Effect of an LH-RH analog on cat testis and adrenal cortex function

The LH-RH analog-LH-RH-A (des-Gly10, [D-Trp6]-LH-RH ethylamide) was administerd in pharmacological doses (20 µg/Kg, sc) to adult male cats for 15 days and its effect on testis and adrenal function was determined. Dayly adminitration of the analog promoted a 3-fold increase in plasma testosterone levels after 7 days, indicating stimulatory effect of LH-RH-A (mean ñ SD for 6 treated cats, 1.88 ñ 0.35 vs 0.51 ñ 0.08ng/ml for 6 control cats). After 15 days the LH-RH-A-treated group exhibited a similar plasma testosterone concentration as the control group (mean ñ SD, 0.96 ñ 0.35 ng/ml vs 0.88 ñ 0.39 ng/ml, respectively), similar testicular and adrenal weights and no significant differences in the spermatogenic process. However, semiquantitative analysis of the zona fasciculata of the adrenals from the LH-RH-A treated group showed a significant accumulation of a substance not stained by hematoxylin-eosin or Schiff periodic acid (mean ñ SD of index of accumulation was 3.50 ñ 0.4 for treated cats vs 2.20 ñ 0.3 for control cats). The present results show that pharmacological doses of LH-RH-A have an effect on the adrenal cortex of cats without modifying spermatogenesis or plasma testosterone levels

Spermatogenic and steroidogenic testicular function in hypothyroid pubertal rats

The reproductive system of immature rats is held to be more influenced thyroid dysfunction than that of adult animals. The effect of hypothyroidism on the spermatogenic process of the rat has not been reported previously. th objetive of the present study was to investigate the spermatogenic and been reported previously. The objetive of the present study was to investigate the spermatogenic and steroidogenic functions of pubertal hypothyroid rats. Hypothyroidism by ad libitum ingestion of a 0.05% solution of propylthiouracil for 60 days, and confirmed by reduced plasma thyroxine levels in treated rats. Plasma testosterone level, the histological features of the testis and epididymis and the concentration of spermatozoa stored in the cauda epididymis were unchanged by hypothyroidism

Pituitary-testicular axis in benznidazole-treated rata

Benznidazole is used extensively throughout Latin America as an antiparasitic chemotherapeutic agent against chagasica infection. We have shown that rats chronically treated with 80 mg benznidazole Kg-1 day-1 for 30, days present severe testicular atrophy and arrest of spermatognesis. In the present experiments, plasma levels of testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (Prl- were inbestigated in rats receiving 10, 40 and 80 mg benznidazole Kg-1 day-1 for 30 days. No significant change in T, LH or Prl levels was observed in treated rats (P > 0.05). Plasma FSH concentration, however, was markedly invreased (P < 0.05 by benzidazole treatment (40 and 80 mgKg-1 day-1) and remained high for 90 days after drug treatment was discontinued

Histochemical and histological analysis of the leydig cells of cats treated with a supraphysiological dose of LH-RH analog

An LH-RH analog (des-Gly10, [D-Trp6]-LH-RH A) was administered to adult male cats for 67 days (20 microng/Kg,sc) in order to study its inhibitory effects on the structure of Leydig cells, as deter,mined by histological and histochemical-morphometric techniques. Histological examination showed that LH-RH A promotes a decrease in the volume of the interstitial tissue. In addition, Leydig cell nuclei exhibited marked structural alterations. Morphometric analyses utilizing histochemistry of the enzyme 3-ß-hydroxysteroid dehydrogenase (3-ß-HOST-D) as a marker of Leydig cells also demostrated a signifcant decrease of the relative volume occupied by the Leydig cells isn the testis

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