Simultaneous activity of male and female gonads in intersex hermit crabs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hematological values and body, heart and liver weights of male and female broiler embryos of young and old breeder eggs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Male and female interactions during courtship of the Neotropical damselfly Mnesarete pudica (Odonata: Calopterygidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Differential vascular adaptive response to stress exposure in male and female rats: Role of gonadal hormones and endothelial cells

Although there are reports concerning a vascular adaptive response to stress in males, this is not yet defined in females. The aim of this study was to delineate functional gender differences in the rat vascular adaptive response to stress and to determine the ability of sex hormones to modulate the stress-induced vascular adaptive response. Responses to noradrenaline were evaluated in aortas, with and without endothelium, from intact, gonadectomized and gonadectomized-hormone-replaced males and females submitted or not to stress (2-h immobilization). Reactivity of the aorta of stressed and non-stressed intact males and females (n = 6-14 per group) was also examined in the presence of L-NAME or indomethacin. Stress decreased and gonadectomy increased maximal responses to noradrenaline in aortas with intact endothelium from both genders. Stress also reduced noradrenaline potency in males. In females, but not males, stress decreased the gonadectomy-induced noradrenaline hyper-reactivity to near that of intact non-stressed rats. Hormone replacement restored the gonadectomy-induced impaired vascular adaptive response to stress. L-NAME, but not indomethacin, abolished the stress-induced decrease in aorta reactivity of males and females. None of the procedures altered reactivity of aortas denuded of endothelium. Conclusion: Stress-induced vascular adaptive responses show gender differences. The magnitude of the adaptive response is dependent on testicular hormones and involves endothelial nitric oxide-system hyperactivity.

Morphology and histology of male and female reproductive systems in the inseminating species Scoloplax distolothrix (Ostariophysi : Siluriformes : Scoloplacidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Male and female reproductive morphology in the inseminating genus Astroblepus (Ostariophysi: Siluriformes: Astroblepidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acid phosphatase activity in gerbil prostate: comparative study in male and female during postnatal development

The prostate is present in both male and female mammals. It is composed of secretory epithelium, connective stroma, smooth muscle and neuroendocrine cells, which are under hormonal regulation. Acid phosphatases catalyze the hydrolysis of orthophosphate monoesters. We have compared the expression of acid phosphatases in gerbil (Meriones unguiculatus) prostate glands in both sexes using young, adult and old animals. Eighteen prostates were isolated, frozen, sectioned, fixed, incubated with sodium beta-glycerophosphate sodium, washed with acetate buffer solution, treated with ammonium sulfide and counterstained with Methyl-Green aqueous solution. Ultracytochemical analyses were also conducted. This substrate revealed total acid phosphatase activity. The expression of the enzyme was heterogeneous, occurring in all ages during postnatal development. The data. revealed that the female prostate matured before the male prostate. In addition, acid phosphatase activity in both sexes was regulated by androgen variation concomitant with development. (C) 2004 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Exposure to ethinylestradiol during prenatal development and postnatal supplementation with testosterone causes morphophysiological alterations in the prostate of male and female adult gerbils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sex Determination and Female Reproductive Development in the GenuSchistosoma: A Review

Os parasitas do gênero Schistosoma situam-se entre os primeiros metazoários que desenvolveram sexos separados, determinado cromossomicamente no ovo fertilizado. Apesar da ocorrência de cromossomos sexuais específicos, as fêmeas de Schistosoma não atingem a maturidade somática e sexual sem a presença dos machos. Na verdade, um dos aspectos mais controversos e, ao mesmo tempo, mais fascinantes, envolvendo o desenvolvimento sexual das fêmeas está em se desvendar a natureza do estímulo que controla e mantém tal processo. Muito embora a natureza do estímulo (físico ou químico) seja motivo de controvérsia, concordam os mais diferentes autores que o acasalamento é um requisito indispensável para que ocorra a maturação e migração das fêmeas para o sítio definitivo de permanência no sistema vascular do hospedeiro vertebrado. Admite-se, ainda, que o estímulo não é espécie-específico e, em alguns casos, nem mesmo gênero-específico. Não obstante a existência de um número considerável de artigos dedicados ao tema, não há um consenso sobre o processo (ou processos) que controla(m) o encontro de machos e fêmeas no sistema circulatório do hospedeiro vertebrado, bem como está por ser determinada a natureza do estímulo, oriundo dos machos, que controla e mantém o desenvolvimento somático e sexual das fêmeas. Ao longo dos anos os machos de Schistosoma têm sido considerados, por vezes pejorativamente, os irmãos, os músculos ou o fígado das fêmeas. em síntese, resta saber se a natureza do estímulo responsável pelo desenvolvimento das fêmas envolve a transferência de hormônios, nutrientes, a mera estimulação tátil ou a combinação de dois ou mais desses fatores

