Biomedical subjects

F Sundler

Publications and source records attributed to F Sundler.

At least 271 records · Page 15Linked to original sources

PubMed1989

Gastrin releases a blood calcium-lowering peptide from the acid-producing part of the rat stomach.

Gastrin-17 induces hypocalcemia in the rat without stimulating calcitonin release. The gastrin-induced hypocalcemia persisted after thyroparathyroidectomy or parathyroidectomy. In contrast, gastrectomy or extirpation of the acid-producing part of the stomach prevented the hypocalcemic effect, suggesting the involvement of the proximal stomach in the gastrin-evoked lowering of blood calcium. The drop in blood calcium upon injection of gastrin-17 did not reflect a loss of calcium via the gastric juice or via the urine. Extracts of the acid-producing mucosa of the rat stomach had a hypocalcemic effect. The extracts were purified by gel chromatography and reversed-phase high-performance liquid chromatography. Digestion with leucine aminopeptidase destroyed the hypocalcemic activity, while trypsin had no effect, suggesting a peptide (or peptides) with an unprotected NH2 terminus and without basic amino acid residues (or with protected basic amino acids). Both gastrin-17 and the mucosal extract stimulated the uptake of 45Ca into bone (radius and sternum). Gastrin-17 was without effect in rats that had undergone gastrectomy, while the mucosal extract was equally effective in gastrectomized and unoperated rats. We suggest that the effects of gastrin-17 on blood calcium and on calcium transfer into bone are indirect and that gastrin-17 stimulates the release of a peptide hormone, tentatively named gastrocalcin, from the acid-producing mucosa of the stomach. Gastrocalcin stimulates the uptake of 45Ca into bone, thereby causing hypocalcemia.

Animals↗

PubMed1989

Effects of capsaicin pretreatment on neuropeptides and salivary secretion of rat parotid glands.

1. 'Atropine-resistant' secretion of saliva in response to parasympathetic stimulation may reflect antidromic activation of sensory nerve fibres. In this investigation, the effect of pretreatment in the rat with capsaicin (total dose of 125 mg kg-1, s.c.), was determined. 2. In the parotid glands substance P (SP)/calcitonin gene-related peptide (CGRP)-containing nerve fibres around ducts and blood vessels disappeared after capsaicin, while periacinar SP-containing fibres (devoid of CGRP) and CGRP-containing fibres (devoid of SP) remained. Vasoactive intestinal peptide (VIP)-containing nerve fibres seemed to be unaffected. The parotid content of SP and CGRP was reduced by 11 and 36% respectively, while that of VIP remained unchanged. 3. The weights of the parotid glands and their sensitivity to the secretagogues methacholine and SP, injected intravenously, were unchanged as was the response to stimulation of the auriculo-temporal nerve in the presence and absence of atropine. 4. In contrast to capsaicin pretreatment, parasympathetic denervation of the parotid gland reduced the weight of the gland and produced an increase in the response to methacholine and SP. 5. For comparison, the effectiveness of the capsaicin treatment on neuropeptide content was determined in the urinary bladder. The bladder of capsaicin-pretreated rats increased in weight (21%) and in VIP content (31%), while the content of SP and CGRP was reduced by 86 and 94%, respectively. SP- and CGRP-containing nerve fibres were virtually eliminated, while VIP-containing nerve fibres seemed unaffected. 6. In conclusion, antidromic activation of primary afferent (capsaicin-sensitive) C-fibres does not contribute significantly to the 'atropine-resistant' secretory response of the parotid gland to stimulation of the parasympathetic nerve.

Animals↗

PubMed1989

Immunoreactive delta sleep-inducing peptide secretion from mouse dissociated, anterior pituitary cells: regulation by corticotropin-releasing factor and arginine vasopressin.

