IGF-II-like immunoreactivity in human tissues, neuroendocrine tumors, and PC12 cells.

We looked for cells that reacted with monoclonal antibodies against rat insulin-like growth factor II (IGF-II). We found them in human fetal kidneys in the 14th week of gestation and in adult adrenal medullas but not in human liver, pancreas, pituitary gland, or thymus. Every pheochromocytoma in a group of 20 had IGF-II-like immunoreactive cells, as did three out of four ganglioneuroblastomas (one of which was heterotransplantable in athymic nude mice) and one carotid body tumor.

CGRP-immunoreactive sensory nerve fibers in the submandibular gland of the rat.

Indirect immunofluorescence technique was used to study the occurrence and distribution of CGRP immunoreactivity in the submandibular gland of normal rats and after unilateral sensory and sympathetic denervations. In normal rats, CGRP-immunoreactive nerve fibers and nerve trunks were seen around or in close contact with interlobular salivary ducts as well as around small blood vessels of the gland. Occasionally, CGRP-immunoreactive nerve fibers were also detected between or around the acini of the gland.

Immunohistochemical analysis of chromogranin A and multiple peptides in the mammalian Merkel cell: further evidence for its paraneuronal function?

By the use of light microscopic immunohistochemistry, epidermal Merkel cells have been examined for the coexistence of some neuropeptides and chromogranin A (CGA). Peptide and CGA-immunophenotypes were similar in adult Merkel cells but variable in fetal skin, where CGA preceded the expression of peptides which were partly expressed only in a subpopulation of Merkel cells from hair follicles. Thus, only Substance P (SP) and calcitonin gene-related peptide (CGRP) were expressed in a subpopulation of Merkel cells from hair follicles.

Immunocytochemical demonstration of IGF-II-like immunoreactivity in human paraganglioma of the craniocervical region.

Insulin-like-growth factor (IGF)-II-like immunoreactivity was examined in two carotid bodies and six extra-adrenal paragangliomas with use of monoclonal antibody against rat IGF-II, which crossreacts with human IGF-II. Chief cells but not sustentacular cells of the carotid body were positive at about 10% in one case and less than 1% in another case. Among four carotid body tumours, a possible vagal body tumour and one glomus jugulare tumour, all but the glomus jugulare tumour exhibited positive tumour cells irrespective of histological variations.

Galanin and vasoactive intestinal polypeptide are colocalised with classical pituitary hormones and show plasticity of expression.

The identity of galanin- and vasoactive intestinal polypeptide-(VIP) immunoreactive (IR) cells in the rat anterior pituitary was investigated using immunocytochemistry and, since levels of both peptides are stimulated by oestrogen, the effect of oestrogen treatment and gonadectomy on the expression of both peptides was examined. In normal male rats, few galanin-IR and very few VIP-IR cells were found. Colocalisation studies performed on 2-microns serial paraffin sections revealed that in these animals galanin IR was present in somatotrophs and thyrotrophs.

Recent advances in brain-gut hormones.

Although recent advances in gene technology have made it possible to produce peptides and proteins by the recombinant technique, chemical synthesis either by the solution or by the solid-phase technique is still only a method of choice for the syntheses of a brain-gut hormone and its superagonist and/or antagonist. In addition, synthetic replicates of brain-gut hormones, their analogus and fragments or their precursor-related peptides are important haptenic immunogens to produce region-specific antisera to the respective peptides. In the present study, antisera against proglucagon and pro-LH-RH related peptides were proved to be useful not only for identifying hormone-producing cells, but also for demonstrating the post-translational biosynthetic processing in the cells.

Cross-reaction of two different somatostatin antisera with calcitonin gene-related peptide.

Two different anti-somatostatin antisera, R-101 and OAL-273, cross-react with rat calcitonin gene-related peptide (1-37) (CGRP). CGRP amounts, in excess of 6.25 x 10(-9) M, cross-react with R-101 in the somatostatin radioimmunoassay.

Transient involvement of enkephalins in both the sympathetic and parasympathetic innervations of the submandibular gland of rats. Light- and electron-microscopic immunocytochemical study.

