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Santillo A, Chieffi Baccari G, Minucci S, Falvo S, Venditti M, Di Matteo L. The Harderian gland: Endocrine function and hormonal control. Gen Comp Endocrinol 2020; 297:113548. [PMID: 32679156 DOI: 10.1016/j.ygcen.2020.113548] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 01/17/2023]
Abstract
The Harderian gland (HG) is an exocrine gland located within the eye socket in a variety of tetrapods. During the 1980s and 1990s the HG elicited great interest in the scientific community due to its morphological and functional complexity, and from a phylogenetic point of view. A comparative approach has contributed to a better understanding of its physiology. Whereas the chemical nature of its secretions (mucous, serous or lipids) varies between different groups of tetrapods, the lipids represent the more common component among different species. Indeed, besides being an accessory to lubricate the nictitating membrane, the lipids may have a pheromonal function. Porphyrins and melatonin secretion is a feature of the rodent HG. The porphyrins, being phototransducers, could modulate HG melatonin production. The melatonin synthesis suggests an involvement of the HG in the retinal-pineal axis. Finally, StAR protein and steroidogenic enzyme activities in the rat HG suggests that the gland contributes to steroid hormone synthesis. Over the past twenty years, much has become known on the hamster (Mesocricetus auratus) HG, unique among rodents in displaying a remarkable sexual dimorphism concerning the contents of porphyrins and melatonin. Mainly for this reason, the hamster HG has been used as a model to compare, under normal conditions, the physiological oxidative stress between females (strong) and males (moderate). Androgens are responsible for the sexual dimorphism in hamster and they are known to control the HG secretory activity in different species. Furthermore, HG is a target of pituitary, pineal and thyroid hormones. This review offers a comparative panorama of the endocrine activity of the HG as well as the hormonal control of its secretory activity, with a particular emphasis on the sex dimorphic aspects of the hamster HG.
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Affiliation(s)
- Alessandra Santillo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania 'Luigi Vanvitelli', Via Vivaldi, 43-81100 Caserta, Italy.
| | - Gabriella Chieffi Baccari
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania 'Luigi Vanvitelli', Via Vivaldi, 43-81100 Caserta, Italy
| | - Sergio Minucci
- Dipartimento di Medicina Sperimentale, Sez. Fisiologia Umana e Funzioni Biologiche Integrate, Università degli Studi della Campania 'Luigi Vanvitelli', via Santa Maria di Costantinopoli, 16-80138 Napoli, Italy
| | - Sara Falvo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania 'Luigi Vanvitelli', Via Vivaldi, 43-81100 Caserta, Italy
| | - Massimo Venditti
- Dipartimento di Medicina Sperimentale, Sez. Fisiologia Umana e Funzioni Biologiche Integrate, Università degli Studi della Campania 'Luigi Vanvitelli', via Santa Maria di Costantinopoli, 16-80138 Napoli, Italy
| | - Loredana Di Matteo
- Dipartimento di Medicina Sperimentale, Sez. Fisiologia Umana e Funzioni Biologiche Integrate, Università degli Studi della Campania 'Luigi Vanvitelli', via Santa Maria di Costantinopoli, 16-80138 Napoli, Italy
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Siegel DS, Al-baghdadi YH, Frangello M, Herrboldt M, Alvino S, Trauth SE, Sever DM. “Sexual tears” in a salamander? ZOOMORPHOLOGY 2017. [DOI: 10.1007/s00435-016-0342-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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De Rienzo G, Di Sena R, Ferrara D, Palmiero C, Chieffi Baccari G, Minucci S. Temporal and spatial localization of prothymosin alpha transcript in the Harderian gland of the frog, Rana esculenta. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 2002; 292:633-9. [PMID: 12115928 DOI: 10.1002/jez.10097] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Harderian gland (hg) is the only orbital gland of the frog Rana esculenta, and it has the essential function of lubricating the eyes. The hg secretory activity is seasonal, showing the highest value in summer. There is, at present, no data on gene expression of the frog hg. This study reports, for the first time, on the temporal and spatial expression of a cDNA clone encoding for the prothymosin alpha (Prot-alpha), a highly acidic nuclear protein present in virtually all mammalian cells. Northern blot analysis revealed a single 1.7 kb transcript detected in the frog hg throughout the year, with a lowest expression in September in concomitance with the minimum secretory activity. In situ hybridization indicated that hg secretory cells express Prot-alpha transcript, and the hybridization signal was less intense in the September gland. The constant expression of the frog Prot-alpha mRNA during the whole year suggests a constitutive role for this molecule in the hg. In addition, taking into account that, in mammals, many immunomodulatory functions have been attributed to this protein, it is suggested that frog Prot-alpha might contribute to the hg immunity processes, probably acting as a protective agent against infections of the eyeball. Interestingly, although the presence of Prot-alpha gene in animals other than mammals has been considered to be highly unlikely, the present paper confirms the presence of Prot-alpha transcript in a nonmammalian vertebrate, the frog R. esculenta.
