Proliferative response of seminal vesicle cells to androgen and estrogen in neonatally castrated mice

Proliferation and death of androgen- and estrogen-responsive cells in seminal vesicles were compared between neonatally and adult (on Day 60 after birth) castrated mice. Daily injections of either testosterone propionate (TP) or estradiol-17 beta (E2) were started on Day 90 after birth; the incorporation of 5-[125I]iodo-2'-deoxyuridine ([125I]IdUrd) into the whole seminal vesicles was used as an index for proliferation. Although the peak of [125I]IdUrd uptake was observed 3 days after starting TP injections in both neonatally and adult castrated mice, the peak was lower and the period of proliferation was much longer in the former than in the latter. When TP injections were stopped, the fraction of surviving cells that synthesized DNA on Day 3 of TP injections was much larger in neonatally than adult castrated mice. The difference was attributed to the presence of TP-induced proliferation of fibromuscular cells in the neonatally castrated mice but not in the adult castrated mice; only the fibromuscular cells but not epithelial cells survived after stopping TP injections. Although injections of E2 increased the proliferation of epithelial cells but did not the weight of seminal vesicles in adult castrated mice, the same procedure increased the proliferation of both epithelial and fibromuscular cells and the weight in neonatally castrated mice. The E2-induced fibromuscular cells seemed to survive in the presence or absence of E2. The present results seem to indicate that androgen- and estrogen-induced proliferation of fibromuscular cells is irreversible in seminal vesicles of neonatally castrated mice and that the depletion of androgen in the seminal vesicle during neonatal and prepubertal periods is at least in part compensated by the administration of androgen, even after 90 days of age.     

INFLUENCE OF METABOLIC DNA ON DETERMINATIONS OF THE CELL CYCLE

Abstract. Evidence in favour of labelling of DNA in excess of requirements for mitosis was found in adult organs showing no mitosis (heart muscle and brain), in organs with low mitotic indexes (liver, seminal vesicle) and, more recently, in the small intestine of rodents, in bone formation and in growing roots of Vicia faba. A survey of published data showed higher labelling indexes than would be expected from the data for S, M and t _c deducted from labelled mitoses curves. to improve the accuracy of the data needed for a complete assessment the duration of mitosis (M) and the proportion of cells which are no longer in the mitotic cycle in the crypts were determined using Colcemid. the fact that all cells in the villi are derived from the crypts and that there is no cell-loss in the villi was checked by cell-counts.
The results show that 3040%of the labelled nuclei found in crypts of the jejunum of mice at 1 hr after injection of ³H-thymidine do not proceed to mitosis.
The labelling after the last mitosis is interpreted as formation of the metabolic DNA necessary for the function of the differentiated cells in the villi. There is some evidence that metabolic DNA necessary for the processes of mitosis might be lost     

Increase in epithelial cell growth by hyperprolactinemia induces delay of castration-induced involution of mouse seminal vesicle

Male (C57BL/6 x DBA)F1 hybrid mice were castrated on day 60 after birth; two pituitaries from 60-day-old female mice were immediately grafted under the capsule of the left kidney in half of the castrated mice to induce hyperprolactinemia. The seminal vesicles in the absence of androgen treatment were examined 15, 22, 30 and 60 days after castration with or without grafting. Significant increases in the weight (1.3-1.4-fold), DNA content (1.2-1.3-fold) and labeling index of epithelial cells (4-10-fold) of the seminal vesicles were found in mice with pituitary grafts compared to mice without grafts on days 15-30 after castration but not on day 60 after castration. Such stimulatory effects of hyperprolactinemia on mouse seminal vesicle cells were also observed on day 15 after castration plus adrenalectomy. Cell loss from the seminal vesicles was found to be similar in castrated mice with and without the grafts. The present findings demonstrate that hyperprolactinemia induces an increase in DNA synthesis of epithelial cells in the seminal vesicles until 30 days after castration and results in a significant delay of castration-induced involution of the weight and DNA content of the seminal vesicles for 1 month. However, the delay with increased epithelial cell growth by hyperprolactinemia disappeared 60 days after castration.     

