Gestational nutrient restriction under extensive grazing conditions: Effects on muscle characteristics and meat quality in heavy lambs.

We evaluated maternal undernutrition effects induced by a lower natural pasture allowance (gestation days 30-143) on histological-biochemical and meat traits in muscles Semitendinosus, cranial Gluteobiceps and Supraspinatus from 200-day old male and female lambs. Maternal undernutrition increased oxidative and reduced glycolytic fibers in all muscles (P ≤ 0.01). Maternal undernutrition reduced the diameter of glycolytic fibers in the cranial Gluteobiceps of exclusively female lambs (P = 0.05) and reduced the diameter of oxidative fibers in the Supraspinatus of exclusively male lambs (P = 0.02). Maternal undernutrition increased lipid content in the Supraspinatus of females (P = 0.001), reduced lactate content (P = 0.03) and WB shear force (P = 0.02) in the Semitendinosus of females, and increased cooking losses in the Semitendinosus of males (P = 0.0069). In conclusion, gestational nutrient restriction induced fetal programming effects on muscle characteristics of lambs. Moreover, our study demonstrates that maternal undernutrition influences muscle and meat characteristics in a sex and muscle-dependent way.

Hyperthermia is more important than hypoxia as a cause of disrupted spermatogenesis and abnormal sperm.

We tested the hypothesis that hypoxia replicates effects of hyperthermia on reducing number and quality of sperm produced, whereas hyperoxia mitigates effects of hyperthermia. Forty-eight CD-1 mice (∼50 d old), inspired air with 13, 21, or 95% O2 and were exposed to ambient temperatures of 20 or 36 °C (3 × 2 factorial, six groups) twice for 12 h (separated by 12 h at 20 °C and 21% O2), with euthanasia 14 or 20 d after first exposure. Combined for both post-exposure intervals, there were primarily main effects of temperature; mice exposed to 20 vs 36 °C had differences in testis weight (110.2 vs 96.9 mg, respectively; P < 0.0001), daily sperm production (24.7 vs 21.1 × 106 sperm/g testes, P < 0.03), motile sperm (54.5 vs 41.5%, P < 0.002), morphologically normal sperm (59.9 vs 45.4%, P < 0.002), morphologically abnormal heads (7.3 vs 22.0%, P < 0.0001), seminiferous tubule diameter (183.4 vs 176.3 µm, P < 0.004) and altered elongated spermatids (2.2 vs 15.9, P < 0.001). Increasing O2 (from 13 to 95%) affected morphologically abnormal heads (15.4, 10.8 and 17.6%, respectively; P < 0.03), seminiferous tubule diameter (175.7, 185.6 and 178.4 µm, P < 0.003) and total altered spermatids (8.3, 3.3 and 15.2, P < 0.05). Our hypothesis was not supported; hypoxia did not replicate effects of hyperthermia with regards to reducing number and quality of sperm produced and hyperoxia did not mitigate effects of hyperthermia. We concluded that hyperthermia per se and not secondary hypoxia was the fundamental cause of heat-induced effects on spermatogenesis and sperm. These findings are of interest to develop evidence-based efforts to mitigate effects of testicular hyperthermia, as efforts should be focused on hyperthermia per se and not on hyperthermia-induced hypoxia.

Antler velvet is thicker in adult than in yearling pampas deer (Ozotoceros bezoarticus): a histological study.