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Affiliation(s)
- Gianluca De Rienzo
- Dipartimento di Medicina Sperimentale, Sezione di Fisiologia Umana e Funzioni Biologiche Integrate, F. Bottazzi, Seconda Università degli Studi di Napoli, 80138 Napoli, Italy
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Varriale B, Chieffi P. Oestrogen control of the sexual dimorphism in the Harderian gland of Xenopus laevis. J Steroid Biochem Mol Biol 1997; 62:455-60. [PMID: 9449249 DOI: 10.1016/s0960-0760(97)00050-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Xenopus laevis shows a sexual dimorphism of the electrophoretic pattern of Harderian gland (HG) proteins. The male pattern displays three protein fractions whose molecular sizes are approx. 205, 180 and 78 kDa, respectively, and which are absent in the female pattern. Conversely, the female pattern displays two protein fractions of approx. 190 and 76 kDa, respectively. This sexual dimorphism led us to hypothesize a sex steroid control of the HG. Administration of 17beta-oestradiol to male Xenopus converts the male protein pattern into the female one, while the administration of testosterone to the female has no effect. In this respect neither Northern analysis nor the RNase-protection assay performed using a 213 bp encoding for the androgen-binding domain reveals the presence of an androgen receptor mRNA in Xenopus HG. Conversely, Northern analysis has shown an oestrogen receptor mRNA whose size is approx. 6.5 kb and the RNase-protection assay performed by using a 197 bp encoding for the oestrogen-binding domain has also displayed the presence of an oestrogen receptor mRNA in the female HG but not in the male one. In addition, the oestrogen administration to male Xenopus induces the appearance of an oestrogen receptor mRNA. Androgen administration to female toad is ineffective. Taken together, all these findings suggest that in Xenopus laevis oestrogens are involved into the HG physiology. The appearance of an oestrogen receptor mRNA in the oestradiol treated males supports the hypothesis of the occurrence of autoinduction of oestrogen receptor mRNA expression in the HG.
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Affiliation(s)
- B Varriale
- Dipartimento di Fisiologia Umana e Funzioni Biologiche Integrate F. Bottazzi, Seconda Università di Napoli, Italy
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Payne AP, Shah SW, Marr FA, McGadey J, Thompson GG, Moore MR. Hormones and the control of porphyrin biosynthesis and structure in the hamster harderian gland. Microsc Res Tech 1996; 34:123-32. [PMID: 8722706 DOI: 10.1002/(sici)1097-0029(19960601)34:2<123::aid-jemt5>3.0.co;2-t] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The hamster Harderian gland seems to present both an excellent model for the control of porphyrin biosynthesis and an unusually robust example of the interrelationship between structure and function. It has been known for some time that 1) the capacity for manufacturing and storing porphyrins and 2) gland histology and ultrastructure are controlled by androgens. Thus, in intact males as well as in gonadectomised animals of either sex treated with androgens, porphyrin synthesis by the Harderian gland is suppressed and the gland tubules characteristically possess two cell types, the cytoplasm of both containing polytubular complexes. By contrast, the Harderian glands of intact females and castrated males synthesise and store large amounts of protoporphyrin, while their tubules possess only one cell type which lacks a polytubular complexes. So overarching is the effect of androgens that they have been described as a "coarse tuning" effect on the gland. By contrast, the role of the ovary is both less dramatic and less well understood. In female hamsters, ovariectomy leads to degenerative changes in Harderian gland tubules and (probably) a release of stored porphyrin; at the same time there is a reduction in enzyme levels and new synthesis. The causative hormone in this "fine tuning" is unclear at present. There is now clear evidence that the Harderian gland is also controlled directly by pituitary hormones. In particular, the use of continuous infusion osmotic minipumps has allowed us to demonstrate not only 1) that the expected rise in porphyrins and feminisation of gland morphology does not occur in castrated males receiving the dopamine agonist bromocriptine, but that 2) the simultaneous administration of prolactin does permit these changes; furthermore, 3) the administration of prolactin alone increases porphyrin synthesis above the levels found in untreated castrates. Similarly, bromocriptine administration to ovariectomised females markedly reduces porphyrin synthesis and masculinises gland structure; again, this is reversed by the simultaneous administration of prolactin. Prolactin must therefore be seen as equipotent with androgens in determining gland structure and activity.
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Affiliation(s)
- A P Payne
- Department of Anatomy, Glasgow University, Scotland
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Chieffi G, Baccari GC, Di Matteo L, d'Istria M, Minucci S, Varriale B. Cell biology of the harderian gland. INTERNATIONAL REVIEW OF CYTOLOGY 1996; 168:1-80. [PMID: 8843648 DOI: 10.1016/s0074-7696(08)60882-7] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The harderian gland is an orbital gland of the majority of land vertebrates. It is the only orbital gland in anuran amphibians since the lacrimal gland develops later during phylogenesis in some reptilian species. Perhaps because it is not found in man, little interest was paid to this gland until about four decades ago. In recent years, however, the scientific community has shown new interest in analyzing the ontogenetic and morphofunctional aspects of the harderian gland, particularly in rodents, which are the preferred experimental model for physiologists and pathologists. One of the main characteristics of the gland is the extreme variety not only in its morphology, but also in its biochemical properties. This most likely reflects the versatility of functions related to different adaptations of the species considered. The complexity of the harderian gland is further shown in its control by many exogenous and endogenous factors, which vary from species to species. The information gained so far points to the following functions for the gland: (1) lubrication of the eye and nictitating membrane, (2) a site of immune response, particularly in birds, (3) a source of pheromones, (4) a source of saliva in some chelonians, (5) osmoregulation in some reptiles, (6) photoreception in rodents, (7) thermoregulation in some rodents, and (8) a source of growth factors.
