Biomedical subjects

F Sundler

Publications and source records attributed to F Sundler.

At least 163 records · Page 9Linked to original sources

PubMed1994

Neuronal pathways to the rat conjunctiva revealed by retrograde tracing and immunocytochemistry.

The origin and neuropeptide content of nerve fibres in the rat conjunctiva were studied by retrograde tracing and denervations in combination with immunocytochemistry. Immunocytochemistry revealed nerve fibres containing neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), helospectin, substance P (SP), and calcitonin gene-related peptide (CGRP) around blood vessels, smooth muscle bundles and glands. Removal of the sphenopalatine ganglion eliminated the majority of the VIP-, PHI- and helospectin-containing fibres. Sympathectomy eliminated the majority of the NPY-containing fibres in the conjunctiva. Removal of both the sphenopalatine ganglion and the superior cervical ganglion led to further reduction of the NPY fibres. Injection of the retrograde tracer True Blue into the conjunctiva resulted in the appearance of labelled cell bodies in the trigeminal ganglion, the sphenopalatine ganglion, the superior cervical ganglion, and the ciliary ganglion. Judging from the number of labelled nerve cell bodies, the superior cervical ganglion contributes most to the innervation. These results indicate that the majority of NPY-containing nerve fibres in the conjunctiva derives from the superior cervical ganglion (sympathetic nerve supply). Most of the VIP- and a minor population of the NPY-containing fibres in the conjunctiva originate in the sphenopalatine ganglion (parasympathetic nerve supply). A sparse amount of VIP- and NPY-containing fibres derives from the ciliary ganglion. Nerve fibres containing SP and/or CGRP emanate from the trigeminal ganglia (sensory nerve supply). Together the findings indicate that several ganglia project to the conjunctiva and that many neuropeptides may be involved in the control of conjunctival activity.

Animals↗

PubMed1994

Microcirculation-derived factors in airway epithelial repair in vivo.

Airway epithelial repair, by cell migration over a denuded, intact basement membrane, occurs rapidly in vivo. The present study examines microcirculation-derived factors in the reepithelialization process in the guinea pig. A well-defined tracheal zone was gently deepithelialized; no bleeding occurred and the basement membrane was left intact. Plasma exudation was visualized by use of iv colloidal gold (diameter: 5 nm) or fluoresceinisothiocyanate-labeled dextran. Scanning and transmission electron microscopy confirmed the migration of epithelial cells and, additionally, allowed us to examine the presence of an extracellular matrix gel and leukocytes on the denuded basement membrane. Fibronectin was analyzed by immunocytochemistry. Following epithelial removal plasma promptly extravasates and produces a fibrin-fibronectin gel to cover the denuded basement membrane. Epithelial cells dedifferentiate, flatten, and migrate rapidly (several micron/min) beneath the plasma-derived gel. Within 30 min the gel contains numerous leukocytes, some of which are eosinophils. Plasma exudes into the gel until about 8 hr by which time the entire denuded zone (800 microns) is covered by squamous epithelium. The fibrin-fibronectin gel is suggested to be exclusively plasma-derived. In conclusion, reepithelialization in vivo occurs beneath a gel containing adhesive plasma proteins and leukocytes. We suggest that a plasma exudate provides immediate cover of denuded airway basement membrane and that plasma- and leukocyte-derived factors contribute essentially to reepithelialization in vivo.

Animals↗

PubMed1994

Origin and peptide content of nerve fibers in the nasal mucosa of rats.

Injection of the retrograde neuronal tracer True blue into the anterior-lateral part of the nasal mucosa of rats labeled nerve cell bodies in the superior cervical ganglion, the sphenopalatine ganglion, the otic ganglion and the trigeminal ganglion on the ipsilateral side. In the superior cervical ganglion, the sphenopalatine ganglion and the trigeminal ganglion on the contralateral side, very few nerve cell bodies were labeled, indicating that these ganglia provide minor contributions only. The number of labeled cell bodies indicates that the superior cervical ganglion, the sphenopalatine ganglion and the trigeminal ganglion contribute most to the innervation of the nose, while the contribution from the otic ganglion is minor. Cell bodies in the superior cervical ganglion harbored noradrenaline (NA) or NA/neuropeptide Y (NPY); in the sphenopalatine ganglion vasoactive intestinal peptide (VIP) or VIP/NPY; in the otic ganglion VIP, VIP/NPY or VIP/substance P (SP) and in the trigeminal ganglion calcitonin gene-related peptide (CGRP) or CGRP/SP. The results from denervations and tracer experiments suggest that all NA-containing and the majority of NPY-containing fibers in the nasal mucosa are derived from the superior cervical ganglion (sympathetic nerve supply). VIP- and VIP/NPY-containing fibers originate from the sphenopalatine and optic ganglia (parasympathetic nerve supply). Nerve fibers containing CGRP and CGRP/SP emanate from the trigeminal ganglion (sensory nerve supply).

