Age-Related Changes in the Testicular Morphophysiology of the Cane Rat (Thryonomys swinderianus).

This study evaluated age-related changes in the testicular morphophysiology of the cane rat (Thryonomys swinderianus) using histological, histochemical, and sex hormonal profile approaches. Twenty (20) pathogen-free male cane rats were used for the investigation. Cane rats were divided into four groups: prepubertal (≤4 months), pubertal (>4 ≤12 months), adult (>12 ≤30 months), and aged (>30 months) of 5 rats each. Blood was collected from the different cane rat groups and processed for sex serum hormonal levels. Testes were also excised and processed routinely for variations in histology, histochemistry (using Masson's trichrome [MT] and Periodic acid-Schiff [PAS]), and histomorphometric evaluations using GIMP2 software. Testosterone concentrations were significantly elevated (P < 0.05) in the prepubertal to adult, while there were no significant differences (P > 0.05) in this hormone between adult and aged. The concentrations of follicle-stimulating hormone (FSH) decreased significantly (P < 0.05) for prepubertal, pubertal, and adult, respectively. There were no significant differences (P > 0.05) between adult and aged for FSH and luteinizing hormone. Histologically, there were scanty interstitial cells, lack of patent lumen, and incomplete spermatogenetic cell series in prepubertal compared to other age groups. Testicular capsular (MT and PAS) staining intensity increased with age advancement, while in the parenchyma, remarkably high intensity was displayed by the pubertal compared to others. Seminiferous tubular and luminal diameters (LD) significantly (P < 0.05) increased with advancing age whereas epithelial height (EH) was markedly increased in pubertal relative to other groups. In conclusion, these sets of data have shown that reproductive activity is directly related to age and is at maximum in adult cane rat.

Nerve and Glial Cell Expressions in the Testes and Epididymides of Different Age Groups of Cane Rat (Thryonomys swinderianus).

PURPOSE: This study was conducted to examine the variations in the expressions of neuronal and glial cell markers in the testes and epididymides of different age groups of cane rat using histochemical and immunohistochemical techniques. METHOD: Thirty (32) healthy domesticated male cane rats were used for this investigation. The rats were divided into four groups (prepubertal [≤4 months], pubertal (>4 ≤12 months), adult (>12 ≤30 months), and aged (>30 months)] of 8 animals each. Subsequent to anesthesia and intracardiac perfusion of the rats with 10% buffered formalin, testes were harvested and preliminary assessment of nervous and glial structures was determined using the Golgi technique. Specific immunolocalization was done using the anti-neurofilament (NF-20) and anti-glial fibrillary acid protein (GFAP) for the expressions of neuronal and astrocyte-like cells, respectively. RESULT: Neuronal and astrocyte-like structures as revealed by the Golgi procedure were demonstrated in the tunica albuginea and interstitium of the testes as well as in the periductal muscle coat and epididymal interstitium of the caput down to the caudal segments. Golgi signal intensities of the expressions in both testes and epididymides increased with age advancement. Immunolocalization of the nerve structures and glial cells tallied with the Golgi results. However, NF signal intensity was significantly higher in the adult relative to others. Similarly, GFAP signal intensity increased with age increment. CONCLUSION: This study has shown that the variation in the expression of neuronal and glial cells in the testis and epididymis of the cane rat could be associated with increased reproductive reproductive activity.

Chronic exposure of adult male Wistar rats to bisphenol A causes testicular oxidative stress: Role of gallic acid.

OBJECTIVES: Bisphenol A (BPA) has been reported that among other male reproductive dys-functions, it can cause marked estrogenic effects including alteration in serum hormones as well as testicular lesions in exposed animals. This work sought to study the role of gallic acid (GA), a known antioxidant, on the BPA-induced testicular oxidative stress in adult male Wistar rats using serum hormone analysis, histopathology, and biochemical assays. METHODS: Adult male rats were divided into four groups (n=10) including control (0.2 ml of corn oil), GA (20 mg/kg/day), BPA (10 mg/kg/day), BPA+GA (BPA, 10 mg/kg/day + GA, 20 mg/kg/day). All medications were given by oral gavage for 45 consecutive days. The body and testicular weights were measured. Blood and organ samples were collected for the serum hormonal assay: testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL), and tissue biochemistry analysis: superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-S-transferase (GST), malondialdehyde (MDA), hydrogen peroxide (H2O2), respectively. RESULTS: The BPA-treated rats showed significant reduction in the gonadosomatic index. BPA also caused significant decrease in the levels of the serum testosterone and prolactin. Furthermore, BPA induced testicular oxidative stress by decreasing the activities of antioxidant enzymes and increasing reactive oxygen species. However, co-treatment with GA protected against these alterations. CONCLUSION: Findings from the present study confirmed the previously reported data and show that the ability of GA, as a potent antioxidant, may protect against BPA-induced alterations in the male reproductive function. Hence, GA protects against testicular oxidative stress in adult male Wistar rats following chronic exposure to BPA.

