Reproductive performance and weaning success in fur-chewing chinchillas (Chinchilla lanigera).

In captive chinchillas, one of the most challenging behavioral problems is the development of a stress-related abnormal repetitive behavior (ARB) known as "fur-chewing". We investigated whether there is a relationship between the severity of fur-chewing behavior and reproductive function in male and female chinchillas. Regardless of the severity of abnormal behavior, fur-chewing males did not show significant differences in seminal quality (sperm concentration, motility and viability; integrity of sperm membrane and acrosome) and the response to the process of semen collection (the number of stimuli needed to achieve ejaculation) when compared to those with normal behavior. Also, females showing normal or fur-chewing behavior presented similar reproductive performance in terms of number of litters per female per year and litter size. However, pup survival rate was lower (p=0.05) in fur-chewing females than in normal females. These results seem to be consistent with data suggesting non-significant effects of ARBs on reproductive performance.

Adrenal activity and anxiety-like behavior in fur-chewing chinchillas (Chinchilla lanigera).

Due to its complexity, in combination with a lack of scientific reports, fur-chewing became one of the most challenging behavioral problems common to captive chinchillas. In the last years, the hypothesis that fur-chewing is an abnormal repetitive behavior and that stress plays a role in its development and performance has arisen. Here, we investigated whether a relationship existed between the expression and intensity of fur-chewing behavior, elevated urinary cortisol excretion and anxiety-related behaviors. Specifically, we evaluated the following parameters in behaviorally normal and fur-chewing animals of both sexes: (1) mean concentrations of urinary cortisol metabolites and (2) anxiety-like behavior in an elevated plus-maze test. Urinary cortisol metabolites were higher only in females that expressed the most severe form of the fur-chewing behavior (P≤0.05). Likewise, only fur-chewing females exhibited increased (P≤0.05) anxiety-like behaviors associated with the elevated plus-maze test. Overall, these data provided additional evidence to support the concept that fur-chewing is a manifestation of physiological stress in chinchilla, and that a female sex bias exists in the development of this abnormal behavior.

[Obesity and male fertility]. / Impacto de la obesidad en la función reproductiva masculina.

Obesity and male infertility have increased in the last decades; therefore, a possible association between these pathologies has been explored. Studies inform that obesity may affect fertility through different mechanisms, which alltogether could exert erectile dysfunction and/or sperm quality impairment. These include: 1) hypothalamic-pituitary-testicular (HPG) axis malfunction: obese hormonal profile is characterized by reduction of testosterone, gonadotrophins, SHBG and/or inhibin B concentrations (marker of Sertoli cells function) and hyperestrogenemy (consequence of aromatase overactivity ascribed to adipose tissue increase); 2) increased release of adipose-derived hormones: leptin increase could be responsible for some of the alterations on the HPG axis and could also exert direct deleterious effects on Leydig cells physiology, spermatogenesis and sperm function; 3) proinflammatory adipokines augmentation, higher scrotal temperature (due to fat accumulation in areas surrounding testes) and endocrine disruptors accumulation in adiposites, all of these responsible for the increase in testes oxidative stress and 4) sleep apnea, frequent in obese patients, suppresses the nocturnal testosterone rise needed for normal spermatogenesis. Finally, although controversial, all the above mentioned factors could comprise gametes quality; i.e. decrease sperm density and motility and increase DNA fragmentation, probably disturbing spermatogenesis and/or epididymal function. In summary, although obesity may impair male fertility by some/all of the described mechanisms, the fact is that only a small proportion of obese men are infertile, probably those genetically predisposed or morbidly obese. Nevertheless, it is likely that because the incidence of obesity is growing, the number of men with reduced fertility will increase as well.

Overweight and seminal quality: a study of 794 patients.