BACKGROUND: Antlers are lined by soft velvet tissue during antler growth. Later, the velvet is shed before rut onset. There are no detailed histological descriptions of the growing velvet, nor whether the velvet changes according to stag age. Our aims were to: 1) describe the basic histology of pampas deer antler velvet from adult and yearling males; and 2) determine the influence of age and time of antler growth on velvet's tissues morphometry. MATERIALS AND METHODS: Samples were collected from 10 stags allocated in two groups, either adult (3-5 years old, n = 5) or yearling males (2 years old, n = 5). The day of antler cast was recorded for each animal. In spring, the stags were anaesthetised and velvet samples were collected from the third tine's distal end. Samples were described qualitatively and a restricted morphometrical analysis of the antler velvet was performed. RESULTS: The number of keratinocyte layers and the thicknesses of: total epidermis, corneum, intermediate and basale epidermal strata, total dermis, superficial and deep dermis were determined. Age and days after antler casting positively influenced in conjunction epidermal thickness (p = 0.037), and tended to influence both stratum intermedium (p = 0.076) and stratum corneum (p = 0.1) thicknesses. Age influenced stratum corneum thickness (p = 0.04). The pampas deer antler velvet lacked both sweat glands and arrector pili muscles. CONCLUSIONS: The deep dermis was densely irrigated but displayed abundant and well developed collagen bundles. Both total epidermal and stratum corneum thicknesses related positively to the age of the animals but were not to the time since antler cast.

Collagen and matrix metalloproteinase-2 and -9 in the ewe cervix during the estrous cycle.

The cervical collagen remodeling during the estrous cycle of the ewe was examined. The collagen concentration determined by a hydroxyproline assay and the area occupied by collagen fibers (%C), determined by van Gieson staining, were assessed in the cranial and caudal cervix of Corriedale ewes on Days 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (defined as Day 0). In addition, the gelatinase activity by in situ and SDS-PAGE gelatin zymographies and matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9, respectively) expression by immunohistochemistry were determined. The collagen concentration and %C were lowest on Day 1 of the estrous cycle (P < 0.04), when MMP-2 activity was highest (P < 0.006) and the ratio of activated to latent MMP-2 trend to be highest (P = 0.0819). The MMP-2 activity was detected in 73% of the homogenized cervical samples, and its expression was mainly detected in active fibroblasts. By contrast, the MMP-9 activity was detected in 9% of the samples, and its scarce expression was associated with plasmocytes, macrophages, and lymphocytes. Matrix metalloproteinase-2 expression was maximal on Day 1 in the cranial cervix and on Day 13 in the caudal cervix and was lower in the cranial than in the caudal cervix (P < 0.0001). This time-dependent increase in MMP-2 expression that differed between the cranial and caudal cervix may reflect their different physiological roles. The decrease in the collagen content and increase in fibroblast MMP-2 activity in sheep cervix on Day 1 of the estrous cycle suggests that cervical dilation at estrus is due to the occurrence of collagen fiber degradation modulated by changes in periovulatory hormone levels.

The effect of autologous activated platelet rich plasma (AA-PRP) injection on pattern hair loss: clinical and histomorphometric evaluation.

To investigate the safety and clinical efficacy of AA-PRP injections for pattern hair loss. AA-PRP, prepared from a small volume of blood, was injected on half of the selected patients' scalps with pattern hair loss. The other half was treated with placebo. Three treatments were given for each patient, with intervals of 1 month. The endpoints were hair re-growth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki-67 evaluation. At the end of the 3 cycles of treatment, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 18.0 hairs in the target area, and a mean increase in total hair density of 27.7 ( number of hairs/cm(2)) compared with baseline values. Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles two weeks after the last AA-PRP treatment compared to baseline value (P < 0.05). We also observed an increase of Ki67(+) keratinocytes of epidermis and of hair follicular bulge cells and a slight increase of small blood vessels around hair follicles in the treated skin compared to baseline (P < 0.05).

Cervical changes in estrogen receptor alpha, oxytocin receptor, LH receptor, and cyclooxygenase-2 depending on the histologic compartment, longitudinal axis, and day of the ovine estrous cycle.