Relationship between Body Mass Index (BMI) and testicular and hormonal parameters of sexually active male greater cane rats (Thryonomys swinderianus).

The current upsurge in intensive farming practices of greater cane rat has not only lead to higher growth rate but is accompanied by increased fat deposition especially in the males. This study attempts to characterize one of the most commonly used fat estimation parameter, the body mass index (BMI) as well as evaluates its relationship with testicular and hormonal parameters in seventy-two sexually active male cane rats over a period of one year. Six animals, kidded and raised in a farm, with known ages were used each month. The experimental protocols entail body measurements of weight, height and length; histology; orchidometry; and hormonal immunoassay of testosterone, estradiol, progesterone, LH and FSH using their various kits. The mean values of the body mass (BMI) and Lee (LI) indices of male greater cane rats were 1.18±0.20g/cm2 and 0.30±0.02g/cm respectively with the testicular histology indicating normal spermatogenesis. BMI/LI, both of which followed the same pattern, neither correlate with testicular parameters nor with serum testosterone, progesterone, LH and FSH concentrations but had low correlations with serum estradiol concentration (r2 = 0. 2; p = 0.0023). So, these relationships may provide clue on obesity and its effect on reproductive performance and strengthened the possibility of the characterized BMI/LI as obesity marker for breeding selection in male cane rat.

Maternal exposure to environmentally relevant doses of bisphenol A causes reproductive dysfunction in F1 adult male rats: protective role of melatonin.

This study investigated the protective effects of melatonin (MLT), a potent antioxidant, in male Wistar rats exposed to environmentally relevant doses of bisphenol A (BPA) in utero. Pregnant Wistar rats were randomly assigned into five groups. Group 1 (control) received 0.2 mL 1% dimethyl sulfoxide (DMSO)/99% canola oil as vehicle; group 2 received BPA at 25 µg/kg/day; group 3 received BPA at 250 µg/kg/day; group 4 received BPA at 25 µg/kg/day with concurrent MLT 1 mg/kg/day while group 5 received BPA at 250 µg/kg/day with concurrent MLT 1 mg/kg/day. Treatments were by gavage from gestational day (GD) 10-21. The BPA-treated rats showed dose-dependent significant reduction in body weight, gonosomatic index, sperm motility, livability and count. Also, BPA caused significant reduction in the levels of serum testosterone and luteinizing hormone while it caused significant increases in the levels of follicle stimulating hormone as well as estradiol. Furthermore, BPA induced testicular oxidative stress including significant decreases in the activities of testicular SOD, GSH and GPx as well as GST, increasing the levels of testicular MDA and H2O2. It further induced interstitial necrosis and germinal cell degeneration in the testis with a subsequent diminution of the tubular and luminal diameter. However, co-treatment with MLT offered protection against testicular damage induced by BPA. Melatonin is likely to protect against alterations of the male reproductive system caused by BPA through a direct action on the mechanism of anti-oxidants as well as through the inhibition of necrosis.

Melatonin attenuates bisphenol A-induced toxicity of the adrenal gland of Wistar rats.

This study investigated the role of melatonin (MLT) on adrenal gland toxicity induced by bisphenol A (BPA). Adult male rats were divided into four groups of seven animals each: Group I (control) received oral 0.2 ml canola oil; group II received intra-peritoneal 10 mg/kg BW/day MLT; and group III received oral BPA (10 mg/kg BW/day). Group IV rats were treated with same dose of BPA as group III with a concomitant intra-peritoneal 10 mg/kg BW/day MLT. All treatments lasted for 14 days. BPA significantly increased (P < 0.05) adrenal index, circulating levels of corticosterone and adrenocorticotropic hormone (ACTH) in the rats. BPA caused marked vascular congestion, hyperplasia, cellular distortion, increased lipid peroxidation, decreased antioxidant enzymes, and decreased expression of αSmooth muscle actin as well as vimentin proteins. The concomitant treatment with MLT ameliorated these BPA-induced alterations. It is likely that melatonin attenuates BPA-induced alterations of the adrenal gland of rats through the antioxidant defense mechanism.

Melatonin ameliorates bisphenol A-induced perturbations of the prostate gland of adult Wistar rats.