OBJECTIVES: To evaluate sperm quality, levels of markers of epididymal and accessory gland function, and T in semen from men grouped according to their body mass index (BMI). DESIGN: Blind prospective study. SETTING: Andrology and reproduction laboratory in Cordoba, Argentina (2006-2007). PATIENT(S): Seven hundred ninety-four men. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): In semen samples, sperm quality (volume, density, motility, morphology, viability, hypoosmotic swell test, and nuclear maturity) and levels of neutral alpha-glucosidase, fructose, citric acid and T. RESULT(S): Multivariate analysis showed a negative association between BMI and motility, rapid motility and neutral alpha-glucosidase levels, and a positive association between BMI and seminal fructose levels. No associations were found among BMI and sperm concentration, the other parameters evaluated, or seminal T levels. CONCLUSION(S): Results found in our study support a deleterious effect of obesity on seminal quality, probably by alterations in the function of the epididymis (i.e., in epididymal maturation).

Developmental and neurobehavioral effects of perinatal exposure to diets with different omega-6:omega-3 ratios in mice.

OBJECTIVE: To investigate in mice the effect of diets enriched with soy or sunflower oil with different omega-6:omega-3 ratios on gestation, reproductive success, physical maturation, and the neurobiological development of the pups. METHODS: Dams were assigned, throughout gestation and lactation, to different groups: a commercial diet (CD), a soy oil-enriched diet (SOD), or a sunflower oil-enriched diet (SFOD). Measurements during gestation were dams' body weights and daily food intakes. Measurements in the offspring were physical parameters (body weight, body length, body mass index, fur appearance, pinna detachment, incisor eruption, eye opening, and puberty onset) and behavioral preweaning tests (surface righting reflex, negative geotaxis, and cliff avoidance). RESULTS: The SOD and SFOD dams became significantly heavier than the CD dams from gestational days 14 and 19, respectively, to parturition. There were no significant differences in gestational length or food consumption during pregnancy or lactation or in maternal weight during lactation. Diets did not modify litter size, sex ratio, survival index at weaning, or body weight. The SFOD and SOD offspring were significantly shorter than the CD offspring at weaning. The mean offspring physical scores of SOD and SFOD offspring were higher than CD offspring and simple reflexes were earlier in the SOD and SFOD groups. In SFOD offspring, puberty onset was significantly delayed, at postnatal days 26 and 27 in male and female offspring, respectively. CONCLUSION: This study suggests that the maintenance of an adequate omega-6:omega-3 ratio is necessary for the optimal growth and development of murine offspring. In populations that do not have sufficient provision of polyunsaturated fatty acids in the diet, their consumption would be advisable during gestation and lactation because these improve most neurodevelopmental outcomes included in this study.

Chronic administration of nonsteroidal-antiinflammatory drugs (NSAIDS): effects upon mouse reproductive functions.

Although nonsteroidal-antiinflamatory drugs (NSAIDs) are widely employed, reproductive side effects of prostaglandins long-term inhibition remain unknown. The objective of the present study was to evaluate the effects of chronic low/moderate NSAIDs doses upon mice reproductive functions. Male or female mice were injected (i.p. for 60 or 35 days respectively) with: ibuprofen doses A, B or C (0.56, 1.12 or 1.68 mg/100 g/day respectively) or piroxicam doses A, B or C (0.028, 0.056 or 0.084 mg/100 g/day respectively). Parameters evaluated were: a) in females, spontaneous and induced ovulation, oocyte maturity and spermatozoa migration through genital tract, b) in males, epididymal spermatozoa concentration, motility, viability, resistance to hypoosmotic shock, acrosomal status and membrane maturity and c) in both genders, in vitro and in vivo fertilization, reproductive hormones plasma levels and cyclooxigenase inhibition in reproductive tissues. In females ibuprofen (dose A) elicited a significant reduction in spontaneous and induced ovulation rates and piroxicam (dose A) diminished the concentration of spermatozoa found in the uterus after mating. Males treated with ibuprofen (dose B) showed a reduction in the in vitro fertilization ability. Our data reveal that chronic administration of ibuprofen or piroxicam can exert detrimental effects upon reproductive physiology, which depends on the doses and/or the drug employed.