Can cells extruded from denervated skeletal muscle become circulating potential myoblasts?

Summary The hypothesis that satellite cells which leave denervated skeletal muscle might become circulating potential myoblasts which could participate in myogenesis in distant sites in the body has been tested.Sixteen mice had one hindlimb denervated and were given 7 daily injections of ³H-thymidine (³H-Tdr). One day later extensor digitorum longus muscle isografts from unlabelled mice were inserted into each hindlimb. As controls, the procedure was repeated in 6 non-denervated labelled mice. Fourteen days after their insertion, isografts in denervated mice contained many labelled myotubes with a labelling index of 55±4% (mean±SEM). In the control isografts in non-denervated mice, 38±4% of myotube nuclei were labelled. The results show that either labelled cells, or ³H-Tdr, had transferred from the host to isografts in both cases. The probability of ³H-Tdr reutilization was demonstrated in regenerating livers of 8 similarly labelled mice, where 34±3% hepatocytes adjacent to crush lesions were labelled after 14 days. This conclusion was reached because only 2–3% of normal hepatocytes incorporate ³H-Tdr under these conditions and this population is inadequate to provide sufficient labelled precursor cells for the large numbers of labelled regenerated hepatocytes. Therefore, it was concluded that ³H-Tdr reutilization is the most likely explanation for labelled myotube nuclei in the muscle isografts (rather than movement of labelled precursor cells), and that additional label for reutilization had been derived from breakdown of labelled cells in denervated muscle. The data do not support the hypothesis of a circulating precursor for skeletal muscle cells.     

Effect of long term androgen removal on androgen-induced proliferation of seminal vesicle cells in adult mice

Male mice were castrated on day 60 after birth; daily injections of testosterone propionate (TP, 4 micrograms/g b.wt) were started 1.2 or 6 months after the castration. The incorporation of 5-[125I]iodo-2'-deoxyuridine [( 125I]IdUrd) into the whole seminal vesicles was determined on various days after starting the TP injections as an index for proliferation. Although the peak of [125I]IdUrd uptake was observed 3 days after starting the TP injections in both short (1-2 months) and long (6 months) term castrated mice, the peak was significantly lower and the period of proliferation was longer in the long term group than in the short term group; the weights of seminal vesicles before TP injections were 6 and 10 mg in the long and short term groups, respectively. Although TP injections induced the proliferation of only epithelial cells in the short term group, the same treatment induced the proliferation of both epithelial and fibromuscular cells in the long term group. The deficient responsiveness to androgen of the seminal vesicle cells found in the long term castrated mice was completely recovered by TP pretreatment for 2 weeks. The present findings suggest that so-called imprinted cells in the mouse seminal vesicle induced by neonatal and prepubertal testicular androgens are very slowly lost at least in part by androgen removal for long periods such as more than 6 months in adult mice and that the loss is at least in part due to the death of fibromuscular cells, which is recovered rather quickly by androgen pretreatment.     

The proliferation of adrenal medullary cells in newborn and adult mice

Summary The proliferative activity of newborn and adult mouse adrenal medullary cells was determined with light and electron microscopic autoradiography. The H³ thymidine labelling index of 2 weeks old mice adrenal medullary cells was about 9.4 % and declined to less than 1 % in adult mice. In electron microscopic autoradiography labelled norepinephrine as well as epinephrine cells could be seen. Only in 1 and 2 weeks old mice some morphologically undifferentiated cells were visible. In formaldehyde induced fluorescence combined with light microscopic autoradiography the fluorescence intensities of labelled and unlabelled medullary cells were measured. On average the fluorescence intensity of labelled cells was lower than that of unlabelled cells. The differences could be explained by a higher number of autoradiographic silver grains laying on the cytoplasm of labelled cells. These results give evidence that fully differentiated adrenal medullary cells are capable of division.This study was supported by Jubiläumsfonds der Österreichischen Nationalbank grant No. 818     