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) that has been demonstrated to induce alterations in reproductive organs while melatonin (ML), an antioxidant, present in plants and animals, is capable of protecting against EDC-induced alterations. Adult male Wistar rats (average weight, 240 + 10 g) were divided into four groups of ten animals each: Rats in group I (control) received oral 0.2 ml 1% dimethyl sulfoxide (DMSO)/99% canola oil as vehicle; group II received intra-peritoneal 10 mg/kg BW/day ML. Group III received oral BPA dissolved in DMSO and solubilized in canola oil at 10 mg/kg BW/day. Group IV were treated with same dose of BPA as group III with a concomitant intra-peritoneal 10 mg/kg BW/day ML. All treatments lasted for 14 days. BPA significantly increased the prostatic index of the rats while ML ameliorated it. BPA significantly increased serum levels of estrogen as well as prostate-specific antigen but decreased serum testosterone in the rats while concomitant treatment with ML ameliorated these alterations. Also, BPA caused vascular congestion, hyperplasia (functional, reactive and atypical) of prostatic epithelium as well as tubular atrophy the rats while ML attenuated the observed lesions. Decreased localization of αSmooth muscle actin, vimentin and S100 proteins were observed in the BPA-treated rats while these decreases were ameliorated by ML. The present study has shown that sub-acute oral administration of BPA induced alterations in prostatic index, serum hormone levels, down-regulated protein localization and induced morphological lesions of the prostate gland in rats while concomitant treatment with intra-peritoneal ML ameliorated these conditions. Hence, low dose of ML can protect against BPA-induced toxicity of the prostate gland of rats.

Histology and histochemistry of the adrenal gland African giant rat (Cricetomys gambianus, Waterhouse) / Histología e histoquímica de la glándula adrenal de la rata africana gigante (Cricetomys gambianus, Waterhouse)

The histology and histochemistry of the adrenal gland of the African giant rat, AGR (Cricetomys gambianus Waterhouse) was carried out using ten adult male rats with the knowledge of providing information which could be helpful in an improved knowledge of the structure and function of the gland. The adrenal gland of the African giant rat has a distinct cortex and medulla surrounded by a thin rim of capsule. The adrenal cortex has three zones which are basically the zona glomerulosa, zona fasiculata and zona reticularis with the absence of zona intermedia. The zona glomerulosa contains polyhedral cells which form irregular clusters or cords while the zona fasiculata had radial cells of cuboidal or polyhedral shape. The cells of zona reticularis are similar to those of the zona fasiculata and in addition contain small cells as irregular cords and clusters. The cells of the adrenal medulla are composed of irregular epithelioid cells arranged in rounded groups or short cords and are mostly columnar or polyhedral chromaffin cells which are separated by sinusoids. The adrenal capsule, cortex and medulla were Periodic Acid-Schiff-positive.The adrenal capsule and adrenal medulla was Masson Trichrome-positive unlike the zona fasiculata and zona reticularis. The adrenal capsule and zona glomerulosa were Verhoeff-positive unlike the other zones of the gland. In conclusion the histology of the adrenal gland of the AGR is similar to those of other mammals with a few exceptions, the entire gland is rich in carbohydrate while the capsule and by extension, the outermost portion of the cortex are rich in collagen and elastic fibers. The outcome of this research provides information needed in the better improved understanding of the structure and function of the adrenal gland of the animal.

La histología y la histoquímica de la glándula suprarrenal de la rata africana gigante (Cricetomys gambianus Waterhouse) (RGA) se llevó a cabo utilizando diez ratas macho adultas con el objetivo de proporcionar información que podría ser útil para un mejor conocimiento de la estructura y función de la glándula. La glándula suprarrenal de la rata africana gigante tiene una corteza y una médula distintas, rodeadas por un borde delgado de la cápsula. La corteza suprarrenal tiene tres zonas que son básicamente: zona glomerulosa, zona fasciculata y zona reticular, con ausencia de zona intermedia. La zona glomerulosa contiene células poliédricas que forman racimos irregulares o cuerdas, mientras que la zona fasciculata tenía células radiales de forma cuboidal o poliédrica. Las células de la zona reticular son similares a las de la zona fasciculata y además contienen células pequeñas como cordones irregulares y racimos. Las células de la médula suprarrenal están compuestas por células epitelioides irregulares dispuestas en grupos redondeados o cuerdas cortas y son en su mayoría células cromafines columnares o poliédricas, que están separadas por sinusoides. La cápsula suprarrenal y la médula suprarrenal fueron positivas con tricrómico de Masson, a diferencia de la zona fasciculata y la zona reticular. La cápsula suprarrenal y la zona glomerulosa fueron positivas a Verhoeff, a diferencia de las otras zonas de la glándula. En conclusión, la histología de la glándula suprarrenal de la RGA es similar a la de otros mamíferos con algunas excepciones; toda la glándula es rica en carbohidratos, mientras que la cápsula y por extensión, la parte más externa de la corteza, son ricas en colágeno y fibras elásticas. El resultado de esta investigación proporciona información necesaria para mejorar la comprensión de la estructura y función de la glándula suprarrenal del animal.