The aim was to investigate the histologic distribution of estrogen receptor α (ERα), oxytocin receptor (OxR), LH receptor (LHR), and cyclooxygenase-2 (COX-2) in the cervix of the ewe during the estrous cycle. Immunohistochemistry was performed in the cranial and caudal cervix of Corriedale ewes on Day 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (Day 0). The ERα proportional score (%ERα nuclei) was lower in the cranial cervix than in the caudal cervix, whereas the OxR and COX-2 immunostaining areas (%areas) were greater in the cranial cervix than in the caudal cervix (P < 0.04). The %ERα nuclei decreased from Days 1 to 13 in luminal epithelia, but increased from Days 1 to 6 or remained unchanged in stromata (P < 0.003). The %OxR area was higher on Day 6 than on Days 1 and 13 in the superficial glandular epithelium, and increased from Days 1 to 13 in the deep glandular epithelium (P < 0.04). The %LHR area increased during the estrous cycle in luminal epithelia and fold stroma (P < 0.004). The %COX-2 area was restricted to epithelia, and it was lower on Day 1 than on Days 6 and 13 in luminal epithelia (P < 0.05). Differences in ERα, OxR, LHR, and COX-2 between cranial and caudal cervical zones indicate different physiological functions, and their cyclic variations in the cervical epithelia, in contrast to little or no variations in the stroma, suggest a hormone-responsive driving role of epithelia in cervical function.

Melanin concentrating hormone (MCH) in the cerebrospinal fluid of ewes during spontaneous oestrous cycles and ram effect induced follicular phases.

The melanin-concentrating hormone (MCH) is a neuropeptide synthesized by neurons of the lateral hypothalamus and incerto-hypothalamic area that project throughout the central nervous system. The aims of the present report were: (1) to determine if MCH levels in cerebrospinal fluid (CSF) of ewes vary between the mid-luteal and the oestrous phase of spontaneous oestrous cycles; and (2) to study if MCH levels in CSF of ewes vary acutely during the follicular phase induced with the ram effect in anoestrous ewes. In the first experiment, CSF was collected from 8 adult ewes during spontaneous oestrous and during the mid-luteal phase (8-10 days after natural oestrus). In the second experiment, performed during the mid non-breeding season, a follicular phase was induced with the ram effect. After isolating a group of 16 ewes from rams, CSF was obtained from 5 of such ewes (control group). Three rams were joined with the ewes, and samples were obtained 12h (n=6) and 24h (n=5) later. In Experiment 1, there were no differences in MCH concentrations in CSF measured during the mid-luteal phase and spontaneous oestrus (0.14 ± 0.04 vs. 0.16 ± 0.05 ng/mL respectively). In Experiment 2, MCH concentrations tended to increase 12h after rams introduction (0.15 ± 0.08 vs. 0.35 ± 0.21 ng/mL, P=0.08), and increased significantly 24h after rams introduction (0.37 ± 0.15 ng/mL, P=0.02). We concluded that MCH concentration measured in the CSF from ewes increased markedly during the response to the ram effect but not during the natural oestrous cycle of ewes.

Rapid increase of carbapenemase-producing Klebsiella pneumoniae strains in a large Italian hospital: surveillance period 1 March - 30 September 2010.

The first case of carbapenemase-producing Enterobacteriaceae in Italy was reported in 2009. We performed a study over a period of seven months in 2010 to survey the circulation of Klebsiella pneumoniae carbapenemases (KPC) ina 1,500-bed university hospital in northern Italy and report the presence and rapid increase of these multidrug-resistant bacteria. The results raise a major concern about these pathogens and demonstrate the urgent need for infection control and antibiotic stewardship programmes.

Undernutrition during foetal to prepubertal life affects aquaporin 9 but not aquaporins 1 and 2 expression in the male genital tract of adult rats.

Expression of aquaporin water channels (AQPs) in the male excurrent ducts, is of major importance for local water movements. To study the influence of pre- and postnatal undernutrition on AQP-expression in the adult male genital tract, 4 pregnant female rats were fed ad libitum (control group) and 4 with 33.5% of gestational feed requirements (underfed group). Feeding restriction of underfed group pups continued up to weaning (25 days of age), then all pups were fed ad libitum until slaughtered at 100 days of age. Epididymides were sampled and processed for aquaporin immunohistochemistry. Expression of AQP1 was similar either in the control and underfed groups of rats, strongly evidenced at the apical and lateral plasma membrane of the efferent ducts non-ciliated cells, in the smooth muscle cells surrounding epididymal duct and in blood vessel endothelium throughout the epididymis. AQP2-immunoreactivity was present in the corpus and cauda regions, strongly expressed in the principal cells of both groups of rats. In contrast, AQP9 expression was modified by early life undernourishment, as it was weakly evidenced at the microvilli in the principal cells and strongly diminished or completely lacked in the clear cells of the cauda, in underfed group epididymides. Since it is known that clear cells are involved in luminal fluid acidification, this function might be altered in adult animals, which were underfed during early life.

