The effectiveness of insulin therapy in the functional and morphological recovery of leydig cells in rats submitted to Diabetes mellitus

The effects of systemic insulin administration at different concentrations on the testicular tissue of diabetic adult rats, induced by streptozotocin, are evaluated by the morphological analysis of spermatogenic process. Twenty-four adult male rats were divided into 1) Control Group: they received citrate buffer, by intraperitoneal injection; 2) Diabetic Group: induced by intraperitoneal injection of streptozotocin (60 mg. kg-1 of body weight); 3) Insulin 50%: induced diabetes treated with half of standard dosage of insulin; 4) Insulin 100%: induced diabetes treated with standard dose of insulin. After eight weeks, animals were weighted and anesthetized; testicles were removed and processed in resin. Body and testicular weight of diabetic rats decreased when compared to that of control. Parameters increased with insulin therapy. Testosterone levels were low in diabetic animals but rates recovered after insulin therapy. Nuclear diameter and volume of Leydig cells decreased in diabetic rats although they significantly increased after insulin therapy. Results showed that the administration of insulin in diabetic rats promoted a protective effect of testicular parenchyma, enhancing efficient recovery on testosterone levels and increase in daily sperm production.

Protein restriction during intrauterine and lactation periods: effects on testicular development in pre-puberty rats / Restrição proteica durante os períodos intrauterino e lactacional: efeitos no desenvolvimento testicular de ratos pré-púberes

Current study investigates the effects of maternal protein restriction during pregnancy and lactation on the testis of immature rats. Female Wistar rats were mated and, after confirming pregnancy, they were divided into two groups: undernourished group (UG) fed on a diet with casein 8%, and control group (CG) fed on a diet with casein 17 %, during pregnancy and lactation. After weaning, male offspring from the two experimental groups were fed on normal diet up to 35 days old when they were euthanized. Body and testicular weights decreased in UG when compared to those in CG. Volumetric density of seminiferous tubules was higher in CG whilst intertubular space increased in UG. The number of lumenated seminiferous tubules was higher in CG than in UG. Tubular diameter, seminiferous epithelium height and total length of seminiferous tubules were lower in UG. Round spermatids were frequently found in seminiferous tubules cross-section of CG. On the other hand, spermatocytes I in prophases was the germ cell commonly found in seminiferous tubules cross-sections of UG. Undernutrition during pregnancy and lactation period of the male Wistar rats altered the morphometric testicular parameters related to tubular compartment and delayed the onset of spermatogenesis.

O objetivo deste estudo foi investigar o efeito da restrição proteica materna durante prenhez e lactação no testículo de ratos imaturos. Fêmeas de ratos Wistar foram acasaladas e, uma vez confirmada a gestação, foram divididas em dois grupos e alimentadas durante a prenhez e a lactação: grupo desnutrido (GD), dieta com caseína 8%, e grupo controle (GC), dieta com caseína 17%. Após o desmame, os machos de ambas as proles receberam a dieta normal até os 35 dias de idade, quando ocorreu a eutanásia. O peso corporal e o peso testicular diminuíram no GD com relação ao GC. A densidade volumétrica dos túbulos seminíferos foi maior no GC, assim como o espaço intertubular aumentou no GD. O número de túbulos seminíferos luminados foi maior no GC comparado ao GD. Diâmetro tubular, altura do epitélio seminífero e comprimento total dos túbulos seminíferos diminuíram no GD. Espermátides arredondadas foram frequentemente encontradas nas seções transversais do GC. Por outro lado, espermatócitos I em prófase foram o tipo celular mais frequentemente encontrado no GD. A desnutrição durante a gestação e a lactação em ratos Wistar machos alteraram parâmetros morfométricos testiculares relacionados ao compartimento tubular e atrasou o início da espermatogênese.

Evaluation of quantitative parameters of Leydig cell in diabetic adults rats / Avaliação de parâmetros quantitativos de células de Leydig em ratos diabéticos adultos

The goal of present study was to evaluate the effects of diabetes on quantitative parameters of Leydig cells. Twelve adults Wistar rats were divided in: 1) Diabetic Group (DG), which was induced by a single intraperitoneal injection of streptozotocin (60 mg kg-1 of body weight); and 2) Control Group (CG), which received citrate buffer intraperitoneal. After eight weeks of diabetic induction, the animals were weighted, anesthetized and testicles were removed and routinely processed to paraffin embedded. Body weight (40%) and testicular weight (18%) of diabetic rats were significantly lower than control group. Diabetic rats showed an increase in interstitial compartment but the tubular compartment did not differ. The individual volume of Leydig cells and nuclear diameter were lower in DG. However, the population of these cells was increased. In conclusion, diabetes induced by streptozotocin in adult rats promoted alterations in testicular compartments and changes on volume, nuclear diameter and population of Leydig cells, compromising the testicular function.

O objetivo do presente estudo foi avaliar os efeitos do 'diabetes' nos parâmetros quantitativos de células de Leydig. Doze ratos machos adultos foram divididos em: 1) Grupo Diabético (GD) induzidos por injeção intraperitoneal única de estreptozotocina (60 mg kg-1 de peso corporal); e 2) Grupo Controle (GC) receberam tampão citrato, via intraperitoneal. Após oito semanas da indução, os animais foram pesados, anestesiados, os testículos foram removidos e processados rotineiramente em parafina. O peso corporal (40%) e testicular (18%) dos ratos diabéticos reduziu significativamente em relação ao grupo controle. Ratos diabéticos mostraram aumento no compartimento intersticial, mas o compartimento tubular não apresentou diferença significativa. O volume individual e o diâmetro nuclear de células de Leydig reduziram em GD. No entanto, a população dessas células aumentou. Em conclusão, o 'diabetes' induzido por estreptozotocina, em ratos adultos, promoveu alterações nos compartimentos testiculares e mudanças no volume, diâmetro nuclear e população das células de Leydig, comprometendo a função testicular.