Ultrastructural features of ovary of the female African giant rat (Cricetomys gambianus, Waterhouse) during oestrous cycle / Características ultraestructurales durante el ciclo estral del ovario de rata gigante africana (Cricetomys gambianus, Waterhouse)

Fine structures of the ovary during the oestrous cycle in African giant rats (Cricetomys gambianus Waterhouse) were described in the present study. Ultrastructural features of the germinal epithelium and the medullar of the ovary were similar at different stages of the oestrous cycle. During mid proestrus, there was disorganization of the inner layer of the granulosa cells of secondary follicles to form the antrum. At late proestrus/early estrus, antrum formation had advanced and there was evidence of reorganization of granulosa cells. Fine structures of the ovary during mid estrus include follicles with variably shaped mitochondria, profiles of Golgi complexes and dense concentration of ribosomes. The theca interna shared similar ultrastructure with the granulosa cells containing, in addition, lipid droplets and smooth endoplasmic reticulum. Cellular ultrastructure observed during mid metestrus showed commencement of differentiation of corpus luteum. At mid diestrus, the general ultrastructural architecture of the ovarian follicles showed disorganized cellular contents and corpus luteum was recognized with conspicuous depolarization of the basement membrane originally separating granulosa cells from the theca. At late diestrus/early proestrus, granulosa cells displayed numerous mitochondria of variable sizes and shapes. Ribosomes were evenly distributed throughout the cytoplasm while electron lucid vesicles were sparsely distributed. The results of this study showed that fine structural changes in the ovary of the giant rat during the oestrous cycle are similar to those of laboratory rodents.

El presente estudio describe las estructuras específicas del ovario durante el ciclo estral en ratas gigantes africanas (Cricetomys gambianus Waterhouse). Las características ultraestructurales del epitelio germinal y medular del ovario fueron similares durante las diferentes etapas del ciclo estral. A mediados del período proestro, se observó una desorganización de la capa interna de las células de la granulosa, de folículos secundarios para formar el antro folicular. A fines del proestro/ciclo estral temprano, se observó un avance de la formación del antro y fue posible evidenciar la reorganización de las células de la granulosa. Las estructuras finas del ovario durante mediados del ciclo estral incluyen folículos con mitocondrias en forma variable, perfiles de complejos de Golgi y densa concentración de ribosomas. La teca interna compartida, evidenció ultraestructura similar a las células de la granulosa, que además contienen las gotas de lípidos y retículo endoplásmico liso. La ultraestructura celular que observamos durante mediados del ciclo estral mostró el comienzo de la diferenciación del cuerpo lúteo. A mediados del ciclo diestro, la formación ultraestructural de los folículos mostró un contenido celular desorganizado y se observó el cuerpo lúteo con despolarización de la membrana basal que separa las células de la granulosa de teca. Al término del período diestro al comienzo del proestro, se observaron numerosas mitocondrias de diversos tamaños y formas en las células de la granulosa. En el citoplasma, los ribosomas se distribuyeron de manera uniforme, mientras que los electrones lúcidos de vesículas estaba escasamente distribuidas. Los resultados de este estudio indican que los cambios finos estructurales en el ovario de la rata gigante durante el ciclo estral son similares a los de los roedores de laboratorio.

Characterization of the uterus and mammary glands of the female African giant rats (Cricetomys gambianus, Waterhouse) in Nigeria / Caracterización del útero y glándulas mamarias de la rata africana gigante hembra (Cricetomys gambianus, Waterhouse) en Nigeria

Morphology of the uterus and mammary glands were studied in sexually matured female African giant rat. The uterus was identified as being duplex, having two separate uterine horns and two cervices. The two cervices were partially fused and separated by a mid-saggital septum. Their thick musculatures projected caudally into the vagina as the portio vaginalis uteri. The results also showed that eight mammary glands, distributed along the lateral aspects of thoracic and inguinal regions, were present. The thoracic and the inguinal regions had four mammary glands each and were arranged in two pairs of cranial and caudal rows. These findings fill some gaps created by the dearth of information on the reproductive biology of the female African giant rat.