Hesr1 and Hesr3 are essential to generate undifferentiated quiescent satellite cells and to maintain satellite cell numbers

Satellite cells, which are skeletal muscle stem cells, divide to provide new myonuclei to growing muscle fibers during postnatal development, and then are maintained in an undifferentiated quiescent state in adult skeletal muscle. This state is considered to be essential for the maintenance of satellite cells, but their molecular regulation is unknown. We show that Hesr1 (Hey1) and Hesr3 (Heyl) (which are known Notch target genes) are expressed simultaneously in skeletal muscle only in satellite cells. In Hesr1 and Hesr3 single-knockout mice, no obvious abnormalities of satellite cells or muscle regenerative potentials are observed. However, the generation of undifferentiated quiescent satellite cells is impaired during postnatal development in Hesr1/3 double-knockout mice. As a result, myogenic (MyoD and myogenin) and proliferative (Ki67) proteins are expressed in adult satellite cells. Consistent with the in vivo results, Hesr1/3-null myoblasts generate very few Pax7(+) MyoD(-) undifferentiated cells in vitro. Furthermore, the satellite cell number gradually decreases in Hesr1/3 double-knockout mice even after it has stabilized in control mice, and an age-dependent regeneration defect is observed. In vivo results suggest that premature differentiation, but not cell death, is the reason for the reduced number of satellite cells in Hesr1/3 double-knockout mice. These results indicate that Hesr1 and Hesr3 are essential for the generation of adult satellite cells and for the maintenance of skeletal muscle homeostasis.     

Effect of androgen pretreatments at adulthood on androgen-induced proliferative response of seminal vesicles in neonatally castrated mice

Male mice were castrated on days 0 and 60 after birth. The majority of the neonatally castrated mice were pretreated with androgen; the mice were given daily injections of testosterone propionate (TP; 4 or 8 micrograms/g body wt) for 20 or 30 days starting from day 60. Daily injections of TP (4 micrograms/g body wt) to examine androgen-induced proliferation were started from day 30 or 60 after the end of TP pretreatments or from day 60 after castration; on various days after starting TP injections, the weight and the incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles were determined as indices for proliferation. The seminal vesicles of neonatally castrated adult mice were characterized by long duration of androgen-induced proliferation (greater than 20 days) with a low peak (neonatal castration type), whereas the seminal vesicles of adult castrated mice were characterized by short duration of proliferation (10 days) with a high peak (adult castration type). In neonatally castrated adult mice, the neonatal castration type of androgen-induced proliferation was changed largely to the adult castration type when pretreatment with 8 micrograms/g body wt of TP had been given for 30 days. However, this effect gradually disappeared when the mice had been pretreated with decreasing amounts of TP for a shorter period. The present findings suggest that the defect in the androgen-induced proliferative response of mouse seminal vesicles induced by the absence of neonatal and prepubertal testicular androgens can be compensated by androgens given in adulthood, if enough androgen is given for a sufficiently long time.     

Induction of functional cytodifferentiation in the epithelium of tissue recombinants. I. Homotypic seminal vesicle recombinants