Neutral alpha-glucosidase activity in mouse: a marker of epididymal function?

Neutral alpha-glucosidase (NAG) activity is considered a functional epididymal marker in several species. Unlike the rat, no NAG activity has been detected in mice. The aims of the present study were to evaluate NAG secretory activity (the supernatant of the incubated tissue) in mouse epididymis and to determine whether it could be used as a functional epididymal marker. Epididymides (whole or in parts) were incubated in the presence or absence of testosterone (10(-5) m) and secretory NAG activity was compared with known positive controls. Furthermore, we compared enzyme activity in epididymides from well-fed and undernourished mice (50% food restriction for 21 days), a model that alters the epididymal maturation processes. Spectrophotometric analysis revealed NAG activity in mouse epididymis (22.6 +/- 3.7 mU g(-1) tissue; n = 4), being higher in the caput. NAG activity was statistically higher in the caput than in the corpus and in the cauda. No significant differences existed between the caput NAG activity and complete epididymis NAG activity. In undernourished mice, we confirmed changes in epididymal maturation observed previously (i.e. increased number of immature spermatozoa and diminution of the sperm concentration). Concordantly, the epididymides of undernourished mice exhibited decreased enzyme secretory activity, which increased to values similar to those seen in controls following incubation in the presence of testosterone (22.5 +/- 2.6, 12.5 +/- 1.0 and 22.4 +/- 3.7 mU g(-1) tissue, n = 9 in control (n = 7), undernourished (n = 9) and undernourished + testosterone groups (n = 9), respectively). In conclusion, NAG activity was detected in mouse epididymis. Although the present study supports the possibility of using NAG as an epididymal marker, more studies are necessary to effectively prove that NAG activity can be used as an epididymal marker.

Time-related changes in functional activity and capacitation of chinchilla (Chinchilla lanigera) spermatozoa during in vitro incubation.

The application of assisted breeding programs for chinchilla, an endangered species, requires detailed knowledge about their gamete physiology. Main purposes of the present study were to examine the time-related changes during 8h in vitro incubation in parameters that reflect chinchilla sperm functional activity (including sperm motility, viability, membrane and acrosome integrity), and to determine the incubation time required for achieving in vitro sperm capacitation, evaluated through the quantification of the percentages of sperm that underwent the acrosome reaction in response to progesterone (P, 20 microM) or another acrosome reaction inducer the calcium ionophore, A23187 (20 nM). Semen was obtained by electroejaculation, subjected to swim-up and incubated for 0, 2, 4 and 8h. After these periods, sperm functional activity was assessed. In all treatments percentages of motile, viable and viable sperm with intact acrosomes decreased (p<0.001) after 8h of incubation. The percentages of swollen gametes decreased (p<0.001) after 2h of incubation. Capacitation of chinchilla sperm could be achieved within 4h, as indirectly demonstrated by the increase of acrosome reacted cells in response to P or A23187 (time x treatment interaction: p=0.02).

Improving the predictive value of the hypoosmotic swelling test in humans.

Using a combined hypoosmotic swelling-eosin (HOS-E) technique in human semen samples, we evaluated the frequency of dead swollen spermatozoa (dHOS) after 10 and 30 minutes of incubation, the correlation between total HOS-reactive (tHOS) and viable HOS-reactive (vHOS) spermatozoa with other seminal parameters, and the possibility that dead spermatozoa react to HOS. We obtained the following results: [1] some dead spermatozoa swell under hypoosmotic conditions and [2] HOS-E results correlate strongly with other seminal parameters. We recommend that HOS be performed after 10 minutes of incubation because [1] the increase in the incubation time enhances the percentage of dHOS, [2] there are no differences in vHOS percentages between 10 and 30 minutes, and [3] correlation coefficients between vHOS and tHOS with other parameters are very similar at 10 or 30 minutes of incubation.