Immunoreactive delta sleep-inducing peptide (IR-DSIP) has previously been localized to the ACTH/MSH cells of the human and porcine pituitary gland. In the present report, the distribution of IR-DSIP in the mouse pituitary gland was examined by immunocytochemistry. In this species, IR-DSIP was found to be co-localized with thyroid-stimulating hormone (TSH) in anterior pituitary thyrotrophs and was also present in nerve fibers in the posterior and intermediate lobes. The effect of synthetic DSIP on IR-ACTH release from dissociated mouse anterior pituitary cells was also studied. DSIP (greater than or equal to 10(-9) M) inhibited both basal and CRF-induced IR-ACTH release from these cells. In addition, the effect of synthetic rat corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) on IR-DSIP secretion was investigated. CRF and AVP at concentrations of 10(-11)-10(-7)M inhibited release of IR-DSIP from mouse anterior pituitary cells by 63%. When CRF and AVP (10(-10)-10(-7) M) were given concomitantly, the maximal inhibition of IR-DSIP release was observed at a concentration of 10(-8)M of CRF and AVP. However, these two peptides when given together showed no additive effect on IR-DSIP secretion. These findings suggest that during CRF induction of ACTH secretion from anterior pituitary corticotrophs, CRF may also act simultaneously to inhibit DSIP secretion from the thyrotrophs.

Adrenocorticotropic Hormone↗

PubMed1989

Projections of enteric peptide-containing neurons in the rat.

In order to understand better the neuronal circuitry involved in the regulation of gut functions, we have studied the distribution and projections of those enteric neurons in the rat intestines that contain vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), galanin, substance P (SP), calcitonin gene-related peptide (CGRP), gastrin releasing peptide (GRP), somatostatin and enkephalin. The origin of the peptide-containing nerve fibers was examined by immunocytochemistry after extrinsic denervation. Most of them were found to be intramural in origin, each population displaying its own characteristic topographic distribution. The projections of each neuronal population were studied immunocytochemically by examining the subsequent axonal degeneration after local severing of nervous pathways. This study revealed that myenteric neurons issue predominantly descending projections to other myenteric ganglia and to the muscle layers. Submucous neurons project to other submucous ganglia and to the mucosa and submucosa. Most of these neurons issue both ascending and descending projections. The projection distances varied considerably between the different neuronal populations, the majority being in the range of 4-10 mm. Myenteric GRP and galanin neurons in the small intestine issued the longest projections, 20 and 15 mm, respectively. The shortest projections were those issued from myenteric VIP/NPY neurons and submucosal galanin and GRP neurons in the small intestine and from submucosal VIP neurons in the large intestine (2 mm in length). On the whole our results on the projections of enteric neurons in the rat agree with observations in the guinea pig and dog. However, there are species differences that remain to be explained.

Animals↗

PubMed1989

The neuroendocrine system of the gut.

The digestive tract is the richest source of regulatory peptides outside the brain. Such peptides occur all along the gut in the neuroendocrine system which is composed of endocrine/paracrine cells disseminated in the epithelium and of intrinsic neurons that form continuous ganglionic chains in the submucosa and in the muscle layer. Some endocrine/paracrine cells, particularly in the stomach, still have not been associated with an identified regulatory peptide implying that our present knowledge is far from complete. The intracellular processing of regulatory peptide precursors involves multi-step proteolytic cleavage generating several fragments. In many instances more than one biologically active peptide is generated from one and the same precursor. In addition, certain endocrine/paracrine cells and neurons have been found to produce more than one peptide precursor and some are known to harbour 'classical' neurotransmitters, such as 5-hydroxytryptamine, histamine and GABA as well as regulatory peptides. Key questions for the future are the functional significance of the coexistence of multiple messengers within the same cells and the details of how the endocrine/paracrine cells and the neurons in the gut interact.

Animals↗

PubMed1989

Innervation of the thyroid. A study of the rat using retrograde tracing and immunocytochemistry.