La morfología del útero y las glándulas mamarias fueron estudiadas en ratas Africanas gigantes sexualmente maduras. El útero fue identificado como doble, teniendo dos cuernos uterinos separados y dos cervix. Los dos cervix estaban parcialmente fusionados y separados por un tabique mediano sagital. Su grosor muscular se proyecta caudalmente en la vagina como la porción vaginal del cuello uterino. Los resultados también mostraron que ocho glándulas mamarias, distribuidas a lo largo de las zonas laterales de tórax y la región inguinal estaban presentes. La región torácica e inguinal tenía cuatro glándulas mamarias en cada lado y se organizaron en dos pares de filas craneales y caudales. Estos hallazgos completan algunas lagunas creadas por la escasez de información sobre la biología reproductiva de la rata gigante Africana hembra.

Caudofrontal depression on the cornual end of the temporal line of the skull of goat breeds in Nigeria / Depresión Caudofrontal en el Final del Cuerno de la Línea Temporal del Cráneo de una Raza de Cabra en Nigeria

Un estudio comparativo fue efectuado en 65 cráneos obtenidos de tres diferentes razas de cabras en Nigeria: Red Sokoto, Sahel y West African Dwarf. Una única depresión fue encontrada en el final del cuerno de la línea temporal del cráneo medial, al límite de la porción media con la caudal de la órbita y dorsal a la porción lateral de la sutura frontoparietal. La depresión fue encontrada en todas las cabras estudiadas, en ambo sexos, en el lado lateral de ambos procesos corneales de los huesos frontales. La medidas (profundidad, altura y ancho) de la depresión no tenían relación con edad o sexo de las razas de cabras. La literatura no aportó ninguna información de la depresión en el cráneo de la cabra. Por lo tanto, proponemos denominarla depresión caudofrontal.

A comparative study of skull types was done using 65 skulls obtained from three different goat breeds in Nigeria namely; Red Sokoto, Sahel and West African Dwarf. A unique depression was consistently found at the cornual end of the temporal line of the skull medial to the middle portion of the caudal boundary of the orbit and dorsal to the lateral portion of the parietofrontal suture. The depression was found in all the breeds studied, and in both sexes on the lateral sides of both cornual processes of the frontal bones. The features (depth, height and width) of the depression were found to vary without regard to either sex or breed. A search of the literature did not yield any information on this depression in the skull of the goat. Consequently, we venture to name this depression, the caudofrontal depression.

Morphometric Investigation of the Brainof West African Dwarf Sheep in Nigeria / Investigación Morfométrica del Encéfalo de la Oveja Enana del Oeste Africano en Nigeria

Morphometric studies were carried out on the brains of twenty West African Dwarf (WAD) sheep using frozen unfixed specimen. The mean brain weight was 69.14g, while the mean brain length and depth were 7.48cm and 4.17cm, respectively. The mean length of the cerebrum and cerebellum were 5.08cm and 2.27cm, respectively. The relative brain weight was 0.08% while the relative weight of the head was 0.8%. There was a significant difference (p < 0.05) in the weight of head, weight of brain, brain length and depth and in the relative brain weight of animals weighing 10kg and above, compared with those below this weight mark. The values of the first four parameters were higher while the fifth was lower. Animals aged one year and above, had significantly heavier body weights and longer cerebrum (p < 0.05), than those below this age mark, the latter however had significantly lower relative brain weight and also weight of brain to weight of head. The results obtained in this study will be useful in Comparative Neuroanatomy and as baseline research data in neuropathology, pharmacology, anaesthesiology and neurophysiology.

Se efectuó un estudio morfométrico en 20 encéfalos frescos, congelados de ovejas enanas del Oeste africano. El peso promedio del cerebro fue de 69.14g, mientras que el largo y la altura fueron de 7.48cm y 4.17cm, respectivamente. La longitud promedio del cerebro y cerebelo de 5.08cm y 2.27cm, respectivamente. El peso relativo del encéfalo fue 0,08%, mientras que el de la cabeza fue 0.8%. Hubo diferencias significativas (p< 0.05) en el peso de la cabeza, del encéfalo, longitud y altura del cerebro y en el peso relativo del cerebro de los animales de más de 10kg, si éstos son comparados con animales de menor peso. Los valores de los primeros cuatro parámetros fueron más altos, en cambio el quinto fue más bajo. Animales de un año de edad y más, tenían un cuerpo significativamente más pesado y un cerebro de mayor longitud (p < 0.05) que aquellos bajo esta edad. Sin embargo, en estos últimos fue significativo un peso relativo más bajo para el encéfalo y la cabeza.