Buccal Glands Research Articles

Cysteine-rich buccal gland protein suppressed the proliferation, migration and invasion of hela cells through akt pathway.

Cysteine-rich buccal gland protein (CRBGP) as a member of cysteine-rich secretory proteins (CRISPs) superfamily was isolated from the buccal glands of Lampetra japonica, the blood suckers in the marine. Previous studies showed CRBGP could suppress angiogenesis probably due to its ion channel blocking activity. Whether CRBGP could also affect the activity of tumor cells has not been reported yet. In this study, CRBGP suppressed the proliferation of Hela cells with an IC50 of 6.7 μM by inducing apoptosis. Both microscopic observation and Western blot indicated that CRBGP was able to induce the nuclei shrinking, downregulate the protein level of BCL2 and caspase 3 as well as upregulate the level of BAX in Hela cells, suggested that CRBGP might induce apoptosis of Hela cells in a mitochondrial-dependent pathway. Furthermore, CRBGP could disturb F-actin organization, which would finally cause the Hela cells to lose their shape and to lessen their abilities on adhesion, migration and invasion. Finally, CRBGP was shown to reduce the phosphorylation level of Akt, which indicated that CRBGP might inhibit the proliferation and metastasis of Hela cells through Akt pathway. CRBGP, as a voltage-gated sodium channel blocker, also possesses the anti-tumor abilities which provided information on the effects and action manner of the other CRISPs. © 2017 IUBMB Life, 69(11):856-866, 2017.

Molecular and evolutionary perspectives of the renin-angiotensin system from lamprey

The recent advance and revision on the renin-angiotensin system in lamprey were summarized and we emphasized that presence of two types of angiotensins (Angs) in lamprey. Due to the parasitic nature on fish blood, teleost-type Angs were produced in their buccal gland and secreted into the lamphredin to evade the host immunorejection. A native lamprey angiotensinogen (AGT) was identified in genome and it retains serine-protease inhibitor activity for thrombin that regulates the blood coagulation pathway. The native lamprey angiotensin II (Lp-Ang II) is hypotensive instead of hypertensive, suggesting a functional divergence on cardiovascular regulation from the main vertebrate groups. The renin gene was absent from the lamprey genome so far, and the mutation on the renin-recognition site on lamprey AGT suggested that other proteases may have replaced the role of renin. Lp-Ang II was shown to bind to AT1 receptor and internalized, but the downstream signaling was still unknown. Molecular and phylogenetic evidence on invertebrate ACE-like proteins indicated that they were not homologous to those in vertebrates and could be acting on other native peptides. Although it was generally believed that the RAS was a well-conserved hormone system in vertebrates and invertebrates, revision by molecular data indicated that invertebrates lack homologous RAS components while lamprey possess an almost complete RAS. This suggests that the hormone cascade system was first evolved around cyclostome emergence and invertebrates could have taken up the RAS components from vertebrates through horizontal gene transfer.

RLj-RGD3 induces apoptosis via the mitochondrial-dependent pathway and inhibits adhesion, migration and invasion of human HeyA8 cells via FAK pathway

Ovarian carcinoma is a tumor derived from ovary, which brings relatively higher mortality rate among the fatal gynecological cancers. Recently, lots of studies have concentrated on the anti-tumor effects of Arg-Gly-Asp (RGD) motif containing peptides due to their integrin binding properties. In order to meet the criterion of genetic engineering drugs, a recombinant RGD toxin protein (rLj-RGD3) without a His-tag was cloned from the buccal glands of Lampetra japonica in the present study. After endotoxin removal, the His-tag removed rLj-RGD3 was shown to inhibit the proliferation of HeyA8 cells. According to the confocal microscope, flow cytometry and western blot analysis, rLj-RGD3 could trigger HeyA8 cells apoptosis by changing mitochondrial membrane potential, arrangement of F-actin, protein level of BCL2, BAX, caspase 3, and cleaved caspase 3, concentration of cytoplasmic calcium, as well as phosphorylation level of ERK/JNK/p38. Furthermore, rLj-RGD3 was also able to suppress the adhesion, migration, and invasion processes of HeyA8 cells by disturbing the organization of F-actin and reducing the level of p-FAK. In addition, rLj-RGD3 could inhibit the adhesion of HeyA8 cells to extracellular matrix proteins by competitively binding to integrins, indicated that rLj-RGD3 might act as an anti-tumor drug to treat ovarian carcinoma patients in the future.