Protandry and female size-fecundity variation in the tropical butterfly Brassolis sophorae

Protandry (the emergence of males before fe males) is currently explained either as a mating strategy to maximize number of matings in the males, or a way to minimize pre-reproductive mortality in females, Models of protandry have generally ignored variation in female quality (reproductive potential). We recorded the sex ratio, female body mass, wing length and potential fecundity (number and mass of eggs) of the tropical butterfly Brassolis sophorae through the emergence period. Temporal variation in female size and fecundity correlated with male potential for acquiring mates. Females from the end of the emergence period showed lower fecundity and size. Males emerging before and close to the median date of the female emergence period had greater mating opportunities. Males emerging either very early or late were penalized by few mating opportunities, or by encounters with small: low-quality females, respectively.

Bone healing in drill hole defects in spontaneously hypertensive male and female rats' femurs. A histological and histometric study

Objective: the aim of this study was to evaluate the bone healing in spontaneously hypertensive rats (SHR) and compare the results with normotensive rats, evaluating male and female animals.Methods: A bone drill defect was created in the left femur of 24 SHR (12 males and 12 females) and 24 normotensive rats (12 males and 12 females). The animals were divided into two groups and sacrificed 7 and 21 days after the surgical procedure. After the routine laboratory processing, histological and histometric analysis were carried out and data were submitted to ANOVA and Tukey's test (5%).Results: Males and females from the same group had similar histological characteristics. After seven days, all animals presented irregular bone trabeculae. The periosteal osteoblasts were flattened in SHR, and presented a cuboid shape in normotensive animals. After 21 days, the bone defects of all specimens showed a linear closure in all the superficial extension. In addition, SHR presented flattened osteoblasts surrounding the bone trabeculae, while normotensive ones showed cuboidal cells. Statistical analysis of the histometric data indicated similar means between the male and female groups, except for normotensive rats on day 7. In addition, a larger amount of new bone formation was observed in hypertensive when compared to normotensive rats on day 27, in males as well as females.Conclusion: We conclude that bone healing in SHR was more significant than in normotensive ones, as shown by the histological and histometric evaluation 21 days after surgery.

Immunolocalization of estrogen and progesterone receptors in neuroendocrine tumors of lung, skin, gastrointestinal and female genital tracts

Expression of estrogen (ER) and progesterone (PR) receptors has traditionally been associated with hormone-responsive organs, such as breast, ovary, and endometrium, and carcinomas arising therefrom. More recently, examples of ''unexpected'' ER or PR expression have been reported, particularly in tumors of endocrine tissues, such as thyroid and pancreatic islet cells. We tested the hypothesis that neuroendocrine tumors of various primary and metastatic sites might also express ER or PR or both by performing a retrospective immunohistochemical study in a series of 59 formalin- or mechacarn-fixed neuroendocrine carcinomas of various sites, including lung, skin, gastrointestinal and female genital tracts, and including carcinoid and atypical carcinoid tumors, small cell carcinomas, and Merkel cell carcinomas. We employed the anti-ER monoclonal antibody 1D5 and the anti-PR monoclonal antibody PgR1A6 using standard immunohistochemical techniques after microwave-based heat-induced epitope retrieval. Two of 28 carcinoid tumors demonstrated ER positivity; six of 30 cases were positive for progesterone receptor only. In addition, PR expression was found in one of two cases of atypical carcinoid, in five of 25 cases of small cell carcinoma, and in one of two cases of Merkel cell carcinoma. None of the atypical carcinoids, small cell carcinomas, or Merkel cell carcinomas were ER positive. In most cases, the fraction of tumor cell nuclei that were positive was <50%. These studies add the spectrum of neuroendocrine tumors that can express these hormone receptors. Similar to the pattern previously described in the subsets of meningiomas and islet cell tumors, PR but not ER is detectable in most cases. These results underscore the caution that should be exercised in determining tissue origin of metastatic carcinomas based only on detection of hormone receptors by immunohistochemistry.