The distribution and origin of the nerve fibers innervating the rat thyroid were studied by immunocytochemistry in experiments involving retrograde tracing and denervations. Nerve fibers containing noradrenaline (NA), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), galanin (GAL), substance P (SP), and calcitonin gene-related peptide (CGRP) occurred around blood vessels and follicles. Many of these transmitter candidates coexisted with each other in different combinations in different subpopulations of neurones. Injection of the retrograde tracer True Blue into the thyroid gland labelled cell bodies in the thyroid ganglion, the laryngeal ganglion, the superior cervical ganglion, the jugular-nodose ganglionic complex, the dorsal root ganglia (C2-C5) and the trigeminal ganglion. Judging from the number of labelled nerve cell bodies, the superior cervical ganglion and the thyroid ganglion contribute most to the thyroid innervation, while the laryngeal ganglion and the trigeminal ganglion contribute least. Results from denervation and tracer experiments indicate that all NA-containing and the majority of NPY-containing nerve fibers in the thyroid derive from the superior cervical ganglion. All VIP- and a minor population of NPY- and GAL-containing fibers in the thyroid gland originate in the thyroid ganglion. Nerve fibers containing GAL, SP and/or CGRP emanate from the jugular, cervical dorsal root and/or trigeminal ganglia. Together the findings indicate that several ganglia project to the thyroid and that many neuropeptides may be involved in the control of thyroid activity.

Animals↗

PubMed1989

Proliferation of enterochromaffinlike cells in omeprazole-treated hypergastrinemic rats.

The effect of high doses of omeprazole on the proliferation of the histamine-storing endocrine cells in the oxyntic mucosa, the so-called enterochromaffinlike (ECL) cells, was studied in the rat stomach by combining immunocytochemical staining for histamine with autoradiography after in vivo labeling with [3H]thymidine. Under basal conditions the ECL cells divided very slowly. A progressive increase in the ECL cell labeling index was observed from the second day of omeprazole treatment. The ECL cell density increased progressively from the ninth day of treatment. The plasma gastrin levels were doubled and the labeling index of the cells in the progenitor cell zone was significantly increased. Our data indicate that the omeprazole-evoked ECL cell hyperplasia is a result of accelerated self-replication. The positive correlation between the plasma gastrin concentration and the ECL cell labeling index is compatible with a causal relationship between circulating gastrin levels and increased ECL cell density.

Animals↗

PubMed1989

Peptide YY: intrapancreatic localization and effects on insulin and glucagon secretion in the mouse.

We studied the intrapancreatic localization of peptide YY (PYY) and the effects of PYY on insulin and glucagon secretion in the mouse. Immunofluorescence staining of mouse pancreatic tissue showed that PYY occurred within islet cells. These cells were located preferentially at the periphery of the islets. Sequential and simultaneous double immunostaining revealed that most PYY cells also displayed glucagon immunoreactivity; some PYY cells contained immunoreactive pancreatic polypeptide (PP). At the electromicroscopic level, PYY immunoreactivity was demonstrated within the secretory granules of both glucagon cells and of a small granular cell type, which showed structural similarities to PP cells. In in vivo experiments, PYY at dose levels between 0.53 and 8.5 nmol/kg had no influence on basal plasma levels of insulin, glucagon, or glucose. In contrast, insulin secretion stimulated by glucose or the cholinergic agonist carbachol was inhibited by PYY (by 33 and 26%, respectively, at 4.25 nmol/kg). Similarly, carbachol-induced glucagon secretion was inhibited by PYY (by 47% at 4.25 nmol/kg). We conclude that PYY occurs in islet cells of the mouse pancreas, most of which are glucagon cells, and that PYY inhibits stimulated insulin and glucagon secretion in vivo in the mouse.

Animals↗

PubMed1988

Sensory innervation of the ear drum and middle-ear mucosa: retrograde tracing and immunocytochemistry.

The distribution and origin of nerve fibers of presumed sensory nature in the ear drum and middle-ear mucosa of the rat were studied by a retrograde tracing technique in combination with immunocytochemistry. Application of True Blue (TB) on the ear drum or on the middle-ear mucosa labeled nerve cell bodies in the jugular, trigeminal, geniculate and cervical dorsal root ganglia (C2-C4). Judging from the number of TB-labeled nerve cell bodies the jugular and trigeminal ganglia contributed the major component to the sensory innervation of the ear drum and the middle-ear mucosa, while the contribution from the geniculate and cervical dorsal root ganglia was relatively minor. The majority of the TB-labeled nerve cell bodies contained calcitonin gene-related peptide (CGRP), whereas minor populations stored substance P (SP) and neurokinin A (NKA). Nerve fibers containing SP, NKA and CGRP were moderate in number in the middle-ear mucosa and few in the ear drum. Double immunostaining revealed that SP invariably coexisted with NKA in nerve cell bodies in the ganglia examined. The SP/NKA-containing nerve cell bodies constituted a subpopulation of those storing CGRP. The findings indicate that several ganglia project to the ear drum and middle-ear mucosa and that many neuropeptides are involved in the mediation of middle-ear sensitivity.