Minor salivary glands function is decreased in hyposalivation-related diseases

ObjectivesThe aim of this cross-sectional study was to investigate the relationship between minor salivary gland (MSG) flow rates and oral dryness degrees in patients with xerostomia induced by primary Sjögren’s syndrome (pSS), IgG4-related sialadenitis (IgG4-RS), radiation therapy-induced dry mouth (RTDM), or Steven–Johnson syndrome (SJS). Design160 patients with pSS, IgG4-RS, RTDM, or SJS and their age- and sex-matched healthy control subjects were enrolled. The whole saliva flow rates and MSG flow rates were measured in four locations, including the upper labial, lower labial, buccal, and palatal mucosae. The degree of oral dryness was assessed in patient groups using the summated xerostomia inventory (SXI). ResultsThe flow rates of whole saliva and most MSGs in patient groups were significantly lower than the flow rates in healthy control groups (P<0.05). The mean relative percentage of decrease in saliva flow rates was smaller in MSGs than in whole saliva in patient groups (P<0.05), indicating that these disorders have less impact on MSGs. Among the four MSG locations (the upper labial, lower labial, buccal, and palatal), buccal glands showed the highest flow rates in patient groups (P<0.05). SXI scores were significantly higher in pSS and RTDM patients than in IgG4-RS and SJS patients (P<0.05). The degree of xerostomia varied among different patient groups (P<0.05) and there was no clear correlation between MSG flow rates and SXI scores (P>0.05). ConclusionsMSG function is significantly reduced in pSS, RTDM, IgG4-RS, and SJS patients, but this reduction is more pronounced in the major salivary glands.

Data for the inhibition effects of recombinant lamprey CRBGP on the tube formation of HUVECs and new blood vessel generation in CAM models.

In the present data article, lamprey cysteine-rich buccal gland protein (CRBGP) which belongs to cysteine-rich secretory proteins (CRISPs) family was recombinant and expressed in Rosetta blue cells. After identification, the recombinant protein was purified through affinity chromatograph. The inhibition effects of recombinant lamprey CRBGP (rL-CRBGP) on tube formation of human umbilical vein endothelial cells (HUVECs) and new blood vessel generation in chick chorioallantoic membrane (CAM) models were analyzed. This paper contains data related to research concurrently published in “Anti-angiogenic activities of CRBGP from buccal glands of lampreys (Lampetra japonica)” [1].

Magnetic resonance imaging anatomy of the feline salivary glands

The aim of the study was to define anatomical characteristics of feline salivary glands using magnetic resonance imaging (MRI) and to describe landmarks for their reliable identification. Heads of 37 adult cats without signs of diseased salivary glands on clinical examination or history were examined. In cats included in the prospective part of the study, the MRI study was completed within one hour after euthanasia (n=16). In the retrospective part, previously performed MRI studies were evaluated (n=21). The prospective part of the study included the following standardized sequences: T2-weighted (T2W) turbo spin echo (TSE), T2W fat-suppressed TSE and proton density weighted (PDW) TSE images in a transverse plane as well as T1-weighted (T1W) fast field echo (FFE) in the transverse, sagittal and dorsal planes. In the retrospective part, T2W TSE and T1W TSE transverse images pre- and post-contrast were analyzed. Initially, identification and delineation of the salivary glands from surrounding tissue was assessed. Anatomical structures of the head were then identified and defined as landmarks. The dimensions of the glands were measured on T2W TSE images and the signal intensity in relation to that of fat and muscle was described using all sequences. In total, 95.9% of the parotid glands and 100% of the mandibular glands could be visualized on T1W TSE and FFE images and on T2W TSE images. Additionally, 93.3% of the zygomatic glands were identified on T2W TSE sequences and 82.5% on T1W TSE and FFE images. The ventral buccal glands could be demarcated in some sequences (T2W TSE: 51.4%, T1W TSE and FFE: 18.9%). Anatomical landmarks facilitated gland identification. Comparing the size of the salivary glands of both groups revealed differences of up to 2mm. Both the large salivary glands (Glandula [Gl.]. parotis and Gl. mandibularis) and the small salivary glands (Gl. zygomatica and Gl. buccalis ventralis) of the cat can be reliably identified on MRI images.