Undernutrition during foetal and post-natal life affects testicular structure and reduces the number of Sertoli cells in the adult rat.

To test whether undernutrition during foetal to pre-pubertal life would have long lasting effects on testicular histology in adult male offspring, eleven adult Sprague-Dawley pregnant rats were divided into two groups: Control group, n = 4, fed ad libitum, during gestation and lactation (until 25 day post-partum). Underfed group pregnant females (n = 7) were kept in cages where only dams had access to food (standard rat chow, 33.5% of ad libitum intake of Control group pregnant dams). After parturition, litters were adjusted to either 14 (Underfed group) or eight (Control group) pups. Mothers were weighed weekly. At 25 day of age pups were weaned, housed at four animals per cage, fed ad libitum and weighed weekly until euthanized at 100 day of age. Testes were processed for standard histology and morphometrical evaluation. At weaning, mother weight was lower in underfed than in Control group (mean +/- SD): 214.1 +/- 26.2 g vs 361.9 +/- 33.1 g. Body weight at 100 days of age (254 +/- 26.9 g vs 342.4 +/- 10.2 g, p

Histomorphology of prepuberal ovaries in the South American fur seal (Arctocephalus australis Zimmerman, 1783).

The South American fur seal reproductive histophysiology is scarcely described. This study provides a histological description of prepuberal South American fur seal (Arctocephalus australis) ovaries as well as three-dimensional reconstructions of subcapsular crypts and primordial follicles. Ovaries from fresh dead animals were processed for histology and sliced into serial sections. A portion of the superficial cortex was photographed, and the images were processed using BioVis3d software in order to generate 3-dimensional reconstructions. A. australis prepuberal ovaries conform to the basic structure of pinnipedian species, with a subcapsular crypts system made up of interconnecting cisternae and tubules with multiple openings to the surface. Generally, the primordial follicles were arranged in a monolayer beneath the tunica albuginea and were closely associated with subcapsular crypts. The large number of interstitial cells distributed throughout the cortex was the main histological feature in comparison with previous reports in other seals. Three-dimensional reconstructions modelled the subcapsular crypts microarchitecture and showed the close spatial relationship between the crypts and the primordial follicles. Despite the fact that the general ovarian histological structure was similar to that of other pinnipeds, the large number of interstitial cells is a distinctive feature that raises the question about the origin and function in A. australis with regard to the steroidogenic activity reported in other seal species.

Gross anatomy of the intestine and its mesentery in the nutria (Myocastor coypus).

The intestines and mesentery of the nutria (Myocastor coypus) have not been fully described. In the present study 30 adult nutrias were studied using gross dissection. The small intestine was divided into the duodenum, jejunum and ileum as usual. The duodenum started at the pylorus with a cranial portion, which dilated forming a duodenal ampulla. The ileum was located within the concavity of the caecum and attached to the coiled caecum by means of the iliocaecal fold. The ascending colon had two ansae, one proximal and one distal. The proximal ansa was fixed to the caecum by the caecocolic fold. The base of the caecum and a short proximal part of the ascending colon belonging to the proximal ansa were attached to the mesoduodenum descendens. The distal ansa of the ascending colon had a proximal part which was sacculated and a distal part which was smooth. The two parts of the distal ansa of the ascending colon were parallel and joined by a flexure of variable localisation. The smooth part of the distal ansa of the ascending colon was attached to the initial portion of the descending colon by a peritoneal fold. The short transverse colon was directly attached to the mesoduodenum and greater omentum. In conclusion, we have described the anatomy of the intestines of the nutria and its mesentery in detail, and provided a nomenclature list adapted to the Nomina Anatomica Veterinaria.

