RESUMO
Idiopathic varicocele is closely associated with male infertility or subfertility. Sertoli cell is a very important regulator of spermatogenesis. We investigated the morphofunctional alterations in the Sertoli cell and its possible involvement in the establishment of testicular primary lesion in experimental left-sided varicocele, induced from peripuberty. Twenty-five male peripubertal rats (44 days postpartum [dpp]) were distributed into two groups: control (C) and varicocele (V). Experimental left varicocele was induced in rats through the partial ligature of the left renal vein. Euthanasia was performed at 100 dpp. Testicular histopathology and testosterone plasmatic level were evaluated. Transferrin and vimentin proteins were, respectively, used as immunomarkers of Sertoli cell function and structure. Significant reductions in vimentin and transferrin expressions were noticed in androgen-dependent stages (VII and VIII) of the seminiferous epithelium cycle in V rats; testosterone plasmatic level was also reduced. Bilateral testicular histopathological alterations were found in V rats, mainly massive germ cell desquamation. The histological damage and changes in protein expressions occurred bilaterally. The relevant impairment of the functional and structural characteristics of the Sertoli cell, together with the typical massive germ cell desquamation, indicates that Sertoli cell changes can primarily contribute to the significant testicular dysfunction associated with varicocele.
Assuntos
Infertilidade Masculina/etiologia , Células de Sertoli/metabolismo , Espermatogênese/efeitos dos fármacos , Varicocele/etiologia , Animais , Modelos Animais de Doenças , Regulação da Expressão Gênica , Células Germinativas/metabolismo , Heparina/farmacologia , Ligadura , Masculino , Prognóstico , Ratos , Ratos Wistar , Veias Renais/metabolismo , Testículo/metabolismo , Testosterona/farmacologia , Transferrina/genética , Transferrina/metabolismo , Vimentina/genética , Vimentina/metabolismoRESUMO
Venous and arterial walls are responsive to sympathetic system and circulating substances, nevertheless, very few is known about the venous blood flow regulation simultaneously to arterial vascular beds. In this study, we compared the venous and arterial blood flow regulation in visceral and muscular beds upon injection of different doses of vasoactive drugs which act in arterial vascular beds. Anesthetized adult male Wistar rats underwent to right femoral artery and vein cannulation for hemodynamic recordings and infusion of drugs. Doppler flow probes were placed around the left renal artery and vein, and left femoral artery and vein to evaluate the changes in flood flow. Phenylephrine (PHE) injection (α1-adrenergic receptor agonist) elicited vasoconstriction in all arteries and veins. Intravenous prazosin (PZS) (1mg/kg, α1-adrenergic receptor blocker) caused renal artery vasodilation, but not in the other beds. Vasoconstrictor effect of PHE was abolished by PZS in all vascular beds, except in femoral vein. Phentolamine (PTL) injection (1mg/kg, α1/α2-adrenergic receptor blocker) produced renal artery vasodilation with no change in other beds. After PTL, the vasoconstriction evoked by PHE was abolished in all vascular beds. Sodium Nitroprusside (SNP), a nitric oxide donor, elicited vasodilation in all beds, and after PTL but not post PZS injection, SNP enhanced the vasodilatory effect in femoral vein. Our findings suggest that the vasoconstriction in renal and femoral veins is mediated by different subtypes of α-adrenoceptors. The nitric oxide-dependent vasodilation in femoral vein enhances when α2-adrenoceptors are not under stimulation, but not in the other vascular beds investigated.