Avaliaçöes ultra-sonográfica, macroscópica e histológica da biopsia testicular em ovinos / Assessment of ultrasonographic images and gross and microscopic lesions of the testicular biopsy in sheep

Devido ao fato da biopsia testicular poder acarretar hemorragia, inflamaçäo, degeneraçäo, aderência e fibrose, especialmente com as técnicas incisionais ou abertas, este trabalho avaliou a aplicabilidade de uma técnica menos invasiva (biopsia com agulha Tru-Cut) em ovinos na obtençäo de material para histologia e acompanhou as lesöes testiculares posteriores. Trinta carneiros foram igualmente divididos em três grupos: 1) controle, animais näo submetidos à biopsia; 2) submetidos à biopsia + cola de fibrina nos locais da biopsia testicular e incisöes da pele; e 3) submetidos à biopsia + sutura da pele escrotal após a biopsia. Exames ultra-sonográficos foram realizados pré e pós biopsia. No centésimodia, os testículos foram avaliados macro e microscopicamente após orquiectomia. A ultra-sonografia permitiu mapear as alteraçöes ocorridas e acompanhar a evoluçäo das seqüelas. Ao exame macroscópico, pequenas áreas de calcificaçäo foram observadas em 55 e 70 por cento dos testículos nos grupos 2 e 3, respectivamente. A biopsia com agulha Tru-Cut forneceu material suficiente para histologia mas ocasionou lesöes focais restritas à área biopsiada. Apesar da possível ocorrência de calcificaçäo e outras lesöes mínimas, foi demonstrado que a biopsia com agulha Tru-Cut em ovinos é um procedimento seguro por näo ter comprometido significativamente as características estruturais e funcionais dos testículos

Sexual behavior and fertility of male rats submitted to prolonged immobilization-induced stress

In order to investigate whether prolonged stress interferes with the onset of sexual behavior at puberty and with fertility at adulthood, prepubertal male Wistar rats (40 days of age) were immobilized 6 h a day for 15 days (up to early puberty) or for 60 days (until sexual maturity). Pubertal stressed rats showed a two-fold increase in the latency for the first mount (probably due to repeated aversive experience in which a change of environment was always followed by immobilization) and a 2.5-fold increase in the frequency of thrusting (indicative of enhanced sexual performance). The apparently stimulatory effect of prolonged stress on the onset of sexual behavior is discussed in terms of increased testosterone level and interference with the complex interchanges between the neurotransmitters/neuropeptides involved in the central control of male sexual activity. Adult stressed animals were mated with normal females, which became pregnant but exhibited a more than two-fold increase in both pre-implantation and post-implantation loss, probably due to a smaller rate of fertilization and/or fertilization with damaged spermatozoa

Efeitos do acetato de chumbro diluido e dinamizado (preparacao homeopatica) no tratamento do Saturnismo / Effects of diluted and dynamised lead acetate in the treatment of Saturnism

Os autores estudam o efeito do acetato de chumbo diluido e dinamizado (preparacao homeopatica) em ratos machos(Wistar) intoxicados por acetato de chumbo. Os resultados evidenciaram a eficacia da preparacao homeopatica comparavel a do EDTA na diminuicao da plumbemia.

Chemical sympathectomy blocks androgen biosynthesis during prepuberty

Twenty-one-day old male Wistar rats were injected subcutaneously with guanethidine (GUA) at doses of 5 and 10 mg kg-1 day-1 for 20 days. Animals were sacrificed by decapitation during the prepubertal (41 days of age) and early-pubertal (51 days of age) periods of sexual development. The tests were collected, frozen in liquid N2 and stored at -70oC until determination of testicular progesterone (P), androstenedione (A) and testosterone (T). Higher levels of P (2.18 +/- 0.24 ng/g, control = 1.24 +/- 0.16 ng/g) associated with decreased with decreased levels of androgens (A = 0.26 +/- 0.06 ng/g T = 2.05 +/- 0.19 ng/g; control = 1.86 +/- 0.76 ng/g and 8.48 +/- 1.16 ng/g, respectively) were observed in 10 mg GUA-treated rats of prebubertal age, while only P levels (3.12 +/- 0.51 ng/g, control = 1.73 +/- 0.27 ng/g) were incresead in rats of early pubertal...