A non-invasive method for assessing adrenal activity in the chinchilla (Chinchilla lanigera).

The Chinchilla is a rodent that was once abundant in the central Andes of South America. Excessive hunting for fur greatly reduced its distribution at the beginning of the twentieth century, and today Chinchilla species are nearly extinct in the wild. Although protected, wild populations of chinchilla are still declining. In general, this species has received little research attention and its biology is poorly understood. Improvements in captive breeding, husbandry, and genetic management are needed to ensure the conservation of the species. In this study, a noninvasive corticosteroid hormone monitoring technique was validated for use in Chinchilla lanigera. Two male domestic chinchillas were administered 3H-corticosterone (i.m.) to determine the time course and relative proportion of urinary and fecal steroid metabolites. Most radioactivity was detected in urine and feces 5-10 and approximately 30 h post-isotope administration, respectively. Corticosteroid immunoreactivity was assessed by corticosterone radioimmunoassay (RIA) and cortisol enzyme immunoassay (EIA). High-pressure liquid chromatography (HPLC) separation of corticosteroid metabolites in unprocessed urine revealed the presence of highly polar corticosteroid metabolites, but after enzymatic hydrolysis and diethyl ether extraction, most immunoreactivity co-eluted with unconjugated cortisol. A 'cause-and-effect' relationship between the administration of exogenous adrenocorticotrophic hormone (ACTH), and the appearance of increased urinary corticosteroid metabolites demonstrated the physiological relevance of these measures for evaluating adrenal status in male chinchillas. From a conservation perspective, these methods can aid in situ and ex situ initiatives designed to evaluate how environmental conditions and management strategies affect overall animal health, well-being and reproduction.

Estudio comparativo de la prueba de resistencia osmótica en semen de pacientes normospérmicos o dispérmicos / Comparative study of the test of osmotic resistence in semen of normospermic or dispermic patients

La alta incidencia de factor masculino en los casos de esterilidad conyugal justifican los intentos de un estudio más completo del semen. La prueba de resistencia osmótica (PRO), ha sido propuesta como un detector precoz de fallas en la integridad funcional de la membrana espermática. En el presente trabajo estudiamos las posibles correlaciones entre PRO y los parámetros convencionales del espermograma (de acuerdo a las técnicas recomendadas por la OMS) y comparamos los resultados de la PRO en especímenes normospérmicos y oligo, terato y/o astenospérmicos. En 75 casos se cuantificó: concentración espermática (en hemocitómetro), motilidad, velocidad de traslación (rápidos, lentos y no progresivos), morfología (coloración de Papanicolaou) y PRO (incubación del semen en solución de citrato de Na y fructosa, 150 mOsm/l, 37§C, 60 min). En todos los casos, la PRO se correlacionó significativamente con el porcentaje de formas móviles, rápidas o de morfología normal (r = 0.39; r = 0.39 y r = 0.35 respectivamente). A su vez, disminuye significativamente al incrementarse el número de alteraciones en las determinaciones del espermograma de rutina. En las muestras asteno, terato y oligospérmicas, los resultados de la PRO son significativamente inferiores a las con motilidad, morfología o concentración normal, respectivamente (p < 0.005 en todos los casos). Consideramos que la PRO representa una técnica accesible y de relativa sencillez que constituye un aporte relevante en el diagnóstico de la esterilidad masculina

Perfil de la morfologia espermatica en pacientes normospermicos y dispermicos / Profile of spermatic morphology in normospermic and dyspermic patients