Integrative Taxonomy of the Micrura alaskensis Coe, 1901 Species Complex (Nemertea: Heteronemertea), with Descriptions of a New Genus Maculaura gen. nov. and Four New Species from the NE Pacific.

Micrura alaskensis Coe, 1901 is a common intertidal heteronemertean known from eastern and northwest Pacific (Alaska to Ensenada, Mexico and Akkeshi, Japan, respectively). It is an emerging model system in developmental biology research. We present evidence from morphology of the adults, gametes, and sequences of cytochrome c oxidase subunit I and 16S rRNA genes that it is not one, but a complex of five, cryptic species. All five of these species co-occur at least in part of their geographic range (e.g. southern Oregon). Preliminary cross-hybridization experiments suggest that at least some of these species are reproductively isolated. The five species share characteristics of adult morphology (e.g. accessory buccal glands) and at least four are known to possess a unique larval morphotype--pilidium maculosum. We propose that these characters define a new genus, Maculaura gen. nov., which contains the following five species: Maculaura alaskensis comb. nov., Maculaura aquilonia sp. nov., Maculaura cerebrosa sp. nov., Maculaura oregonensis sp. nov., and Maculaura magna sp. nov. It is unclear which of the five species Coe originally encountered and described. We chose to retain the name "alaskensis" for the species that current researchers know as "Micrura alaskensis", although, presently, it is only known from Washington and Oregon, and has not been collected from Alaska. Maculaura aquilonia sp. nov. is the only member of the genus we have encountered in Alaska, and we show that it also occurs in the Sea of Okhotsk, Russia.

Anti-angiogenic activities of CRBGP from buccal glands of lampreys (Lampetra japonica).

Cysteine-rich secretory proteins (CRISPs), characterized by 16 conserved cysteines, are distributed in a wide range of organisms, such as secernenteas, amphibians, reptiles and mammals. In the previous studies, a novel CRISP family member (cysteine-rich buccal gland protein, CRBGP) was separated from the buccal gland of lampreys (Lampetra japonica, L.japonica). Lamprey CRBGP could not only suppress depolarization-induced contraction of rat tail arterial smooth muscle, but also block voltage-gated sodium channels (VGSCs). In the present study, the anti-angiogenic activities of lamprey CRBGP were investigated using endothelial cells and chick chorioallantoic membrane (CAM) models. Invitro assays, lamprey CRBGP is able to induce human umbilical vein endothelial cells (HUVECs) apoptosis by disturbing the calcium homeostasis and mitochondria functions. In addition, lamprey CRBGP could inhibit proliferation, adhesion, migration, invasion and tube formation of HUVECs by affecting the organization of F-actin and expression level of matrix metallo-proteinase 2 (MMP-2), matrix metallo-proteinase 9 (MMP-9) and vascular endothelial growth factor A (VEGFA) which are related to angiogenesis. Invivo assays, lamprey CRBGP could suppress the blood vessel formation in CAM models. Therefore, lamprey CRBGP is an important protein present in the buccal gland of lampreys and might help lampreys suppress the contraction of blood vessels, nociceptive responses and wound healing of host fishes during their feeding time. In addition, lamprey CRBGP might have the potential to act as an effective anti-angiogenic factor for the treatment of abnormal angiogenesis induced diseases.

Identification and characterization of aldehyde dehydrogenase 9 from Lampetra japonica and its protective role against cytotoxicity.

Aldehyde dehydrogenases (ALDHs), which oxidize aldehyde to corresponding acids, play a major role in the detoxification of various endogenous and exogenous aldehydes. In this study, we cloned and characterized ALDH9 (designated LjALDH9) from Arctic lamprey Lampetra japonica. The open reading frame of LjALDH9 was 1566 bp, encoding 521 amino acids with a predicted molecular mass of 55.68 kDa. LjALDH9 protein had a signal peptide and Aldedh domain with the active site Cys315. In addition, LjALDH9 shares high sequence homology with ALDH9 of jawed vertebrates. Real-time quantitative PCR revealed that LjALDH9 was highly expressed in the buccal gland. A reactive LjALDH9 protein was obtained by prokaryotic expression, two-step-denaturing and refolding and affinity purification. During enzyme activity analysis of recombinant LjALDH9, we found that the most suitable reaction conditions were pH7.0, 16-23 °C and Mn(2+) as the activator. Our study provides theoretical proof that LjALDH9 plays an important role in the parasitic life phase of lamprey.