Effects of pre-natal glucocorticoids on testicular development in sheep.

We tested the hypothesis that acute pre-natal exposure to high levels of synthetic glucocorticoid (betamethasone) would alter fetal testicular development through actions on gonadal glucocorticoid receptors (GRs). Pregnant Merino ewes bearing singleton male fetuses (n = 24) were allocated randomly among four equal groups to be injected intramuscularly with saline or betamethasone (0.5 mg/kg) either on day 109 of gestation or on both day 109 and day 116 of gestation. Fetal testes were collected at post-mortem, 5 days after each treatment. The volume of interstitial tissue and the volume, length and diameter of the sex cords were measured, and Sertoli cells and gonocytes were counted. For cord volume and interstitial tissue volume, control testes demonstrated maturational changes as fetal age advanced from 109 to 116 days of gestation. For that period, the single injection of betamethasone significantly reduced Leydig cell proliferation (P < 0.05), but had no effect on Sertoli cell numbers. Immunohistochemistry was used to localize GR and proliferating cell nuclear antigen in testicular cells. GR immunoexpression in Leydig cells was higher in fetuses exposed to betamethasone at 109 days of gestation than in control fetuses. Sertoli cells showed low levels of GR. It was concluded that, during mid-gestation, a brief period of glucocorticoid treatment could affect testicular development in male sheep fetuses. The mechanism probably involves direct effects on Leydig cells, as these cells express extra-GR in response to the treatment. Sertoli cells seem to produce less GR than Leydig cells, perhaps explaining their lack of response to betamethasone. These outcomes may have important implications for future fertility in male offspring.

No change detected in body weight, scrotal circumference, semen characteristics and sexual behaviour during the development of prepubertal Milchschaf lambs after weekly administration of eCG.

To study the effects of equine chorionic gonadotropin (eCG) on pubertal development, 38 Milchschaf spring born male lambs fathered by the same ram and grazing over native pasture as a single mob during all the experiment were divided into three groups as follows: group 100 (100 IU of eCG weekly i.m., n = 11), group 400 (400 IU of eCG weekly i.m., n = 12) and group 0 (controls, n = 15). Lambs were weighed and scrotal circumference was registered every 2 weeks since birth until 170 days of age (end of experiment). On days 125 and 167 semen was collected using an electroejaculator. Semen volume and concentration, mass and individual sperm motility (scale 0 to 5) and total number of spermatozoa in the ejaculate were recorded. The sexual behaviour of the lambs was evaluated twice, on days 127 and 170 in a pen test with oestrous ewes. There were no significant effects of treatment on body weight or scrotal circumference, semen characteristics or sexual behaviour. At least in the administration regimens tested, eCG treatment has no effect on prepubertal reproductive development of male lambs.

Histology of lamb epididymal development.

To describe the distribution of the histological regions and their morphometry during epididymal development, 10 Corriedale lambs were castrated monthly from 90 to 180 days of age (n = 24), and their testes and epididymides were weighed. All animals were weighed monthly. Epididymides were divided into caput, corpus and cauda, and cut sagitally so that sections included all the length of the organ. The diameter of the epididymal duct, the smooth muscle depth and the epididymal epithelium height were measured. The quantitative histology of the ovine epididymal development was described. Epididymal development advanced from caput to cauda. The distribution of the histological regions varied according to epididymal weight. Transient histological regions were found during epididymal development. The present results indicate a new way of epididymal development in sheep, which courses from caput to cauda with transient histological regions appearing, varying in location and disappearing during ovine epididymis development.