Animals↗

PubMed1994

Basement membrane components of bronchial epithelium in humans suffering from chronic nonspecific lung diseases.

Collagen IV and laminin are important constituents of the basement membrane (BM). By use of immunocytochemistry we examined the occurrence and distribution of these two components in the BM beneath normal, mucoid and metaplastic epithelium of large bronchi in 22 adults suffering from chronic nonspecific lung diseases. Both collagen IV and laminin were expressed as a thin and continuous layer beneath the epithelium in most tissue specimens with normal epithelium. In a few specimens the layer showed interruptions with a patchy distribution of the immunoreactivity. Three patterns of distribution of BM components were found under the metaplastic epithelium. Total absence of immunoreactive collagen IV and laminin was the most common variant. Weak and scarce staining for both proteins in the BM characterized the second pattern. The third variant showed strong collagen IV immunoreactivity but lack of laminin. The BM beneath the mucoid epithelium was characterized by irregular distribution of collagen IV and laminin. We suggest that the occurrence and distributional pattern of the BM components are related to the type of overlying epithelium and connected with an altered synthesis of these components.

Adult↗

PubMed1994

Acute responses of rat stomach enterochromaffinlike cells to gastrin: secretory activation and adaptation.

BACKGROUND/AIMS: Evidence for gastrin-induced histamine secretion from isolated rat enterochromaffinlike (ECL) cells was presented recently. We have investigated the gastrin-evoked secretory activation and adaptation of ECL cells in intact rats over a time span of a few minutes to several hours. METHODS: Fasted rats received a maximally effective dose of synthetic human Leu15-gastrin-17 by continuous intravenous infusion. ECL cell ultrastructure and ECL cell-related parameters (e.g., mucosal histamine and pancreastatin concentrations, histidine decarboxylase [HDC] activity, and messenger RNA [mRNA] concentration) were analyzed. RESULTS: Gastrin reduced the number of cytoplasmic vesicles in ECL cells while reducing the concentrations of histamine and pancreastatin in the oxyntic mucosa. The effects were maximal within a few hours after the start of gastrin infusion. The concentration of pancreastatin in serum was elevated for the duration of the study. The mucosal concentrations of histamine and pancreastatin returned to prestimulation values after 4-6 hours. The HDC activity and mRNA concentration increased progressively until after 6-8 hours of gastrin infusion. CONCLUSIONS: Gastrin promptly degranulates the ECL cells, releasing histamine and pancreastatin from the vesicles. Synthesis of histamine and pancreastatin is accelerated, a process associated with renewal of vesicles. The increase in HDC activity and mRNA concentration continues for several hours after restoration of the vesicles.

Adaptation, Physiological↗

PubMed1994

Islet amyloid polypeptide is expressed in endocrine cells of the gastric mucosa in the rat and mouse.

BACKGROUND/AIMS: Islet amyloid polypeptide (IAPP) or amylin is a novel islet hormone candidate with a suggested role in the regulation of glucose homeostasis and the pathogenesis of non-insulin dependent diabetes mellitus. Occurrence of IAPP in the gastrointestinal tract of rats and humans has also been shown. The expression of IAPP in the stomach of the rat and mouse and the possible colocalization of IAPP and known gastric hormones were investigated in this study. METHODS: In situ hybridization, immunofluorescence, and combined in situ hybridization and immunocytochemistry were used. RESULTS: IAPP messenger RNA and IAPP-like immunoreactivity were shown in the same endocrine cells in the antrum and fundus of the rat and in the antrum of the mouse. IAPP was expressed in a major population of somatostatin-immunoreactive cells as well as in small populations of gastrin- and peptide YY-immunoreactive cells. CONCLUSIONS: Our results establish the synthesis and storage of IAPP in gastric endocrine cells in the rat and mouse. The extensive colocalization of IAPP with somatostatin and to a lesser extent with gastrin and peptide YY suggests that IAPP may modulate endocrine activity in the gastric mucosa in a paracrine and/or autocrine mode.

