Introduction: Thyroid hormones play a major role in the regulation of testicular maturation and growth and in the control of Sertoli and Leydig cell functions in adulthood. When naturally occurring, hypothyroidism causes male hypogonadotropic hypogonadism and Sertoli cell function disorders, but when iatrogenic and methimazole-induced its influence on the pituitary-testicular axis function with respect to Sertoli cells is poorly known.
Material and Methods: Male adult Wistar rats (n = 14) were divided into two groups: E – taking methimazole orally for 60 days, and C – control animals. After 60 d, the concentrations in serum of testosterone, follicle-stimulating and luteinising hormones, and inhibins A and B were measured. Testicles were examined morphologically: the apoptotic Sertoli cell percentage (ASC%) and number of these cells functional per tubular mm2 (FSCN/Tmm2) were calculated.
Results: In group E, inhibin A was higher while inhibin B was lower than in group C. ASC% was higher and FSCN/Tmm2 lower in group E than in group C.
Conclusion: A specific modulation of Sertoli cell function in the course of methimazole-induced hypothyroidism leads to a simultaneous concentration increase in inhibin A and decrease in B. Inhibin A might share responsibility for pituitary-testicular axis dysfunction and hypogonadotropic hypogonadism in this model of hypothyroidism.
Methimazole-induced hypothyroidism is a clinical problem in the treatment of hyperthyroidism in people and animals and is an example of metabolic disease that can lead to fertility disorders and can give elastographic testicular changes.
Material and Methods
Ultrasound elastography using the Esaote MyLab Twice ultrasound system and a morphological examination of testes were performed in seven methimazole-administered (group E) and seven healthy rats (group C).
The elasticity ratio of strains in the scrotal wall of the near-field test area to testicular tissue (ELX-T-RAT) and hardness percentage of strained tissues in the defined area of a testicle (ELX-T%HRD) in group E were statistically significantly lower than in group C. The degree of spermatogenesis was statistically significantly higher in group E than in group C and similarly seminiferous tubule diameters in group E were statistically significantly higher than in group C. Body weight and testicular weight in group E were statistically significantly lower than in group C.
Changes in the elastographical parameters of testes may result from disorders secondary to hypothyroidism. The usefulness of elastography is noteworthy in the case of evaluation of testis function in patients with some metabolic disorders.