Ultrastructural and biochemical features of efferent ducts (EDs) are indicative of an intense absorptive activity towards the luminal fluid. This function was investigated by 1) the immunohistochemical localization of different aquaporins, integral membrane water channels that facilitate rapid passive movement of water, and 2) the histochemical localization of lectins, known to have specific affinity for glycoconjugate residues. AQP1 was mostly revealed at the apical surface and adluminal cytoplasm of nonciliated cells and to a minor extent in their lateral plasma membrane, whereas it was absent in ciliated cells. Blood vessels showed AQP1-immunoreactivity, which was present in endothelial cells of venous vessels and capillaries and around the muscular sheath of arteries. AQP9 was expressed in the apical zone of ciliated and non-ciliated cells and in the lateral cell membrane. AQP2 and AQP5 were undetectable. Lectin histochemistry showed that non-ciliated cells contain glycans with terminal Neu5Aca2,3Galß1,3GalNAc, Neu5Aca2,3Galß1,4GlcNAc, Galß1,4GlcNAc, GalNAc (s-PNA, MAL II, RCA120, SBA reactivity) and with internal/terminal aMan (Con A affinity) at the luminal surface and the apical region. In addition, non-ciliated cells expressed oligosaccharides terminating with GalNAc and Neu5Aca2,6Gal/GalNAc (SNA reactivity) in the luminal surface and the apical zone, respectively. Ciliated cells revealed glycoconjugates only on cilia, which showed terminal Neu5Aca2,3Galß1,4GlcNAc (s- RCA120 staining) and GalNAc, as well as internal/ terminal aMan and GlcNAc (s-WGA, GSA II staining). Data provide evidence for the involvement of different pathways in the bulk reabsorption of water and low molecular weight solutes by the non-ciliated cell of the cat EDs. AQP-mediated trans-cellular route can be hypothesized, together with fluid phase endocytosis mediated by the glycocalix and a well-developed endocytotic apparatus. Epithelial ciliated cells, whose main function is the movement of luminal content, might also participate in absorptive processes to a lesser extent.

Recent investigations1 indicate that cat efferent ducts (EDs) play a role in reabsorption of the fluid and proteins leaving the testes, dependent also on androgen2. The males with Klinefelter syndrome (XXY) show a variable degree of androgen deficit responsible for testicular disfunction3. Since we demonstrated synthesis and secretion of glycoconjugates in normal cat EDs1, here we investigated the glycoprotein pattern of the EDs from a tricolor cat with Klinefelter syndrome (39,XXY), by means of the lectin histochemistry, utilizing a panel of 12 lectins in association with sialidase (s) treatment. Cilia of ciliated cells reacted with HPA, SBA, Con A, KOH-s-WGA, GSA II in normal cats and with MAL II, SNA, Con A and KOH-s-WGA in XXY cat. The luminal surface of non-ciliated cells bound MAL II, KOH-s-PNA, Con A in all samples, RCA120 and HPA only in normal subjects and PNA in XXY cat. The supra-nuclear cytoplasm of non-ciliated cells expressed SNA and Con A affinity in XXY cat and also MAL II, KOH-s-PNA, RCA120, SBA in normal cats. These results indicate that negative charges are mainly expressed on the cilia of XXY cat EDs, whereas a more complex glycoconjugate pattern, probably related to an more effective endocytotic apparatus, is expressed in the supra-nuclear cytoplasm of non-ciliated cells from normal EDs. References 1. Arrighi S et al. Histol. Histopathol. 2001, 25:433-44. 2. Jones RC. The epididymis: From molecule to clinical practice. Robaire and Hinton eds, Kluwer Academic/Plenum Publ. 2002,11-33. 3. Wikström AM and Dunkel L. Horm. Res. 2008, 69:317-26.

The oviduct plays an essential role in the mammalian reproduction and it undergoes significant endocrine-induced morphological, biochemical and physiological changes during the oestrous cycle. The functions of the oviduct epithelium are controlled by the ovarian steroids, oestrogen and progesterone1. In this study the glycoconjugate pattern of oviduct obtained from hormonally (FSH-P and eCG) superovulated ewes for oocytes recoverywas analyzed. Oviducts from treated and control sheep were collected by laparatomy, fixed in 4% (w/v) neutral formalin, embedded in paraffin wax and sections processed for lectin histochemistry. In the ampulla, the luminal surface of all specimens showed strong reactivity with MAL II,SNA, PNA after KOH-sialidase (s) treatment, RCA120, HPA, SBA, KOH-s-WGA, and GSA I-B4, whereas it stained strongly with GSA II, UEA I, and LTA in treated sheep which showed reactivity with KOH-s-PNA, SBA, GSA I-B4, GSA II also in the apical cytoplasm of non-ciliated cells. In the isthmus, the luminal surface showed same staining reactivity with RCA120, SBA, and GSA I-B4 in all specimens, and a stronger affinity for MAL II, UEA I and LTA in treated ones. A distinctive feature of hormonized isthmus was the binding of the entire cytoplasm of ciliated cells and non-ciliated cells with MAL II, SNA, RCA120, SBA, GSA II, UEA I, and LTA. These results indicate that ampulla and isthmus of ovine oviduct express a different glycoconjugate pattern and that the hormone administration for superovulation produces different effect along the oviduct. These differences could be related to the different functions of each segment that constitutes the ovine oviduct. 1. Buhi WC Reproduction 2002, 123:355-62.