Androgen Receptor Distribution, PAS and Alcyan Blue Reaction in the Vomeronasal Organ and the Nasal Septum Mucosa of the Developing Male Rat / Distribución del Receptor de Andrógeno, Positividad a PAS y Alcyan Blue en el Órgano Vomeronasal y la Mucosa del Tabique Nasal Durante el Desarrollo de la Rata Macho

The vomeronasal organ (VNO) is a tubular chemoreceptory organ which detects environmental pheromones and is essential for mammalian normal reproductive activity. A sensitive chemoreceptory neuroepithelium lines the concave VNO wall and the opposite, convex wall is lined by a seudostratified, receptor-free epithelium. The secretion of the Jacobson glands (JG) -tubuloacinary glands lying in the lamina propia of the VNO - is essential for pheromones contacting vomeronasal organ chemoreceptors. Tubuloacinary glands lying in the connective tissue of the nasal septum mucosa (Bowman glands), can be classified as ventral and dorsal, according to their location. Positivity to PAS and Alcyan blue reactions and androgen receptor immunolocalization was evaluated with a semiquantitative system (0,1, 2 or 3 crosses) in JG, ventral Bowman glands (VBG), dorsal Bowman glands (DBG), sensitive chemoreceptory neuroepithelium (Ne), receptor-free epithelium (RFE) and nasal septum respiratory epithelium (RE) histological slides of male rats at 5, 15, 25 and 35 days of age. The VBG and JG were intensely positive to PAS reaction since 5 days of age, and weakly positive to Alcyan blue reaction (AB) since 15 days of age, but not at 5 days of age. Both JG and VBG were strongly positive to androgen receptor immunolocalization at all ages studied (15, 25 and 35 days of age). DBG were always negative to both PAS and AB reactions. The NE and the RFE and nasal mucosa luminar epithelium were negative. To our knowledge, this is the first report of androgen receptor (AR) immunolocalization in the vomeronasal organ and the nasal septum mucosa. The present results also suggest an influence of androgens on the mechanism of pheromones contacting with the Ne of the VNO through regulation of the Jacobson glands secretion.

El órgano vomeronasal (VNO) es un órgano quimioreceptor, tubular, que detecta feromonas ambientales. Es esencial para la actividad reproductiva normal de los mamíferos. El VNO está formado por un neuroepitelio quimiosensible (pared cóncava, Ne) y un epitelio pseudoestratificado (epitelio libre de receptores: RFE) en la pared opuesta, convexa. La secreción de las glándulas tubuloacinares de Jacobson (JG), ubicadas en la lámina propia del VNO, son esenciales para que las feromonas entren en contacto con el Ne. Las glándulas tubuloacinares ubicadas en la mucosa del tabique nasal (glándulas del Bowman), se pueden clasificar como ventrales (VBG) y dorsales (DBG), según su localization. La positividad a las técnicas de PAS, Azul de Alcián (AB) e immunolocalization del receptor de andrógeno (AR), fueron evaluadas con un sistema semicuantitativo (0, 1, 2 o 3 cruces) en láminas histológicas de JG, VBG, DBG, Ne, RFE y del epitelio del tabique nasal (RE) en ratas macho de 5, 15, 25 y 35 días de edad. Las VBG y JG fueron intensamente positivas a la reacción de PAS desde los 5 días de edad y débilmente positivas a la reacción de AB desde los 15 días de edad, pero no a los 5 días de la edad. Las JG y VBG fueron fuertemente positivas a la immunolocalization del AR en las edades estudiadas (15, 25 y 35 días de edad). Las DBG fueron siempre negativas a las reacciones de PAS y AB. El NE, el RFE y el RE fueron negativos. Según nuestro conocimiento, éste es el primer informe de immunolocalization del AR en el VNO y la mucosa del tabique nasal. Los actuales resultados sugieren una influencia de los andrógenos en el mecanismo por el cual entran en contacto las feromonas y el Ne, a través de la regulación por andrógenos de la secreción de las JG.

Relationship between male-male and male-female sexual behavior in 5-6-month-old male lambs.