Amyloid↗

PubMed1994

Chromogranin A and B in neuronal elements in Hirschsprung's disease: an immunocytochemical and radioimmunoassay study.

Chromogranin A and B (CAB) occur in several peptide hormone-producing cells and in neurons of the brain. The aim of the present study was to investigate the possible neuronal localization of these chromogranins in the ganglionic and aganglionic bowel in Hirschsprung's disease by immunocytochemistry and radioimmunoassay, using antibodies recognizing either chromogranin A or both chromogranin A and B. Further, the coexistence of chromogranins and other neuronal constituents was studied. CAB were found in nerve fibers and occasionally in nerve cell bodies of submucous and myenteric ganglia in the ganglionic bowel, indicating that at least a population of chromogranin-immunoreactive nerve fibers is intrinsic in origin. CAB-immunoreactive fibers were numerous in the muscle layers of the aganglionic segment. These fibers contained tyrosine hydroxylase (TH), which indicates that they are adrenergic, in both ganglionic and aganglionic bowel. In the muscle layers of aganglionic (but not ganglionic) bowel, chromogranin A coexisted with galanin, neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP). The concentration of CAB in smooth muscle specimens was higher in the aganglionic bowel than in the ganglionic bowel. Thus, chromogranins are present in the human enteric gut hyperinnervating the aganglionic bowel of Hirschsprung's disease.

Chromogranin A↗

PubMed1994

NOS-containing neurons in the rat gut and coeliac ganglia.

Nitric oxide (NO) is considered an important inhibitory neurotransmitter in the gut. Nitric oxide synthase (NOS)-containing neurons were visualized by immunocytochemistry using antibodies against neuronal NOS in the oesophagus, the gastrointestinal tract and the coeliac ganglion of rat. NOS-containing nerve cell bodies were numerous in the myenteric but fewer in the submucous ganglia all along the gut. Synthesis of NOS in enteric nerve cell bodies was confirmed by in situ hybridization, demonstrating the presence of NOS mRNA. Varicose nerve fibers formed extensive networks in the circular smooth muscle and the myenteric ganglia. The pyloric sphincter contained abundant NOS-containing nerve fibers. NOS-containing nerve terminals were frequently found around the Brunner glands in the duodenum; scattered nerve terminals occurred in the gastric and colonic mucosa and around blood vessels in the submucosa all along the gut. The neuronal cell bodies in the coeliac ganglion were non-immunoreactive but frequently surrounded by baskets of NOS-immunoreactive nerve fibers. Double staining for NOS and neuropeptides in oesophagus, stomach and small and large intestine revealed that a small subpopulation of the NOS-containing nerve cell bodies stored in addition vasoactive intestinal peptide (VIP), and in oesophagus, stomach and small intestine also neuropeptide Y (NPY). However, NOS-containing nerve terminals, particularly those in the circular muscle of the gut, frequently contained VIP throughout the gut; in the oesophagus, stomach and the small intestine they contained also NPY.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Oxidoreductases↗

PubMed1994

Distribution, origin and projections of nitric oxide synthase-containing neurons in gut and pancreas.

Nitric oxide has been put forward as an important inhibitory neurotransmitter in the gut. Nitric oxide synthase-containing neurons were visualized by immunocytochemistry using antibodies against neuronal nitric oxide synthase or by beta-nicotinamide adenine dinucleotide phosphate diaphorase staining in whole mounts and cryostat sections from the gastrointestinal tract and pancreas of several mammals (mouse, rat, hamster, guinea-pig, cat and man). Nitric oxide synthase-containing neuronal cell bodies were numerous in the myenteric but fewer in the submucous ganglia all along the gut of all species. Varicose nerve terminals formed extensive networks in the circular smooth muscle and the myenteric ganglia. Nitric oxide synthase-containing nerve terminals were frequently found around the Brunner glands in the duodenum; scattered nerve terminals were also found in the gastric and colonic mucosa and around blood vessels in the submucosa all along the gut. In the rat small and large intestine nitric oxide synthase-containing submucous neurons terminated within the mucosa/submucosa and nitric oxide synthase-containing myenteric neurons issued short descending projections, approximately 3 mm, to the smooth muscle and other myenteric ganglia. In the pancreas of all species nitric oxide synthase-containing nerve cell bodies were regularly seen in intrapancreatic ganglia. Positive nerve fibers were mainly found within nerve trunks in interlobular spaces and as delicate fibers within the islets. Double staining for nitric oxide synthase and neuropeptides in intestine and pancreas of rat, guinea-pig and man revealed that only occasionally the nitric oxide synthase-containing nerve cell bodies stored in addition vasoactive intestinal peptide and neuropeptide Y, or enkephalin. However, nitric oxide synthase-containing nerve terminals, particularly those in the circular muscle of the gut, frequently contained vasoactive intestinal peptide/neuropeptide Y (rat and man) or vasoactive intestinal peptide/enkephalin (guinea-pig). In intrapancreatic ganglia few nitric oxide synthase-containing nerve cell bodies were also vasoactive intestinal peptide-immunoreactive. Coexistence of nitric oxide synthase and vasoactive intestinal peptide in nerve terminals could here be detected around blood vessels and interlobular ducts. The distribution of nitric oxide synthase indicates a major role of nitric oxide in the regulation of gut motility; a role in the regulation of blood flow and secretion in both gut and pancreas is also likely.