Functional cytodifferentiation of seminal vesicle epithelium was investigated in tissue recombinants. Neonatal rat and mouse seminal vesicles were separated into epithelium and mesenchyme using trypsin. Epithelium and mesenchyme were then recombined in vitro to form interspecific rat/mouse homotypic recombinants. Growth as renal grafts in adult male athymic mice resulted in seminal vesicle morphogenesis in 70% of the recombinants (the remaining 30% failed to grow). Functional cytodifferentiation was judged by the expression of the major androgen-dependent secretory proteins characteristic of the seminal vesicles of adult rats and mice. Antibodies specific for each of these proteins were used to screen tissue sections by immunocytochemistry and to probe protein extracts by immunoblotting techniques. The heterospecific recombinants synthesized the full range of seminal vesicle secretory proteins that typifies the species providing the epithelium of the recombinant, not the mesenchyme. There was little functional variation between individual recombinants. The time course of development corresponded to that of intact neonatal seminal vesicles grown under the same conditions. Morphogenesis and functional cytodifferentiation were not evident after one week, but were well advanced after two weeks. Seminal vesicle recombinants grown for three weeks were indistinguishable morphologically and functionally from normal adult seminal vesicles. In addition, the ability of adult seminal vesicle epithelium to be induced to proliferate was examined. In association with neonatal seminal vesicle mesenchyme, the epithelium of the adult seminal vesicle proliferated and retained its normal functional activity. Thus, seminal vesicle functional cytodifferentiation can be faithfully reproduced in homotypic tissue recombinants. The methods used in this study will be used to investigate seminal vesicle development in instructive inductions of heterotypic epithelia.     

Proliferative response of seminal vesicle cells to androgen in mice castrated neonatally and pretreated with estrogen or androgen at adulthood

Seminal vesicle cells of neonatally castrated adult mice show poor response to androgen, compared to those of mice castrated at adulthood; effects of pretreatment with androgen or estrogen at adulthood on androgen-induced proliferation of the seminal vesicle cells were examined in neonatally castrated mice. Male mice castrated at day 0 after birth were pretreated with daily injections of testosterone propionate (TP, 100 micrograms/mouse), 17 beta-estradiol (E2, 5 micrograms/mouse) or vehicle for 20 days starting from day 60; daily TP injections (100 micrograms/mouse) for 30 days were started again from day 110 in all the pretreated mice to examine androgen-induced proliferation by incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles. Both TP and E2 pretreatments significantly increased the seminal vesicle weight found before TP treatment. However, androgen-induced proliferation of the seminal vesicle found in neonatally castrated mice (poor response; long duration with a low peak on day 3) was changed at least in part to that found in mice castrated at adulthood (good response; short duration with a high peak on day 3) only following the TP pretreatment but not at all following the E2 pretreatment. The E2 pretreatment induced poor androgen-induced proliferation with a low peak on day 7.     

AUTORADIOGRAPHIC CONFIRMATION OF THE MITOTIC DIVISION OF EVERY MOUSE JEJUNAL CRYPT CELL LABELLED WITH 3H-THYMIDINE

The question was investigated of whether for crypt epithelia of the jejunum of the mouse all cells labelled after a single injection of ³H-TdR subsequently divide or whether cells exist in the crypt which synthesize metabolic DNA and, therefore, do not undergo division after labelling.
A double labelling experiment was performed with a first injection of ³H-TdR followed 1 hr later by an injection of ¹⁴C-TdR. Then from double emulsion autoradiographs of isolated squashed crypts the number of ³H-only, ¹⁴C-only and double labelled cells and mitoses were counted.
The double labelling produced a narrow, 1 hr wide sub-population of ³H-only labelled cells. This subpopulation of S cells completed its division before labelled cells were lost from the crypts by migration onto the villi. The results showed that this subpopulation of ³H-only cells completely doubled within 3 hr and then remained constant through 6 hr. From this result it was concluded that every cell labelled after a single injection of ³H-TdR divides.
From the same autoradiographs the flow rate through the end of mitosis was measured. From the flow rate and the mitotic index a mitotic duration of 0·5 hr was determined. The agreement of this measured mitotic time with the value calculated from the labelling index, mitotic index and S duration is also strong evidence that every labelled cell divides.
Both experiments show that the intestinal crypt does not contain cells synthesizing metabolic DNA.     