To characterize male-male sexual behavior during lamb development, to relate it with lamb body and testicular growth, and with sexual behavior toward estrual ewes, 40 Milchschaf male lambs, weaned at 45 days of age, were kept with ewes that were nursing younger lambs. Experimental lambs were weighed and scrotal circumference was measured every 2 weeks. Male-male sexual behavior was observed during 1-2 h every 2 weeks after birth until 7 months of age. Observations were recorded more intensively (3-4 h on five different days) for 2 weeks (5-6 months of age) as male-male sexual behavior increased during that period. Both mounting and mounted lambs were identified. An individual mounting index (MI) was calculated. To study male-female sexual behavior, lambs were individually located with two estrual ewes, and during 5 min the number of ano-genital sniffing, lateral approaches, mounts, and mounts with ejaculation were recorded. From those data, a libido index was also calculated. Male-male mounts (n=308) were observed. Courtship behavior was displayed in 25% of interactions; mounts were accepted in 72.1% of attempted mounts. Mounts without previous courtship were accepted more frequently than mounts with previous courtship (P=0.002). Lamb weight and scrotal circumference were not different according to MI groups. Lambs that mounted more times estrual ewes (first tertile) had greater (P=0.04) MI (0.61+/-0.10) than lambs with medium (0.27+/-0.09) and less (0.30+/-0.10) MI. The regression between MI and heterosexual libido index was r=0.33 (P<0.05). In summary, intensive male-male sexual activity during a short period of male lamb development was observed. There was a positive relationship between sexual behavior of male lambs towards other male lambs and towards estrual ewes.

Sex differences in oestrogen receptor levels in adrenal glands of sheep during the breeding season.

The concentrations of the oestrogen receptor (ER), and the mRNA levels of ERalpha, progesterone receptor (PR) and insulin-like growth factor I (IGF-I) were characterised in adrenal glands and uterine tissue of adult Corriedale sheep during the breeding season. The sheep were of different sex and gonadal status. Ewes had higher levels of cytosolic ER in the adrenals than the rams (mean+/-S.E.M.: 7.3+/-2.0 fmol/mg protein and 2.5+/-1.0 fmol/mg protein, respectively; P=0.0091) and gonadectomy increased ER (mean+/-S.E.M.: 2.9+/-1.2 fmol/mg protein and 8.6+/-2.3 fmol/mg protein, intact and gonadectomised sheep, respectively; P=0.0071). No differences could be observed in mRNA levels for ERalpha and IGF-I in the adrenal glands of all of the sheep. PR mRNA levels were reduced in ovariectomised ewes and enhanced in castrated rams (sex x gonadal status: P=0.009). PR mRNA levels tended to be higher in ewes in the follicular phase than in ovariectomised ewes and intact rams (P<0.1). All of the animals had positive nuclear staining for ERalpha in the adrenal cortex, but no differences were observed between the groups. In this study, we demonstrated the existence of ER in the adrenal gland of sheep and found varying sensitivity to oestrogens as the ER levels differed among sex and gonadal status. These findings indicate that oestrogens most likely affect steroidogenesis directly at the adrenal cortex and suggest that oestrogens are partly responsible for the sex differences in cortisol secretion in sheep.

Rab4 affects both recycling and degradative endosomal trafficking.

The small GTPases Rab4, Rab5 and Rab7 are endosomal proteins which play important roles in the regulation of various stages of endosomal trafficking. Rab4 and Rab5 have both been localized to early endosomes and have been shown to control recycling and endosomal fusion, respectively. Rab7, a marker of the late endosomal compartment, is involved in the regulation of the late endocytic pathway. Here, we compare the role of Rab4, Rab5 and Rab7 in early and late endosomal trafficking in HeLa cells monitoring ligand uptake, recycling and degradation. Expression of the Rab4 dominant negative mutant (Rab4AS22N) leads to a significant reduction in both recycling and degradation while, as expected, Rab7 mutants exclusively affect epidermal growth factor (EGF) and low density lipoprotein degradation. As also expected, expression of the dominant negative Rab5 mutant perturbs internalization kinetics and affects both recycling and degradation. Expression of Rab4WT and dominant positive mutant (Rab4AQ67L) changes dramatically the morphology of the transferrin compartment leading to the formation of membrane tubules. These transferrin positive tubules display swellings (varicosities) some of which are positive for early endosomal antigen-1 and contain EGF. We propose that the Rab4GTPase is important for the function of the early sorting endosomal compartment, affecting trafficking along both recycling and degradative pathways.