Amino Acid Oxidoreductases↗

PubMed1994

Pituitary adenylate cyclase activating polypeptide expression in sensory neurons.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a novel vasoactive intestinal peptide (VIP)-like peptide isolated from ovine hypothalami. The presence of PACAP-like immunoreactivity was recently demonstrated in nerve cell bodies of sensory ganglia in the rat. Since PACAP belongs to a large family of chemically related neuropeptides, we have, in the present study, tried to establish the synthesis of PACAP in neurons of sensory ganglia, using in situ hybridization with a 35S-labelled oligonucleotide probe complementary to PACAP mRNA. The expression of PACAP was compared to that of calcitonin gene-related peptide (CGRP) using a radiolabelled CGRP oligonucleotide probe. The PACAP probe labelled small to medium-sized neurons in the trigeminal ganglion and dorsal root ganglia at different levels, indicating the presence of PACAP mRNA. The CGRP probe labelled nerve cell bodies of varying size, outnumbering those labelled by the PACAP probe. In dorsal root ganglia, cells expressing PACAP constituted c. 10% and those expressing CGRP 46% of the total number of nerve cell bodies. Expression of PACAP was seen in a small subpopulation of cells expressing CGRP. We conclude that PACAP is synthesized in a subpopulation of neurons of sensory ganglia in the rat. Therefore, the recently described effects of PACAP--cutaneous vasodilation, potentiation of oedema formation and depression of nociceptive spinal reflexes--may be physiological and related to neurogenic inflammation and modulation of pain transmission.

Animals↗

PubMed1994

Pancreatic peptide YY in alloxan diabetic mice.

Peptide YY (PYY) immunoreactive material was detected in the splenic and duodenal portions of the adult mouse pancreas, using immunocytochemical and immunochemical methods. Cells displaying PYY immunoreactivity generally occurred at the islet periphery. Double immunostaining enabled localization of PYY to a major subpopulation of the glucagon cells and to subpopulations of the pancreatic polypeptide (PP) cells and the somatostatin cells. In contrast, no PYY immunoreactivity occurred in the insulin cells. In alloxan-treated hyperglycemic mice, PYY immunoreactive cells were increased in number and distributed throughout the islets, in parallel with the glucagon, PP, and somatostatin cells. Analysis by radioimmunoassay indicated a significant increase in the concentration of pancreatic PYY after alloxan treatment in the splenic portion of the pancreas, but not in the duodenal portion. Pancreatic glucagon concentrations were not significantly changed. It is concluded that the islet content of PYY increases in alloxan diabetes, which might contribute to the accompanying alterations in islet function.

Alloxan↗

PubMed1994

Developmental studies on vasoactive intestinal peptide, substance P and calcitonin gene-related peptide in salivary glands of postnatal rats.

The development of vasoactive intestinal peptide, substance P and calcitonin gene-related peptide in parotid, submandibular and sublingual glands of the male rat was followed by immunochemistry and immunocytochemistry. The total amounts of these peptides increased in surges during the first 8 weeks of the animal's life; one within 2-4 weeks and the other beginning 1-2 weeks later. Nerve fibres containing these peptides were present at birth showing a pattern of distribution similar to that in adults. During the first 4 weeks the nerve fibres increased in number.

Animals↗

PubMed1994

Pituitary adenylate cyclase-activating peptide in the adrenal gland of mammals: distribution, characterization and responses to drugs.