Interlinear differences in generative function formation in pubescence of male mice

The formation of generative function in pubescence is studied in males of three inbred mice lines BALB/cLac, CBA/Lac, and PT. From days 35 through 60 of life every 5 days the amount of sperm cells and the quantity of abnormal heads of spermatozoa in males are calculated in both epididymises and the morphometry of the testicles, epididymises, and seminal vesicles is carried out. Interlinear deviations in the pubertal dynamics of the parameters of spermatogenesis and the morphometric indexes are determined, indicating a weak spermatogenesis process in males of CBA/Lac in comparison with males from the other lines. Males from the line CBA/Lac are characterized by a low amount of epididymal spermatozoa combined with low frequency of abnormal spermatozoon heads; these traits can be considered as a compensatory process that increases fertility. By the end of the period, i.e., on days 55–60 of life, the males of all three inbred mice lines have not reached the definitive level in the number of epididymal spermatozoa; the weight of the testicles, epididymise, and seminal vesicles; and body weight. Thus, in laboratory mice, the beginning of reproductive activity is not connected with these reproductive indexes reaching the definitive level. The results of the study show that in adult mature males of laboratory mice the interlinear deviations in generative function emerge in the pubertal period and persist thereafter.     

Roles of prepubertal androgen, estrogen or androgen plus prolactin on androgen-induced proliferative response of seminal vesicles in adult mice

Male mice castrated on day 0 after birth were pretreated daily with testosterone propionate (TP, 4 micrograms/g body weight), 17 beta-estradiol (E2, 0.2 micrograms/g body weight) or vehicle for 21 days starting from day 20. In another experiment, male mice were castrated on day 25; two pituitaries from 60-day-old females were immediately grafted under the capsule of the left kidney in one group. The castrated mice with or without grafts were pretreated daily with TP (4 or 20 micrograms/g body weight) for 36 days starting from day 25, and the left kidney was removed on day 60. Daily TP injections (4 micrograms/g body weight) were started again at 30 days after the end of pretreatments to examine androgen-induced proliferation, and incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles was used as an index of proliferation. In the neonatally castrated mice, both TP and E2 pretreatments given during the prepubertal period significantly increased seminal vesicle weight even long after the end of the pretreatments. However, androgen-induced proliferative response found in the neonatally castrated adult mice (poor response; long duration with a low peak) was changed to that found in mice castrated at adulthood (good response; short duration with a high peak) by the TP pretreatment only but not at all by the E2 pretreatment. In the mice castrated on day 25, a pharmacological dose of TP or TP plus hyperprolactin could not enhance or change the adult castration type of androgen-induced proliferation induced by physiological prepubertal androgens, although both treatments significantly enhanced the prepubertal growth of the seminal vesicles.     

Melatonin administration induced reactivation in the seminal gland of the soay rams during non‐breeding season: An ultrastructural and morphometrical study

Fifteen adult Soay rams were used in this experiment. Eight animals were given subcutaneous implants containing melatonin, while the other seven animals were used as control. After 11 weeks, the rams were killed and the seminal vesicles were examined by light and electron microscope. In contrast to the control grouped animals, the melatonin treated rams showed morphological, morphometrical, and ultrastructural changes as a result of reactivation of the glandular tissues of the seminal glands. The ratio of interstitial connective tissues to glandular tissues was reduced in the treated group. Melatonin induced an evident significant increase in number and height of principal cells that showed signs of increased secretory activity; apical cytoplasmic protrusions became well developed and covering the inner surface of the glandular end‐pieces, also, the basal cells were significantly increased in number. The main cytological alteration in the principal cells of the seminal vesicles in treated animals was prominent increase in the concentrically arranged membranes of sER, secretory vacuoles and glycogen granules and appearance of numerous lysosomes and multivesicular bodies. Interstitial Cajal‐ like cells were significantly increased in number and formed a network around the epithelium and between smooth muscle cells in the treated group. The main components of these cells were mitochondria, rER, sER, and many caveolae. The cytological alterations were accompanied by subepithelial and intraepithelial nonmyelinated nerve terminals in the treated animals. The results support the view that melatonin activates and increases the secretory activity of seminal gland in sheep. J. Morphol. 277:231–243, 2016. © 2015 Wiley Periodicals, Inc.     