頰部に発生した小唾液腺由来多形腺腫の1症例

頰部に発生した小唾液腺由来多形腺腫の1症例

Characteristics of the saliva flow rates of minor salivary glands in healthy people

ObjectivesTo investigate the normal range and characteristics of saliva secretion in the minor salivary glands (MSGs). DesignThe flow rates of MSGs were measured in 4 anatomical locations of oral mucosa, and the relationship between MSG flow rates and whole saliva flow rates were assessed in 300 healthy subjects stratified by age and sex. An additional 30 young females were further evaluated for flow symmetry, effects of stimulation, circadian effects in MSGs, and the relationship with the flow rates of major salivary glands. Results(1) The mean saliva flow rates were 2.10±0.66 (lower labial glands), 2.14±0.62 (upper labial glands), 2.88±0.72 (buccal glands) and 2.15±0.51 (palatal glands) μl/min/cm2, respectively. The flow rate of buccal glands was significantly higher than the rates of SMGs in other locations (P<0.01). (2) 5-year-old children had the lowest MSG flow rates (P<0.0001) while the 10–14-year-old group had the highest (P<0.001). (3) MSG flow rates were independent of sex (P>0.05), right vs. left (P>0.05), and citric acid (2.5%) stimulation (P>0.05). (4) Only labial MSG displayed a significant secretory circadian rhythm with the highest rate in the evening (P<0.05). (5) A weak correlation was found between the flow rate of palatal glands and that of unstimulated whole saliva (r=0.195, P=0.007). ConclusionsOur findings provide a reference for functional evaluation of MSGs and for donor site selection of MSG transplantation for treatment of severe dry eye syndrome.

Identification and characterization of a cathepsin D homologue from lampreys (Lampetra japonica)

Cathepsin D (EC 3.4.23.5) is a lysosomal aspartic proteinase of the pepsin superfamily which participates in various digestive processes within the cell. In the present study, the full length cDNA of a novel cathepsin D homologue was cloned from the buccal glands of lampreys (Lampetra japonica) for the first time, including a 124-bp 5′ terminal untranslated region (5′-UTR), a 1194-bp open reading frame encoding 397 amino acids, and a 472-bp 3′-UTR. Lamprey cathepsin D is composed of a signal peptide (Met 1-Ala 20), a propeptide domain (Leu 21-Ala 48) and a mature domain (Glu 76-Val 397), and has a conserved bilobal structure. Cathepsin D was widely distributed in the buccal glands, immune bodies, hearts, intestines, kidneys, livers, and gills of lampreys. After challenging with Escherichia coli or Staphylococcus aureus, the expression level of lamprey cathepsin D in the buccal gland was 8.5-fold or 6.5-fold higher than that in the PBS group. In addition, lamprey cathepsin D stimulated with Escherichia coli was also up-regulated in the hearts, kidneys, and intestines. As for the Staphylococcus aureus challenged group, the expression level of lamprey cathepsin D was found increased in the intestines. The above results revealed that lamprey cathepsin D may play key roles in immune response to exogenous pathogen and could serve as a potential antibacterial agent in the near future. In addition, lamprey cathepsin D was subcloned into pcDNA 3.1 vector and expressed in the human embryonic kidney 293 cells. The recombinant lamprey cathepsin D could degrade hemoglobin, fibrinogen, and serum albumin which are the major components in the blood, suggested that lamprey cathepsin D may also act as a digestive enzyme during the adaptation to a blood-feeding lifestyle.

Pleomorphic Adenoma of Buccal Salivary Gland: A Case Report

The majority of minor salivary gland tumors are malignant. Of the benign tumors, pleomorphic adenomas are most common. The cheeks, lips, and gingiva are rarely sites of occurrence. A case of pleomorphic adenoma of the buccal salivary gland is presented here in 34 year old male patient, who was diagnosed as a pleomorphic adenoma of the minor salivary gland in the upper buccal vestibule.The tumor was a well circumscribed, firm mass, about 1.5cm in diameter, nontender & mobile in nature. Complete excision was performed and the HPR showed pleomorphic adenoma.