The occurrence, cellular distribution and nature of the 27-amino acid form of pituitary adenylate cyclase-activating peptide (PACAP-27) in the adrenal glands of mammals was investigated by means of immunohistochemistry, radioimmunoassay and chromatography. The concentrations (pmol/g wet weight) of PACAP-27-like immunoreactivity (LI) varied considerably between the species examined: mouse (n = 8), 12.1 +/- 2.0; hamster (n = 4), 9.1 +/- 1.5; rat (n = 13), 2.0 +/- 0.3; cow (n = 3), 0.8 +/- 0.1, and pig (n = 5), 0.7 +/- 0.1. Upon HPLC, the immunoreactivity in extracts of rat, mouse and hamster adrenals coeluted with synthetic PACAP-27 while the immunoreactivity in extracts of cow and pig adrenals eluted as less hydrophobic material. Immunohistochemistry revealed the presence of PACAP-27-LI in the noradrenaline-storing chromaffin cells of the adrenal medulla. No nerve fibers exhibiting PACAP-27-LI could be detected. The effects of drug administration in vivo on the stores of PACAP-27-LI in the rat adrenal were studied and compared with the effects on the adrenal stores of neuropeptide Y (NPY)-LI. Splanchnic activation following insulin-induced hypoglycemia elicited a 41% depletion of NPY-LI 2 h after insulin injection, while the concentrations of PACAP-27-LI remained unchanged. Two days after reserpine administration the stores of PACAP-27-LI and NPY-LI were depleted by 62 and 41%, respectively. Two days later, the concentrations of NPY-LI were increased to 216% of controls, while the concentrations of PACAP-27-LI were similar to that of controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗

PubMed1994

ECL cells: biology and pathobiology.

During recent years, the so-called ECL cells of the acid-producing part of the stomach have attracted much attention, mainly due to the fact that mice and rats were found to develop gastric carcinoids (ECL cell tumors) following life-long treatment with blockers of acid secretion. These observations touched off concern about the safety of the long-term clinical use of such drugs. The ECL cells are the predominant endocrine cell population in the oxyntic mucosa. They produce histamine, chromogranin A/pancreastatin and an as yet unidentified peptide hormone. They respond to gastrin by the release of secretory products; more long-term responses include adaptation to the gastrin stimulus, hypertrophy and hyperplasia. Intravenous infusion of maximally effective doses of gastrin promptly reduced the number of cytoplasmic vesicles in the ECL cells and their content of histamine and pancreastatin. Despite the ongoing infusion of gastrin, the number of vesicles and the content of histamine and pancreastatin were back to normal 4-6 h after the start of the infusion. The histidine decarboxylase (HDC) activity and HDC mRNA level increased progressively until plateaus were reached after 6-8 h of gastrin infusion. The size of the ECL cells started to increase about 4 days after the start of a subcutaneous gastrin infusion (resulting in half-maximally effective serum gastrin concentrations). The ECL cell size reached maximum after about 2 weeks and then remained at this level.The number of cytoplasmic vesicles was increased; this effect seemed to reach a maximum after 1-2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Mucosal nitric oxide may tonically suppress airways plasma exudation.

In a search for airway epithelial mechanisms that may affect the subepithelial microcirculation, we examined plasma exudation responses to NG-nitro-L-arginine-methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor. L-NAME was applied topically on the tracheal mucosa of guinea pigs that had previously received 125I-albumin and/or colloidal gold particles (5 nm) intravenously. Luminal entry of plasma was determined by the levels of 125I-albumin in tracheal lavage fluid. Topical L-NAME (2.2, 9, and 22 mumol), but not intravenous L-NAME (375 mumol/kg), produced plasma exudation into the airway lumen (p < 0.01 to p < 0.001). The L-NAME enantiomer NG-nitro-D-arginine-methyl ester (D-NAME, 9 mumol) produced no exudative response. Coadministration of L-arginine (27 mumol) abolished the L-NAME-induced exudation. The extravasated plasma was distributed in the lamina propria and between epithelial cells (colloidal gold). The epithelial surface structure (scanning electron microscopy) appeared intact. Staining with nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase suggested that epithelial basal may contain nitric oxide synthases. We suggest that endogenously released nitric oxide from epithelial or other superficial cells tonically suppresses the macromolecular permeability of the subepithelial microcirculation.

Animals↗

PubMed1994

Growth of the parathyroid glands in omeprazole-treated chickens.