Afferent Pathways↗

PubMed1988

Histamine-like immunoreactivity in photoreceptors of the compound eyes and ocelli of the flies Calliphora erythrocephala and Musca domestica.

Antibodies to histamine were used for immunocytochemical studies of the visual system in the flies Calliphora erythrocephala and Musca domestica. Specific immunolabeling of photoreceptors was found both in the compound eyes and ocelli of both species. In the compound eyes histamine-like immunoreactivity (HA-IR) was found in all the short visual fibers (photoreceptors R1-6) and one type of long visual fiber (photoreceptor R8). In addition, the ocellar photoreceptors also show HA-IR. In view of earlier biochemical and pharmacological/physiological findings by Elias and Evans (1983) and Hardie (1987) it thus seems likely that histamine is a neurotransmitter in insect photoreceptors. Interestingly, the second type of long visual fiber (photoreceptor R7) has recently been found to be GABA-immunoreactive (Datum et al. 1986). The two types of long visual fibers may hence use different transmitters which act on different receptors of the postsynaptic neurons in the second visual neuropil, the medulla. In addition to the photoreceptors in the retina and ocelli, we found processes of HA-IR neurons in one of the optic lobe neuropils, the lobula. This finding indicates that histamine may also be a transmitter in certain interneurons in the visual system.

Animals↗

PubMed1988

Hypergastrinaemia induced by acid blockade evokes enterochromaffin-like (ECL) cell hyperplasia in chicken, hamster and guinea-pig stomach.

Treatment of chickens, hamsters and guinea-pigs with large doses of the long-acting antisecretory agent omeprazole for 10 weeks resulted in elevated serum gastrin levels and in increased stomach weight and mass of oxyntic mucosa. Also the antral gastrin cell density was increased. Another striking effect was the hyperplasia of the histamine-producing enterochromaffin-like (ECL) cells - a prominent endocrine cell population with unknown function-in the oxyntic mucosa. Accordingly, the gastric mucosal histamine concentration and rate of histamine formation were increased in all three species. The results suggest that marked and long-lasting suppression of acid secretion leads to elevated serum gastrin levels and diffuse ECL cell hyperplasia not only in the rat, as previously seen, but also in the chicken, hamster and guinea-pig; this hyperplasia is associated with accelerated histamine formation in all three species. The following sequence of events is suggested to occur in mammalian as well as submammalian vertebrates: suppression of acid secretion - hypergastrinaemia - ECL cell hyperplasia.

Animals↗

PubMed1988

Neuropeptide Y and vasoactive intestinal peptide coexist in rat thyroid nerve fibers emanating from the thyroid ganglion.

Neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) occur in nerve fibers around blood vessels and between follicles in the thyroid gland of the mouse and rat. VIP-immunoreactive fibers are numerous, while NPY-immunoreactive fibers are fewer. Most of the latter fibers contain noradrenaline (NA) as well as NPY, while a subpopulation was found to contain VIP instead of NA. We have determined the origins of rat thyroid nerve fibers containing NPY, VIP or NPY/VIP by investigating 3 conceivable sources, i.e. the superior cervical ganglion, the nodose ganglion and the thyroid ganglion. Chemical sympathectomy or removal of the superior cervical ganglion did not affect the frequency of VIP-immunoreactive fibers but eliminated most of the NPY-immunoreactive fibers as well as all NA-containing nerve fibers (recognized by antibodies to dopamine-beta-hydroxylase). The NPY-immunoreactive fibers that remained after sympathectomy occurred around blood vessels and between follicles and contained VIP. Cervical vagotomy (removal of the nodose ganglion including the adjacent vagus) did not overtly affect the frequency of NPY/VIP-, VIP-, or NPY/NA-containing fibers in the thyroid. In contrast, extirpation of the thyroid ganglion, which is situated immediately outside the thyroid capsule, greatly reduced the number of VIP- and NPY/VIP-containing fibers in the rat thyroid. On the whole, the results of radioimmunoassay of NPY and VIP agreed well with the immunocytochemical findings. High performance liquid chromatography confirmed the identity of NPY and VIP. The present findings suggest the existence in the rat thyroid of one NPY-containing nerve fiber population that harbours NA and emanates from the superior cervical ganglion; one NPY-containing fiber population that is non-adrenergic, harbours VIP and originates in the thyroid ganglion; and a second VIP-containing fiber population that is devoid of NPY and appears to derive from the thyroid ganglion.