Low concentrations of the recombinant toxin protein rLj-RGD3 suppress TNF-&amp;alpha;-induced human renal carcinoma cell invasion

A hallmark of renal cell carcinoma (RCC) invasion is the degradation of the extracellular matrix (ECM) by the local production of gelatinase enzymes. Matrix metalloproteinase-9 (MMP-9)-induced cancer cell invasion is one of the pivotal steps in cancer metastasis. It has been reported that tumor necrosis factor-α (TNF-α), a regulator of MMP-9, can induce invasion in human renal carcinoma cells. Previous work in our laboratory has shown that rLj-RGD3, a recombinant RGD (Arg-Gly-Asp)-toxin protein from the buccal gland secretion of Lampetra japonica, possesses anti-tumor activity. In this study, we demonstrated that rLj-RGD3 suppressed TNF-α-induced MMP-9 secretion in 786-0 cells (human renal carcinoma cells). To investigate the regulatory effect of rLj-RGD3 on TNF-α-induced MMP-9 secretion, we pre-treated cells with rLj-RGD3. Interestingly, rLj-RGD3 had no significant effect on the constitutive secretion of MMPs. However, low concentrations of rLj-RGD3 decreased TNF-α-induced MMP-9 secretion. Functional studies revealed that rLj-RGD3 induced apoptosis and significantly inhibited the proliferation, migration, and invasion of 786-0 cells. Furthermore, the actin architecture in cells pre-treated with rLj-RGD3 was aggregated and disorganized. Our findings suggest that rLj-RGD3 may be used as a potential drug in renal cancer therapy.

Identification of l-3-hydroxykynurenine O-sulfate in the buccal gland secretion of the parasitic lamprey, Lethenteron japonicum

Parasitic lampreys are known to secrete proteins having anticoagulant and vasodilator activities from the buccal glands during feeding on their host's blood. However, small molecules in the secretion have never been explored in detail. We examined the secretion of Japanese liver lamprey (Lethenteron japonicum) for small molecules and found an intensely fluorescent substance upon gel filtration. After purification by anion-exchange chromatography and reversed-phase HPLC, structure of the compound was determined to be L-3-hydroxykynurenine O-sulfate by NMR- and UV-spectrometry, complemented with enzymatic and chemical degradation. In vertebrates, the sulfate ester of 3-hydroxykynurenine is a compound that has been regarded as a urinary metabolite of tryptophan but not reported from normal tissues to date. Although the function of this molecule in the buccal glands remains to be elucidated, it is remarkable that the same substance was described in 1960s from two species of blood-sucking insects, Rhodnius prolixus and Triatoma infestans, suggesting its potential role in blood-feeding.

Effects of the recombinant toxin protein rLj-RGD3 in multidrug-resistant human breast carcinoma cells

We have previously reported that Lj-RGD3, a novel RGD-toxin protein, was isolated from the buccal gland of Lampetra japonica. The recombinant protein rLj-RGD3 has anti-invasive and anti-adhesive activity in tumor cells (HeLa cells) and endothelial cells (ECV304 cells) in vitro, and inhibits αvβ3, αvβ5, and β1 integrin-mediated adhesion. In this study, we investigated the bioactivity of rLj-RGD3 in the drug-resistant MCF-7/Adr breast carcinoma cell line and drug-sensitive parental line MCF-7, and found that rLj-RGD3 inhibited the growth of both cell lines. Biological function studies revealed that rLj-RGD3 could induce the apoptosis in MCF-7/Adr, which was more prevalent than that in the drug-sensitive parental line MCF-7. In addition, rLj-RGD3 inhibited the adhesion of MCF-7/Adr cells to fibronectin. Furthermore, rLj-RGD3 prevented invasion of MCF-7/Adr cells through an artificial matrigel basement membrane. In summary, rLj-RGD3 may be used as a potential drug in multidrug-resistant breast cancer therapy.

Morphologic diversity of the minor salivary glands of the rat: fertile ground for studies in gene function and proteomics

In this article the locations and histologic and ultrastructural features of all of the minor salivary glands of the rat are presented; similarities and differences among them are highlighted. These glands are almost as diverse morphologically as the major salivary glands of the rat. The acini of von Ebner's glands are serous; those of the anterior and posterior buccal glands and minor sublingual glands are mucous; and those of the glossopalatal, palatal, and Weber's glands are mucous with serous demilunes. The anterior buccal, minor sublingual and von Ebner's glands have striated and stratified columnar ducts, while only the minor sublingual and von Ebner's glands have intercalated ducts. The glossopalatal, palatal, posterior buccal and Weber's glands have none of these ducts; the tubulo-acini drain abruptly into short terminal ducts composed of stratified squamous epithelium. All of the mucous acini react with an antibody to a mucin (Muc19) of the rat major sublingual gland, but in some of the glands the reaction varies in intensity among the acinar cells. Ultrastructurally, the mucous secretory granules of the anterior buccal, glossopalatal, palatal and Weber's glands are biphasic, while those of the minor sublingual and posterior buccal glands are monophasic. Although there is a considerable body of literature concerning the development, innervation, physiology and proteomics of von Ebner's glands, investigation of the other minor salivary glands of the rat ranges from modest to nearly nonexistent.