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Affiliation(s)
- G Chieffi
- Dipartimento di Fisiologia Umana e Funzioni Biologiche Integrate Filippo Bottazzi, Seconda Università di Napoli, Naples, Italy
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Di Matteo L, Chieffi Baccari G, Chieffi P, Minucci S. The effects of testosterone and estradiol on mast cell number in the harderian gland of the frog, Rana esculenta. Zoolog Sci 1995; 12:457-66. [PMID: 8528017 DOI: 10.2108/zsj.12.457] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The Harderian gland (HG) of the frog Rana esculenta contains mast cells in the interstitial tissue. The mast cell number (MCN) is influenced by sex hormones. Gonadectomy in both sexes provoked a decrease in MCN in January, while no effect was observed in September. Sex hormone-replacement therapy gave different results; estradiol treatment in castrated males and females always increased MCN, while testosterone did not. Acute estradiol treatment provoked an increase in MCN on days 2 and 4 of treatment and the morphology of the glandular compartment appeared normal. On days 8, 10 and 12 of treatment the MCN drastically decreased. The majority of glandular acini appeared strongly disorganized and the interstitial tissue became hypertrophic in concomitance with an increased vascularization. Our results suggest that estradiol acts by stimulating mast cells and acute estradiol treatment provokes proliferation of interstitial connective tissue together with glandular cells damage.
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Affiliation(s)
- L Di Matteo
- Dipartimento di Fisiologia Umana e Funzioni Biologiche Integrate F. Bottazzi, Napoli, Italy
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Varriale B, Serino I. The androgen receptor mRNA is up-regulated by testosterone in both the Harderian gland and thumb pad of the frog, Rana esculenta. J Steroid Biochem Mol Biol 1994; 51:259-65. [PMID: 7826887 DOI: 10.1016/0960-0760(94)90038-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Alpha 32P-labelled cDNA probe from plasmid containing rat androgen receptor (rAR) has been tested in hybridization experiments using RNAs from the Harderian gland and thumb pad of the edible frog, Rana esculenta. Northern blot analysis has shown a high degree of homology between the rAR cDNA and the frog androgen receptor mRNA (fAR mRNA); this has been supported by both the hybridization conditions (high stringency) and the molecular size of fAR mRNA which is quite similar to those described in mammals (9.4 kb). The role of androgens has been further investigated with respect to the kinetics of expression of fAR mRNA in in vivo experiments. In both the Harderian gland and thumb pad, testosterone has increased the levels of fAR mRNA as compared with the untreated groups. The use of cyproterone acetate (CPA) in combination with testosterone has resulted in a loss of the increase in fAR mRNA as compared to testosterone-treated groups, while CPA alone has resembled the control group. In primary cultures of frog Harderian gland and thumb pad cells, the steady-state levels of fAR mRNA have been increased in the cells exposed to testosterone as compared to those not exposed. These findings confirm that, in these androgen target tissues, testosterone exerts an up-regulation on its own receptors, increasing the accumulation of fAR mRNA in the same way as oestrogens up-regulate the expression of their own receptors in Xenopus liver and oviduct cells.
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Affiliation(s)
- B Varriale
- Dipartimento di Fisiologia Umana e Funzioni Biologiche Integrate F. Bottazzi, Facoltà di Medicina e Chirurgia, II Università di Napoli, Italy
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Chieffi-Baccari G, D'Matteo L, d'Istria M, Minucci S, Serino I, Varriale B. The effects of gonadectomy and testosterone treatment on the Harderian gland of the green frog, Rana esculenta. Cell Tissue Res 1993; 273:201-8. [PMID: 8364965 DOI: 10.1007/bf00312821] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effects of gonadectomy and testosterone treatment on the fine structure of the Harderian gland in male and female green frogs were investigated in different periods of the year. Gonadectomy, carried out when the glands are in the lowest secretory phase (September), causes degenerative changes consisting of a reduction of the rough endoplasmic reticulum, the appearance of autolysosomes, and an increase of nuclear heterochromatin. These effects can be prevented by testosterone treatment. No castration effects are found during the recovery (November) and enhancement (April-May) phases of secretory activity. The results suggest that the frog Harderian gland's sensitivity to testosterone changes during the annual cycle. The androgen dependence of the Harderian gland is correlated with the presence of androgen receptors in both male and female frogs.
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