Prepubertal development of rat prostate and seminal vesicle following chemical sympathectomy with guanethidine

1. The internal genital organs of prepubertal, 21-day old male Wistar rats were sympathectomized by ip injection of guanethidine (G), at doses of 5 mg/kg per day (N = 10) or 10 mg/kg per day (N = 10), for 20 days. Controls (N = 10) received saline. 2. Plasma testosterone level (measured by radioimmunoassay) decreased significantly in sympathectomized rats from 4.11 +/- 0.57 to 1.76 +/- 0.37 ng/ml (5 mg/kg G) and to 1.17 +/- 0.26 ng/ml (10 mg/kg G). Plasma levels of luteinizing and follicle-stimulating hormones and of prolactin were unaltered. 3. Chemical denervation caused a significant decrease in ventral prostate wet weight from 74.3 +/- 5.5 to 59.3 +/- 4.7 mg (5 mg/kg G) and to 54.6 +/- 4.1 mg (10 mg/kg G) and in seminal vesicle wet weight from 36.5 +/- 6.8 to 31.7 +/- 5.2 mg (5 mg/kg G) and to 21.3 +/- 1.6 mg (10 mg/kg G). 4. The potential secretory activity of the prostate (measured in terms of fructose content) decreased significantly in guanethidine-treated rats from 0.38 +/- 0.02 to 0.30 +/- 0.02 mg/g (5 mg/kg G) and to 0.20 +/- 0.02 mg/g (10 mg/kg G). The seminal vesicle fructose content (0.33 +/- 0.04 mg/g for controls), however, was not altered by chemical denervation. 5. Our data suggested that sympathetic neurons may be involved in the control of LH receptors, at least in the prepubertal phase of sexual development. They may also be directly related to growth and secretory activity of the male accessory sex glands

Saturnism in the male rat: endocrine effects

The effect of exposure to lead on endocrine function was studied in pubertal rats treated with 1.0 g/l lead acetate (PbAc) in drinkin water for 20 days (subacute group) or 9 months (chronic group) in addition to iv injections of PbAc (0.1mg/100g body weight) every 10(subacute group) or 15 days (chronic group). Although basal levels of testosterone were higher both in the plasma and in the testes of acuctely intoxicated animals, the ciruclating levels of lutinizing hormone (LH) were not affected in either group, nor was the LHRH content of the median eminence. The density of [125I]LH/hCG biding sites in testicular homogenates was reduced by saturnism in both groups. Howeverm the apparent affinity constant of the hormone-receptor complex significantly increased. These data can be viewed as the result of a mixture of specific lead toxicity (e.g., at the enzyme level) with other more general actions (e.g., at the level of the hypothalamus-pituitary-testicular axis)

Análise morfométrica do testículo e epididimo do rato na fase inicial da intoxicaçäo pelo chumbo

Ratos machos adultos foram intoxicados por ingestäo "ad libitum" de acetato de chumbo nas concentraçöes de 0,5 g/1 e 1,0 g/l, durante 90 dias. Ao final do período experimental, a intoxicaçäo foi confirmada pelo aumento acentuado na concentraçäo de chumbo no sangue, aliado `a diminuiçäo dos valores de hematócrito e hemoglobina e aumento da glicemia. Nesta fase inicial da intoxicaçäo, näo se observaram alteraçöes no diâmetro dos túbulos seminíferos, na altura do epitélio germinativo, no ritmo do processo espermatogênico e na produçäo de espermatozóides. A cabeça do epidídimo näo apresentou também qualquer alteraçäo estrutural. A cauda do epidídimo, por outro lado, exibiu aumento significativo no diâmetro do ducto e diminuiçäo na altura do epitélio. A concentraçäo de espermatozóides armazenados na regiäo caudal do epidídimo mostrou-se significativamente aumentada nos aniamis tratados com chumbo. Os resultados revelam o envolvimento precoce da cauda do epidídimo na intoxicaçäo pelo chumbo, e sugerem um distúrbio no mecanismo neuroendócrino que controla as múltiplas funçöes epididimárias