Reutilisation of tritiated thymidine in studies of regenerating skeletal muscle

Summary Two different aspects of tritiated thymidine (³H-Tdr) reutilisation in skeletal muscle were examined. Injection of a high dose (7 Ci/g) of ³H-Tdr into mice prior to crush injury of skeletal muscle resulted in heavy labelling (grain counts) of myotube nuclei 9 d later. In contrast, myotube nuclei were essentially unlabelled when a low dose (1 Ci/g) of ³H-Tdr was injected at similar times with respect to injury. It was concluded that labelling seen after the high dose was due to reutilisation of ³H-Tdr. (Such ³H-Tdr reutilisation can account for the results of Sloper et al. (1970) which previously supported the concept of a circulating muscle precursor cell.) When replicating muscle precursors were labelled directly with ³H-Tdr 48 h after injury, the percentages of labelled myotube nuclei and the distribution of nuclear grain counts were similar with either high or low dose.We also investigated whether the light labelling seen in regenerated myotube nuclei after 9 d, when ³H-Tdr had been injected before the onset of myogenesis (as found by McGeachie and Grounds 1987), was due to ³H-Tdr reutilisation or, alternatively, to proliferation of local cells in the wound which subsequently gave rise to muscle precursors. Labelling of myotube nuclei was compared in mice injected with ³H-Tdr either 2 h before, or 2 h after injury. In another experiment, mice were injected 12 h after injury and lesions sampled 1, 12 or 36 h later, to see whether local cells were replicating 12 h after injury, and what labelled cells subsequently entered to wound. No difference was found in myotube labelling between mice injected before or after injury, and no cells replicating locally in the wound at 12 h after injury were observed. The results clearly show that the light labelling was due to ³H-Tdr reutilisation.     

Effects of castration and of oestradiol treatment on the subcellular structure of the mouse seminal vesicles, with particular reference to the function of the Golgi apparatus and the lysosomes

Synopsis A number of changes were observed in the ultrastructure of seminal vesicles from castrated mice fed continuously with oestradiol. Treatment for two weeks was accompanied in the epithelial cells by the disappearance of secretion droplets, swelling of the Golgi structures and the appearance of many dense bodies and vesicles of various sizes. Subsequently, there was a decrease in the amount of rough endoplasmic reticulum followed by the disappearance of the vesicles. These changes were paralleled by a decrease in size and, finally, disappearance of the dense bodies, and by the appearance of abnormal nuclei. Ultimately, the epithelial cells became packed with free ribosomes and keratinization of the epithelium ensued.These metaplastic phenomena in the epithelium were accompanied by thickening and infolding of the basement membrane and by the formation of several layers of smooth muscle cells. The latter cells were very abnormal in that they contained prominent Golgi apparatuses and a vesiculated cytoplasm.When vesiculation occurred, both in the epithelium and in the cells of the basal areas of the acini (myoepithelial, basal and muscle cells), the vesicles, the Golgi bodies and the dense bodies (lysosomes) contained acid naphthol-AS-phosphatase activity. This enzyme was different from the more commonly described lysosomal acid -glycerophosphatase in that it was not inhibited by either sodium fluoride or sodium molybdate; in certain instances its activity in the cisternae of the endoplasmic reticulum could be shown to be enhanced by these compounds. The significance of these findings is discussed.     

Effects of X-irradiation and adriamycin on quiescent and proliferating cells of the seminal vesicle in the castrated mouse

The sensitivity of resting and proliferating cells of the seminal vesicle to X-irradiation and adriamycin has been investigated. Stimulation with testosterone propionate (250 μg/day) was started 11 days after castration in BALB/c mice. X-rays (2.5–7.5 Gy total body irradiation) and intraperitoneal injections of adriamycin (4–16 mg/kg body weight) were administered at various times before or after induction of proliferation by testosterone injection. The DNA contents and the weights of the seminal vesicles were determined at 4 days after the start of stimulation. A D₀ for X-rays of about 10 Gy was found for the seminal vesicle epithelium. For both X-irradiation and adriamycin no significant differences in sensitivity were observed between quiescent (G₀) and proliferating (G₁; S) seminal vesicle cells.     