The oviduct isthmus is considered to be a sperm reservoir prior to ovulation in the reproductive tract of mammals. Ovarian steroids regulate the synthesis and secretion of specific molecules such as glycoproteins that are involved in the interactions between germ cells or embryos and oviductal epithelial cells. The objective of the present study was to investigate the effects on histmus glycoprotein pattern from hormonally stimulated ewes by means of lectin histochemistry. Isthmus fragments were separated from oviducts immediately after laparatomy, and, after fixed in 4% (w/v) neutral formalin, they were embedded in paraffin wax. Then, the sections were stained with a panel of lectins which revealed: 1) an increase of reactivity with MAL II, SNA, RCA120, SBA, GSA I-B4, GSA II, UEA I and LTA in the whole cytoplasm of ciliated and non-ciliated cells of hormonally treated females, 2) a reduction of DBA affinity in the luminal surface, 3) no staining pattern modification with PNA, KOH-sialidase (s)- PNA, HPA, Con A and KOH-s-WGA. These results indicate that exogenous gonadotropin administration for superovulation may alter the oligosaccharidic composition of glycoproteins produced in the ovine isthmus.

Stallion sperm from semen collected in Southern Italy during the breeding (June–July) and non-breeding (December–January) periods were analyzed by means of twelve lectins to evaluate the glycoconjugate pattern and to verify whether there are any seasonal differences in the glycosylation pattern of the sperm glycocalyx. The acrosomal cap showed reactivity for Maackia amurensis (MAL II), Sambucus nigra (SNA), Arachis hypogaea (PNA), Glycine max (SBA), Helix pomatia (HPA), Canavalia ensiformis (Con A) Triticum vulgaris (WGA), and Griffonia simplicifolia isolectin II (GSA II) in breeding and non-breeding ejaculated sperm, suggesting the presence of oligosaccharides terminating with Neu5Aca2,3Galb1,4GlcNAc, Neu5Aca2,6Gal/GalNAc, with Galb1,3GalNAc, a/bGalNAc and glycans with terminal/internal aMan and GlcNAc. During the non-breeding period, the acrosomal cap expressed oligosaccharides terminating with Galb1,4GlcNAc (Ricinus communis120 affinity) (RCA120) and LFuca1,2Galb1,4GlcNAcb (Ulex europaeus affinity) (UEA I). The equatorial segment placed between the acrosomal cap and postacrosomal region did not display glycans terminating with GalNAc, GlcNAc, and aL-Fuc. The post-acrosomal region of sperm collected in the breeding and non-breeding periods bound Con A, MAL II, SNA, and SBA, thus showing the presence of N-linked oligosaccharides from high-Man content, terminating with Neu5Aca2,3Galb1,4GlcNAc, Neu5Aca2,6Gal/GalNAc and GalNAc. In winter, the post-acrosomal region also expressed oligosaccharides terminating with aGalNAc, GlcNAc, and L-Fuca1,2- Galb1,4GlcNAcb (HPA, GSA II, and UEA I staining). The tail of sperm from semen collected during the breeding and nonbreeding periods showed a lectin binding pattern similar to the post-acrosomal region, except for the absence of HPA staining in sperm collected during the winter season. These results indicate that the surface of stallion sperm contains different glycocalyx domains and that the glycosylation pattern undergoes changes during the breeding and non-breeding periods.

The receptor of the Thyroid Stimulating Hormone (TSHr) and thyroglobin (TGB), are two proteic factors necessary for the synthesis of hormones, in the thyrocite. In mammals, many immuno-histochemical reports indicate the presence of the TSHr in extra-thyroidal tissues, but not in the ovary. Triiodothyronine (T(3)) and thyroxine (T(4)) have been widely shown to affect ovarian functions and the synthesis of progesterone (P(4)). The aim of this study was to determine if by immunohistochemistry techniques TSHr and TGB could be found in the bovine corpora haemorragica, lutea and albicantia. A primary rabbit polyclonal antibody against human TSHr and a primary rabbit polyclonal antibody against human TGB were employed. Furthermore, the accuracy of bovine thyroid to the antibodies used in this study was tested. A positivity reaction for the anti-TSHr serum in the large luteal cells and immunostaining of both small and large luteal cells with the anti-TGB serum occurred only in mature corpora lutea. No immunostaining was detected in stromal cells, blood and lymphatic vessels and in corpora haemorragica and albicantia. Bovine thyroid tissue showed immunostaining to both the antibodies employed. These data suggest that the luteal cells of mature corpora lutea may be involved in the synthesis of thyroid hormones, which may modulate P(4) synthesis, acting in an autocrine and paracrine way.