A time course study with enkephalin (Enk)-like immunoreactivity has revealed that nerve fibers intensely immunoreactive for Enk-8 appeared transiently only during the postnatal week 2 and 4 within the acini as well as in the inter- and intralobular connective tissues of the submandibular gland of rats. At these stages numerous nerve fibers immunoreactive for tyrosine hydroxylase (TH) appeared also in the inter- and intralobular connective tissues and within the acini. Coincidently with these postnatal stages, abundant Enk-immunoreactive principal ganglion cells appeared in the superior cervical ganglion.

Actions of galanin fragments on rat, guinea-pig, and canine intestinal motility.

The 1-20 fragment of synthetic porcine galanin, prepared by tryptic digestion of the intact molecule, was equipotent to synthetic porcine galanin 1-29 in the smooth muscle actions of exciting the rat jejunal longitudinal muscle in vitro and inhibiting circular muscle contractions of the canine small intestine in vitro and in vivo, but was less potent in inhibiting nerve-stimulated contractions of the guinea-pig taenia coli. Fragment 21-29 was effective at high doses only in the canine ileum. Activity of galanin 1-11 was greatly reduced in the dog in vivo.

Colocalization of GABA and [Met]enkephalin-Arg6-Gly7-Leu8 in the rat cerebellum.

The distribution of [Met]enkephalin-Arg6-Gly7-Leu8-like immunoreactivity (MEAGL-LI) in the rat cerebellum was investigated by peroxidase anti-peroxidase immunocytochemistry using specific antiserum against MEAGL. MEAGL-LI positive neuronal perikarya were distributed in the granular layer, and they seemed to correspond to Golgi cells from their size and location. In addition, diffusely and weakly stained neuronal perikarya were also observed in the molecular layer.

Contribution of galanin to non-cholinergic, non-adrenergic transmission in rat ileum.

1. We examined the possibility that the neuropeptide, galanin, may act as a transmitter in longitudinal muscle isolated from the rat ileum. 2.

Presence and coexistence of chromogranin A and multiple neuropeptides in Merkel cells of mammalian oral mucosa.

By the use of light microscopic (LM) immunohistochemistry, Merkel cells of the mammalian oral mucosa have been examined for the presence and coexistence of some neuropeptides and of the neuroendocrine marker chromogranin A (CG-A). Peptide and CG-A immunophenotypes of oral Merkel cells were found to vary between species and to depend on the developmental stage, as exemplarily revealed in the pig. Oral Merkel cells of adult cat, mouse and pig but not those of adult guinea pig stained for calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI).

Co-localization of substance P and Met-enkephalin-Arg6-Gly7-Leu8 in the intraspinal neurons of the rat, with special reference to the neurons in the substantia gelatinosa.

A double-labeling immunofluorescence technique was employed to investigate the co-localization of the functionally antagonistic neuropeptides, substance P and enkephalins, within intraspinal neurons of the rat. Anti-Met-enkephalin-Arg6-Gly7-Leu8 (Enk-8) antiserum was used as a marker of the preproenkephalin A neuron system. The observations were focused on the lumbar spinal cord.

Stimulation of growth hormone secretion by central administration of atrial natriuretic polypeptide in the rat.

Intracerebroventricular (icv) injection of alpha-human atrial natriuretic polypeptide (alpha hANP) or alpha-rat ANP (0.6 and 3 nmol/rat) elicited an increase in plasma GH levels both in conscious freely moving rats and in urethane-anesthetized rats when given at the trough of spontaneous GH secretion. Antiserum specific for rat GRF did not affect the plasma GH increase induced by icv injection of alpha hANP.

Pharmacology and molecular identification of vasoactive intestinal peptide (VIP) receptors in normal and cancerous gastric mucosa in man.

In human antral membranes, VIP and its natural analogs inhibited the binding of HPLC-purified 125I-VIP, according to the following order of potency: VIP greater than rh GRF greater than helodermin greater than r PHI greater than PHM greater than p PHI greater than hp GRF greater than h, p secretin. No specific binding was detected in plasma membranes purified from the human fundus. In human antral membranes, Scatchard plots were compatible with the existence of two classes of VIP receptors, the first class with high affinity and low binding capacity (Kd = 0.

Interaction between vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in stimulating the secretion of prolactin from rat anterior pituitary cells in vitro.