Roles of neonatal and prepubertal testicular androgens on androgen-induced proliferative response of seminal vesicle cells in adult mice

Male mice were castrated at 0, 10, 20, 30, 40 and 60 days of age; daily injections of testosterone propionate (TP, 4 micrograms/g b. wt) were started from day 90. On various days after starting the TP injections, the incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles was determined as an index for proliferation. The seminal vesicle cells in mice castrated on days 0 and 20 were characterized by low weight (0.5-1 mg) before TP injection, long duration of androgen-induced proliferation (greater than 20 days) with a low peak, and involvement of both epithelial and fibromuscular cells (neonatal castration type). The seminal vesicle cells in mice castrated on days 60 and 40 were characterized by relatively high weight (5-10 mg) before TP injection, short duration of androgen-induced proliferation (10 days) with a high peak, and involvement of only the epithelial cells (adult castration type). In mice castrated on days 0 and 20, the neonatal castration type of androgen-induced proliferation was completely changed to the adult castration type when TP pretreatment (2 micrograms/g b. wt per 12 h) had been given from day 20 to day 40. However, the TP pretreatment given from day 90 to day 110 instead of days 20-40 had no such effect in 140-day old mice castrated on day 0. The present findings suggest that testicular androgens secreted from day 20 to day 40 play an indispensable role in the induction of irreversible proliferative response of the mouse seminal vesicle. The activity of the prepubertal androgens may not be completely compensated by androgen activity at adulthood.     

Male reproductive effect of nickel sulphate in mice

Nickel sulphate was administered orally to adult male mice at dose level of 5 and 10 mg/kg body weight (5 days per week) for 35 days. There was no change in body weight. However a significant decrease in absolute and organ-to-body weight ratios of testes, epididymides, seminal vesicles and prostate gland was observed. The sperm abnormality, associated with decrease in sperm motility and sperm count was also observed. Significant alterations in the activities of marker testicular enzymes, viz. sorbitol dehydrogenase (decreases), lactate dehydrogenase (increases) and -glutamyl transpeptidase (increases) associated with histopathological changes in testes, epididymides and seminal vesicles, were also observed. Accumulation of nickel in testes, epididymides and seminal vesicles was also observed. The study reveals that the oral exposure to nickel may affect the histology of testes, epididymides, seminal vesicles and sperms morphology. These testicular and spermatotoxic changes may be responsible for observed male mediated developmental toxic effects.     

First evidence of DAAM1 localization in mouse seminal vesicles and its possible involvement during regulated exocytosis

Dishevelled-associated activator of morphogenesis 1 (DAAM1) is a protein belonging to the formin family, which regulates, together with the small GTPase RhoA, the nucleation and the assembly of actin fibres through Wnt-Dishevelled PCP pathway. Its role has been investigated in essential biological processes, such as cell polarity, movement and adhesion during morphogenesis and organogenesis. In this work, we studied the expression of DAAM1 mRNA and protein by PCR and Western blot analyses and its co-localization with actin in adult mouse seminal vesicles by immunofluorescence. We show that both proteins are cytoplasmic: actin is evident at cell–cell junctions and at cell cortex; DAAM1 had a more diffused localization, but is also prominent at the apical plasmatic membrane of epithelial cells. These findings support our hypothesis of a role of DAAM1 in cytoskeletal rearrangement that occurs during the exocytosis of secretory vesicles, and in particular concerning actin filaments. We were also able to detect DAAM1 and actin association in the smooth muscle cells that surround the epithelium too. In this case, we could only speculate the possible involvement of this formin in muscular cells in the maintenance and the regulation of the contractile structures. The present results strongly suggest that DAAM1 could have a pivotal role in vesicle exocytosis and in the physiology of mouse seminal vesicles.