Mucosa-associated lymphatic tissue lymphoma of the lower lip in a child☆,☆☆

Mucosa-associated lymphatic tissue lymphoma of the lip in a child is a very rare clinical entity whose cause is poorly understood. We describe an 11-year-old boy who presented with a 5-month history of an asymptomatic nodule on the lower lip with the clinical appearance of a benign mucocele. After surgical excision of the lower lip lesion, lymphocyte phenotypic analysis and histologic examination of the specimen disclosed an extranodal marginal zone B-cell lymphoma of mucosa-associated lymphatic tissue type of the buccal minor salivary glands. Mucosa-associated lymphatic tissue lymphoma of the lip may clinically resemble a large mucocele. To prevent a delayed detection of lip mucosa-associated lymphatic tissue lymphoma, an incisional biopsy of large mucous cysts of the oral mucosa before marsupialization is recommended.

MR Anatomy of Salivary Glands in the Dog

This retrospective analysis documented the magnetic resonance imaging (MRI) appearance of normal salivary glands based on 101 studies in dogs with no detectable disease in the splanchnocranium. Surface, signal intensity, homogeneity, structure, symmetry and the relationship of glands to surrounding tissues were noted, and gland topography was assessed with E12 plastinated embedded sections. Signal intensity of salivary glands was isointense (7-40%) to hyperintense (60-90%) to muscle tissue on T1- and hyperintense on T2-weighted images. Salivary glands had an increased T1 signal after contrast medium was applied. Salivary gland structure appeared homogeneous in mandibular and major sublingual glands and heterogeneous in zygomatic and parotid glands. Consistent landmarks were the external auditory canal for parotid glands, the digastric muscle for mandibular and major sublingual glands, and the pterygopalatine fossa for zygomatic glands. The minor sublingual and ventral buccal glands could not be localized with low-field MRI.

The presence of teleost-type angiotensin components in lamprey buccal gland suggests a role in endocrine mimicry

Previous characterization of a native lamprey angiotensin II (LpAng II) that possesses a different sequence and function than teleost-type angiotensin II (Ang II) has raised a question as to the role of teleost-type angiotensin peptides in lampreys. In this study, teleost-type angiotensin like-peptides were identified in the buccal gland of lampreys by immunoassays and immunohistochemistry. The possible sources of angiotensin like-peptides were investigated in lampreys by manipulating their choice of host and food. Ang II immunoreactivity (irAng II) was detected in the buccal gland and plasma of feeding phase sea lampreys exposed to Atlantic cod, but was mostly absent in fasting lamprey. Qualitatively, the HPLC profiles of irAng II observed in the plasma, when present, were highly similar to those in buccal gland, implying that the buccal gland could be a source of plasma Ang II. Japanese lampreys force-fed with dogfish blood had significantly elevated concentrations of irAng II in their buccal glands when compared to unfed individuals, suggesting that feeding stimuli may have enhanced buccal gland activity. Teleost-type Ang II-containing proteins, other than angiotensinogen, are present in the buccal gland as trypsinization generated Ang II in vitro, and the HPLC profile of these irAng II was highly comparable to those naturally present in the buccal gland. [Asn1, Val5, Thr9]-Ang I that was identified in the buccal gland of Japanese lampreys has the same amino acid sequence to those previously isolated from the incubation of plasma and kidney extract, providing an alternative explanation for the previous isolation of teleost-type Ang I in lampreys. irAng I and irAng II were localized in the granule-like structures in the apical region of the secretory epithelia, suggesting that these peptides may be active components of lamphredin. The teleost-type angiotensin peptides in the buccal gland secretion suggested that these host-specific peptides could be part of the endocrine mimicry strategy used by lampreys to evade host immune responses and reduce immune-rejection.