Effects of histone hyperacetylation on the preimplantation development of male and female bovine embryos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of prenatal exposure to deltamethrin on forced swimming behavior, motor activity, and striatal dopamine levels in male and female rats

The effects of prenatal exposure of rat pups to 0.08 mg/kg deltamethrin (DTM) on physical, reflex and behavioral developmental parameters, on forced swimming and open-field behaviors, and on striatal monoamine levels at 60 days of age were observed. Maternal and offspring body weight, physical and reflex development were unaffected by the exposure to the pesticide. At 21 days of age, open-field locomotion frequency and immobility duration of male and female offspring were not different between control and exposed animals. However, male rearing frequency was increased in experimental animals. A decreased immobility latency to float and in general activity after the swimming test in male offspring was observed at adult age; no interference was detected in the float duration during the swimming test. In addition, these animals presented higher striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels without modification in dopamine (DA) levels and an increased DOPAC/DA ratio. These data indicate a higher activity of the dopaminergic system in these animals. Noradrenaline (NA) levels were increased, while MHPG levels were not detectable in the system studied. Serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as well as the homovanillic acid (HVA)/DA ratio, were not modified by the exposure to the pesticide. No changes were observed in swimming and open-field behaviors nor were there any changes in striatal monoamines or their metabolites in the female experimental group. In relation to the pesticide formula, the present data showing that prenatal exposure to DTM alters latency to float and the activity of striatal dopaminergic system might reflect a persistent effect of the pesticide on animal motor activity, mainly in males. on the other hand, the decrease in general activity observed in experimental male rats suggests higher levels of emotionality induced by previous exposure to the swimming behavior test in relation to control animals. Data gathered in the present study may be important for the assessment of the safety of pyrethroid insecticides. (C) 2001 Elsevier B.V. All rights reserved.

Chronic renal failure in male and female rats

Gender influences the progression of chronic renal failure (CRF). We studied male (M) and female (F) Wistar rats for 90 days: castrated (CMc, n=7; CFc, n=6) and non castrated controls (CM, n=9; CF, n=6); castrated (CRFMc, n=8; CRFFc, n=6) and non castrated animals submitted to 5/6 nephrectomy (CRFM, n=13; CRFF, n=6). Data are expressed as mean ± SEM. Proteinuria (PTN) was higher in CRFM (554 ± 69mg/24h) compared to CRFMc (277 ± 85 mg/24h), but not in females (CRFF=193 ± 20mg/24h, CRFFc=164 ± 71mg/24h). Mesangial fractional volume increased in all CRF animals. CRF animals showed an increase of glomerular sclerosis index (GSI) and tubulointerstitial damage (TID) but in a smaller proportion in male castrated animals; the opposite occurred with females: castration induced an increase of these parameters. CRF animals showed increased cortical and glomerular fibronectin (FN) rates. Castration decreased glomerular and cortical FN rates in CRFM but not in females. In conclusion, proteinuria was higher in CRFM and probably led to glomerular and interstitial damage, as well as to FN accumulation, castration seems to protect against development of PTN, TID and FN accumulation in males. Castrated female rats presented mesangial expansion, with no changes in PTN, TID and FN rates. It seems that female sex hormones do not protect against renal disease progression, instead, we suggest that male sex hormones lead to acceleration of CRF.