Animals↗

PubMed1988

Gastrin and the vagus interact in the trophic control of the rat oxyntic mucosa.

Gastrin is a trophic hormone for the stomach, and permanent reduction of circulating gastrin by antrectomy leads to atrophy of the oxyntic mucosa, including a reduced density of histamine-storing endocrine cells (so-called ECL cells). Recently, it was proposed that also the vagal nerve has a trophic influence on the stomach. The two vagal trunks innervate the anterior and posterior side of the gastric wall, respectively. This arrangement makes it possible to denervate one side of the stomach selectively. The objective of the present study was to examine the consequences of combined antrectomy and vagotomy (unilateral or bilateral). Male Sprague-Dawley rats were subjected to unilateral or bilateral subdiaphragmatic truncal vagotomy with or without antrectomy. Control rats were sham-operated. The rats were killed 8 weeks after the operation. Bilateral vagotomy raised the basal serum gastrin concentration (fasting level). The thickness of the oxyntic mucosa and the density of ECL cells were not significantly different from age-matched vagally intact controls. Unilateral vagotomy induced no change in the basal serum gastrin concentration, nor did it affect the mucosa on the intact side. On the denervated side, however, there was reduced mucosal thickness and a greatly reduced ECL cell density. With a combination of antrectomy and vagal denervation the decrease in ECL cell density was exaggerated compared to the effect of antrectomy or unilateral vagotomy alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

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. Cells displaying helodermin-like immunoreactivity were found in all tumours examined except one. On the whole the helodermin-immunoreactive cells had the same distribution as those storing calcitonin, suggesting coexistence of the two peptides in most of the tumour cells. Also normal human C-cells displayed helodermin immunoreactivity. The results suggest that a peptide chemically related to helodermin is a constituent of human medullary thyroid carcinoma cells as well as of normal C-cells.

Fluorescent Antibody Technique↗

PubMed1988

Immunocytochemical localization of galanin in the rat male and female genital tracts and motor effects in vitro.

Galanin, a recently discovered neuropeptide, was studied in the rat male and female reproductive tracts by immunocytochemistry and in vitro pharmacology. Nerve fibers containing galanin immunoreactivity were most abundant in the female paracervical tissue, where they surrounded non-immunoreactive ganglion cells. Galanin nerves were also found in the uterus and Fallopian tubes, as well as in the vas deferens. When tested in vitro galanin contracted the smooth muscle of both the uterine horn and cervix. Galanin also slightly potentiated the response to electrical field stimulation in preparations from the uterine cervix and vas deferens, but it had no effect on the seminal vesicle. Galanin-(1-10), an N-terminal residue of galanin, also contracted the uterine horn, though higher concentrations were required. The neurally induced contractions were not influenced by galanin-(1-10) in any of the smooth muscle preparations tested. The muscle receptors mediating the direct contractile effects in the uterine horn seem to require the N-terminus of galanin, while the neuromodulatory effects on the electrically induced contractile activity seem to need the C-terminal part or the whole galanin molecule. Galanin may thus function as a neuromediator in the rat male and female genital organs.

Animals↗

PubMed1988

Cholecystokinins but not gastrin-17 release calcitonin from thyroid C-cells in the rat.

