrenal tissue and had a wide variety of shapes with processes that appeared to contact other chromaffin cells. Bundles of PGP 9.5-IR fibers occurred in the subcapsular zone of the adrenal gland with fibers entering the cortex and dorsal noradrenergic ribbon of the gland. Thick and thin TH-IR fibers were seen. Thick TH-IR fibers were nonvaricose and appeared to originate mainly in ganglionic neurons. Thin TH-IR fibers with small varicosities were numerous in the interrenal tissue and were frequently seen between clusters of adrenergic cells in close apposition to cortical cells and vessels. CGRP-IR fibers were present throughout the entire adrenal gland, whereas PHI-IR fibers had a preferential distribution in the interrenal tissue. Both CGRP- and PHI-IR fibers were closely associated with vessels and cortical cells.