Interaction between vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in regulating the secretion of prolactin (PRL) from the pituitary was investigated in the rat in vitro using two different methods: (1) short incubation of anterior pituitary cells and (2) superfusion of the pituitary cell column. PRL levels in the incubation medium were raised by addition of either VIP or PHI in concentrations of 10(-9) M to 10(-7) M in a dose-related manner. When both peptides were simultaneously added, additive stimulating effect on PRL release was obtained below the VIP concentration of 10(-7) M, in which no additive effect of PHI was revealed.

Depletion of gastrin-releasing peptide (GRP) from nerves in the gastric body of rats with experimental ulcers. An immunohistochemical study.

A predominant population of mucosal nerves in the mammalian gastric body has been known to contain large amounts of gastrin-releasing peptide (GRP). The present immunohistochemical study demonstrates the depletion of GRP immunoreactivity from nerves in the oxyntic mucosa of rats with ulcers induced by restraint plus water immersion. Depletion of GRP occurred in a major part of the nerves after 3 h exposure to the stress, and after 6 h exposure only a few nerve fibers could be recognized.

Galanin stimulates the release of vasoactive intestinal polypeptide from perifused hypothalamic fragments in vitro and from periventricular structures into the cerebrospinal fluid in vivo in the rat.

Intracerebroventricular injection of galanin (2 micrograms/rat) raised plasma prolactin (PRL) levels in the rat, which was accompanied by an increase in immunoreactive vasoactive intestinal polypeptide (VIP) in the cerebrospinal fluid (CSF). Immunoreactive VIP release from superfused rat hypothalamic fragments in vitro was dose-relatedly stimulated by galanin (10(-7) and 10(-8) M). PRL release from superfused rat anterior pituitary cells was stimulated by TRH (10(-8) M) but not affected by galanin (10(-7) to 10(-5) M).

Is helodermin produced by medullary thyroid carcinoma cells and normal C-cells? Immunocytochemical evidence.

Helodermin is a VIP/secretin-like 35-amino acid peptide originally isolated from the venom of the lizard Gila monster. Recently, helodermin-immunoreactive material was demonstrated in mammalian salivary glands, brain and gut. In the present study 8 human medullary thyroid carcinomas as well as 4 normal thyroid glands were examined immunocytochemically for the presence of helodermin using an antiserum raised against helodermin-(5-35) that does not cross-react with VIP or secretin.

Interaction of growth hormone-releasing factor and somatostatin on ulcer healing and mucosal growth in rats: role of gastrin and epidermal growth factor.

Growth hormone-releasing factor (GRF) was reported to possess the growth-promoting action on the gastroduodenal mucosa that can be augmented by removal of endogenous somatostatin. Since mucosal proliferation was considered to contribute to healing of chronic gastroduodenal ulcerations, we designed the study to determine the interaction of GRF and somatostatin on the healing rate of acetic acid-induced chronic gastric and duodenal ulcers and on the growth of gastroduodenal mucosa in rats. GRF injected subcutaneously twice daily at 100 micrograms/kg/day for 7 days resulted in a significant enhancement of healing rate of both gastric and duodenal ulcerations and this was accompanied by a significant increase in the weight of the mucosa and the contents of RNA and DNA.

Further study of effects of synthetic peptides on identifiable giant neurones of an African giant snail (Achatina fulica Férussac).

1. Effects of the following peptides at 10(-4) M on identifiable giant neurones of Achatina fulica Férussac were examined: physalaemin, eledoisin, bradykinin, neurokinin A, neurokinin B, neuromedin B, gastrin releasing peptide decapeptide (neuromedin C), gastrin releasing peptide (14-27), cholecystokinin tetrapeptide, cholecystokinin octapeptide, thyrotropin releasing hormone, Arg-vasotocin, gamma-melanocyte stimulating hormone. 2.

Effects of synthetic biologically active peptides on giant neurones identified in the left buccal ganglion of an African giant snail (Achatina fulica Férussac).

1. The effects of synthetic biologically active peptides, including Met-enkephalin, substance P, oxytocin, Arg-vasopressin, proctolin and FMRFamide, on the following four buccal neurones were examined: d-LBAN (dorsal-left buccal anterior neurone), d-LBMN (dorsal-left buccal medial neurone), d-LBCN (dorsal-left buccal central neurone) and d-LBPN (dorsal-left buccal posterior neurone). These peptides were examined at 10(-4) M.