BACKGROUND: Omeprazole, a long-acting inhibitor of gastric acid secretion, is able to increase the circulating concentrations of gastrin. Daily treatment with high doses of omeprazole cause sustained hypergastrinemia. Long-standing hypergastrinemia can be expected to exert numerous effects in the body. For instance, gastrin has been proposed to promote growth in the digestive tract and pancreas. The present study is concerned with the effect of omeprazole on parathyroid glands in the chicken. METHODS: Chickens were treated with omeprazole (400 mumol/kg/day) in methylcellulose (2.5 ml/kg) for 5 or 10 weeks. Controls received vehicle. Blood calcium and serum gastrin concentrations were studied. The weight gain of the animals and of various organs (proventriculus, antrum, thyroids, parathyroids, ultimobranchial glands, and femur) were determined. The DNA content and the size of the parathyroid chief cells were also determined. RESULTS: Omeprazole reduced the body weight gain while greatly increasing the weight of the proventriculus and the parathyroid glands. The weight and density of the femur were reduced. The circulating concentrations of calcium were unaffected. The DNA content of the parathyroid glands was increased, and morphometric analysis of the parathyroid chief cells showed an increased cell size. Thus, the increased parathyroid gland weight seems to reflect both hypertrophy and hyperplasia. There was a slight increase in the weight of the ultimobranchial glands (expressed per kilogram body weight). The weight of the thyroids was unaffected (expressed in relation to body weight). CONCLUSIONS: The results indicate that omeprazole treatment in chickens leads not only to trophic effects in the acid-producing gastric mucosa (probably because of the ensuing hypergastrinemia), as reported earlier, but also to growth of the parathyroid glands (both hypertrophy and hyperplasia) and to bone loss without affecting blood calcium values. The mechanism behind these effects remains unknown.

Animals↗

PubMed1993

Helospectin/helodermin-like peptides in guinea pig lung: distribution and dilatory effects.

The lower airways of guinea pigs were analysed for helospectin and helodermin using immunocytochemistry. A moderate supply of helospectin/helodermin-like immunoreactive nerve fibers and few nerve fibers displaying helodermin immunoreactivity was seen in the smooth muscle, around seromucous glands and small blood vessels in the trachea and around bronchi and pulmonary blood vessels. Helospectin I-, helospectin II- and helodermin-induced suppression of smooth muscle responses were analysed using isolated circular segments of trachea and pulmonary arteries of guinea pigs. In both airways and arteries the peptides caused a concentration-dependent relaxation of precontracted segments. The maximal relaxant activity observed was more pronounced in the airways than in the arteries. The effects of the helospectins and helodermin were compared to those of vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), pituitary adenylate cyclase activating peptide (PACAP) and acetylcholine (ACh). All peptides, with the exception of PACAP, caused a total or nearly total relaxation of the precontracted tracheal segments. In the trachea PACAP was significantly more potent than the other five peptides whereas only small potency differences were seen in the pulmonary artery. The relaxant responses to helospectin I, helospectin II and helodermin in the trachea and the intrapulmonary arteries were unaffected by pretreatment with atropine, prazosin, yohimbine, propranolol, mepyramine and cimetidine. Conceivably, nerve fibers containing helospectin and helodermin may play a role in the regulation of airway resistance and in the regulation of local pulmonary blood flow.

Acetylcholine↗

PubMed1993

Peptide YY in the mammalian pancreas: immunocytochemical localization and immunochemical characterization.

Peptide YY (PYY) was demonstrated by immunochemical and/or immunocytochemical methods in endocrine cells in the pancreas of adult mice, rats, guinea-pigs, cats, dogs, pigs and cows. In the pancreas of mouse and rat, immunoreactive PYY was observed in a major subpopulation of the glucagon cells (splenic lobe of the pancreas); immunoreactive PYY also occurred in a subpopulation of the pancreatic polypeptide (PP) cells (duodenal lobe), and in a few extra-insular endocrine cells dispersed throughout the pancreatic parenchyma. In the pancreas of cat, dog and pig immunoreactive PYY was found to coexist with PP, but not with glucagon. Radioimmunoassay (RIA) revealed PYY-like material in extracts of pancreas (and colon) of all the species examined. The highest concentrations were found in the pancreas of cat and mouse; moderate amounts were found in the rat and only small amounts were detected in guinea-pig and pig. The concentrations in the pancreas were uniformly much lower than those in the colon. Analysis by high performance liquid chromatography (HPLC) showed that the PYY-immunoreactive material from pancreas (and rat colon) had an elution profile very similar to that of synthetic PYY, and distinct from that of PP and neuropeptide Y.

Amino Acid Sequence↗