The evaluation of spermatic morphology is of importance due to its prognostic value in potential male fertility, both in natural and in assisted reproduction. In the present work, the morphologic profile of samples of semen from normal and dispermic patients was determined, in order to establish a correlation between structure and function. Samples were obtained from male partners of infertile couples who attended andrologic consultation. The smears were stained by the Papanicolaou technique, and the criteria of the OMS and the recent modification of Kruger were followed to evaluate spermatic morphology. Of all the patients studied (n = 46), 35 were normospermics (A), 39 asthenospermics, 7 oligospermics, 2 terastospermics and 17 presented combined alterations. The average percentage of normal spermatozoa was of 23.7 +/- 1.23 in the whole population. When group A patients were compared with asthenospermics, significant differences were found in the percentage of spermatozoa with middle piece and tail alterations, in the last group (p < 0.02). Similarly, when samples were analysed according to the presence of alterations: none (A), one (B) two or more (C), it was observed that the percentage of normal forms decreased in the groups in that order (A < B < C); (A or B vs C p < 0.05). The percentage of tapering spermatozoa was significantly higher in group C (p < 0.01 vs A or B). From the above results, it appears that 1) the larger number of functional alterations is related to a higher percentage of structural anomalies, and 2) the deficient motility in the asthenospermic group, is associated to the middle piece and tail alterations.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional modifications evoked by physical training in rats

Se investigaron los efectos del entrenamiento físico (natación, 5 veces/semana durante lapsos de 2 a 60 min, durante 4 meses) sobre la actividad funcional de segmentos vasculares aislados, peso corporal y presión arterial sistólica en ratas macho. Después de 75 días, el peso corporal del grupo entrenado (E) fue significativamente menor que el del grupo control (C). La presión arterial sistólica decayó significativamente en E (p < 0.001 vs. C) a los 60 días. La tensión contráctil isométrica de la vena porta aislada al final del período de entrenamiento e incubada en medio de Krebs-Ringer-bicarbonato fue similar en ambos grupos (E: 15.36ñ0.82 mN, n=15; C:16.15ñ1.9 mN, n=10). Los componentes fásico y tónico de las contracturas inducidas por norepinefrina fueron mayores en E y la EC50 menor en C. No hubo, en cambio, diferenciais significativas en las respuestas contráctiles a ClK. La reactividad farmacológica de la arteria caudal ventral a los mismos agentes fue significativamente mayor en E. Nuestros hallazgos indican que el entrenamiento físico en ratas induce cambios funcionales adaptativos que incluyen modificaciones del peso corporal y la presión arterial sistólica. Los resultados obtenidos en músculo liso vascular aislado pueden ser explicados por incremento en la población de receptores adrenérgicos con disminución simultánea de su afinidad, como lo sugieren los valores de la EC50. Otros fenómenos adaptativos celulares (modificaciones en la fosforilación de proteínas, metabolismo...

Influence of the metabolic environment on oxygen uptake and isometric developed tension of isolated rat portal vein

Se cuantificaron simultáneamente la captación de oxígeno y la tensión contráctil isométrica (TCI) de la vena porta aislada de rata, incubada en medio sin glucosa, luego de la readmisión de sustratos metabólicos y de la adición de 2-deoxi-D-glucosa (2-DG) o insulina. En condiciones controles, la capatación de 02 fue de 0.128 + ou - 0.004 micronl de oxígeno/mg peso seco/m (n = 50). Después de 40 m de incubación en medio sin glucosa, la TCI y la captación de oxígeno fueron deprimidas en grado similar. La adición de glucosa 11 mM o piruvato, acetado, lactado o buricato 5 mM a venas hipodinámicas, provocó diferentes niveles de recuperación de los parámetros mecánico y metabólico, siendo piruvato y acetato los más efectivos. Insulina (0.1 U/ml) añadida 5 m previos a la readmisión de glucosa, incrementó la recuperación de la TCI sin modificar la captación de oxígeno. 2-DG 5.5 mM, cuando se añadió en medio sin glucosa abolió la TCI pero sólo deprimió la respiración celular en un 38% a los 20m; estos efectos fueron atenuados en presencia de glucosa. Los resultados sugieren que la captación de oxígeno en este vaso depende, entre otros factores, del sustrato exógeno. También evidencian relaciones entre la amplitud de la TCI y la actividad metabólica, así como la relevancia de las vías glucolíticas y oxidativas