Subcutaneous injections of gastrin-17, cholecystokinin-39, cholecystokinin-8 (sulfated and non-sulfated forms), cholecystokinin-4 or pentagastrin induced hypocalcemia in rats. The hypocalcemia was associated with calcitonin release for pentagastrin and the cholecystokinins but not for gastrin-17, even at very high doses. Permanent hypergastrinemia, induced by surgical removal of the acid-producing part of the stomach (fundectomy) or by treatment with high doses of omeprazole, a blocker of acid secretion, was not accompanied by elevated plasma calcitonin. Long-lasting hypergastrinemia is known to cause hyperplasia of gastrin-sensitive endocrine cells in the rat stomach while hypogastrinemia does the reverse. In antrectomized rats, having low serum gastrin, and in fundectomized rats, having high serum gastrin, the serum calcitonin concentration, the thyroid calcitonin content and the number of C-cells remained as in sham-operated controls two months after the operations. We conclude that neither exogenous nor endogenous gastrin stimulates calcitonin secretion in the rat and that long-standing hypo- or hypergastrinemia is without effect on the number of thyroid C-cells. Our results, however, do not exclude the possibility that the cholecystokinins might act as calcitonin secretagogues in the rat although such a role remains to be established.

Animals↗

PubMed1988

Hypergastrinaemia evoked by omeprazole stimulates growth of gastric mucosa but not of pancreas or intestines in hamster, guinea pig and chicken.

Treatment of chickens, hamsters and guinea-pigs with the long-acting anti-secretagogue omeprazole resulted in elevated levels of serum gastrin. The chickens received 400 mumol/kg by i.m. injection once daily, the hamsters and guinea-pigs received the same dose by the oral route once daily. In all 3 species omeprazole raised the intragastric pH to 4, measured 12-14 h after the administration of the drug. After 10 weeks of treatment, trophic changes were observed in the stomach of hamster and guinea pig and in the proventriculus of chicken. The trophic changes were manifested in a greatly increased stomach weight and gastric mucosal mass. There were no trophic effects outside the stomach (or proventriculus). The results are in agreement with previous observations in the rat and support the view that long-lasting sustained hypergastrinaemia causes trophic changes in the stomach but not in the pancreas or in the intestines.

Animals↗

PubMed1988

Calcitonin gene-related peptide in rat salivary glands: neuronal localization, depletion upon nerve stimulation, and effects on salivation in relation to substance P.

Calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibres occurred predominantly around blood vessels and large ducts and, to a minor extent, around acini and small ducts in the parotid, sublingual and submaxillary glands of the rat. Double immunostaining showed most of the CGRP-containing nerve fibres to contain substance P. However, the vast majority of substance P-immunoreactive periacinar nerve fibres in the parotid and submandibular glands lacked CGRP. After parasympathetic denervation of the parotid gland by section of the auriculotemporal nerve these periacinar substance P-immunoreactive nerve fibres disappeared almost completely, whereas the number of substance P/CGRP-immunoreactive nerve fibres seemed unchanged. After this operation the total amount of substance P in the parotid gland was reduced by about 90% as judged by radioimmunoassay; in denervation experiments the facial nerve was found to contribute to the residual substance P content. In contrast, the contribution of the auriculotemporal nerve to the CGRP content of the gland was small; the reduction in CGRP after section of the nerve was 20%. The facial nerve and the dorsal root nerves (C3 and C4) contributed to the CGRP content with about 50%. The source of the remaining 30% of the parotid gland CGRP is unknown. It is not the sympathetic nerve: sympathetic denervation resulted in a marked increase in CGRP, regardless of whether the auriculotemporal nerve was intact or not. Upon long-lasting electrical stimulation of the auriculotemporal nerve at a high frequency the parotid gland content of CGRP was gradually reduced, indicating depletion of this peptide in response to nerve stimulation. Intravenous injections of CGRP evoked no salivary flow; however, a release of amylase was revealed. Also, when CGRP was tested on isolated parotid gland lobules amylase was released into the medium. When, in vivo, CGRP was injected in combination with substance P, the substance P-evoked flow of parotid and submaxillary saliva was markedly enhanced. In addition, CGRP enhanced the in vivo secretory response to parasympathomimetics and to vasoactive intestinal peptide. The localization of CGRP-containing nerve fibres suggests that CGRP is involved in the regulation of secretion and blood flow of salivary glands. CGRP may interact positively with acetylcholine and certain nonclassical transmitters, and it may be involved (together with other neuropeptides) in the atropine-resistant parasympathetic secretion occurring in the glands under study.

Amylases↗