Further studies on testicular lipids and glycogen in human patients with unilateral varicocele

Proton MR Spectroscopy in Assessing the Biochemical Milieu of Human Testes

Proton magnetic resonance spectroscopy (MRS), considered a connection between metabolism and anatomic and functional information provided by standard MRI, gives information on various tissue metabolites and their pathologic changes. Recently, proton MRS has been added as an adjunct tool to the multiparametric protocol of scrotal MRI, providing a new insight into the extremely complex biochemical milieu of normal and abnormal testes. This article reviews proton MR spectra of normal testes, showing age and bilateralism dependence. Disturbances of various metabolic pathways in testes of infertile men resulting in alterations of metabolite peaks are discussed. Preliminary data on proton MR spectra of testicular mass lesions are presented. LEVEL OF EVIDENCE: 5. TECHNICAL EFFICACY STAGE: 5.

Lipophagy Contributes to Testosterone Biosynthesis in Male Rat Leydig Cells

In recent years, autophagy was found to regulate lipid metabolism through a process termed lipophagy. Lipophagy modulates the degradation of cholesteryl esters to free cholesterol (FC), which is the substrate of testosterone biosynthesis. However, the role of lipophagy in testosterone production is unknown. To investigate this, primary rat Leydig cells and varicocele rat models were administered to inhibit or promote autophagy, and testosterone, lipid droplets (LDs), total cholesterol (TC), and FC were evaluated. The results demonstrated that inhibiting autophagy in primary rat Leydig cells reduced testosterone production. Further studies demonstrated that inhibiting autophagy increased the number and size of LDs and the level of TC, but decreased the level of FC. Furthermore, hypoxia promoted autophagy in Leydig cells. We found that short-term hypoxia stimulated testosterone secretion; however, the inhibition of autophagy abolished stimulated testosterone release. Hypoxia decreased the number and size of LDs in Leydig cells, but the changes could be largely rescued by blocking autophagy. In experimental varicocele rat models, the administration of autophagy inhibitors substantially reduced serum testosterone. These data demonstrate that autophagy contributes to testosterone biosynthesis at least partially through degrading intracellular LDs/TC. Our observations might reveal an autophagic regulatory mode regarding testosterone biosynthesis.

Differences in biochemical markers and body mass index between patients with and without varicocele

BACKGROUND

Varicocele is characterized by abnormal tortuosity and dilatation of the veins of the pampiniform plexus within the spermatic cord and is one of the causes of male infertility. This study aimed to evaluate the differences in biochemical markers and body mass index (BMI) between patients with and without varicocele.

METHODS

Between January 2004 and June 2009, 102 patients with varicocele (Group A) were evaluated. Ninety-five age-matched male patients who did not have varicocele were selected as controls (Group B). Varicocele was diagnosed by physical examination and confirmed by Doppler ultrasonography. The range of ages was between 18 and 50 years old. BMI, testosterone, serum alkaline phosphatase, calcium, lactic dehydrogenase, inorganic phosphate, gammaglutamine transpeptidase, uric acid, albumin, iron, cholesterol, triglyceride, alanine aminotransferase, and aspartate aminotrans-ferase levels were measured for all the subjects.

RESULTS

The mean age was 35.4 years in group A and 36.5 years in group B. Of the 102 patients in group A, 20 were grade 1 varicocele, 55 were grade 2 and 27 were grade 3. The BMI (mean +/- SD) of patients with varicocele (22.8 +/- 3.2) was significantly lower than that of patients without varicocele (24.9 +/- 4.1). Patients with varicocele had significantly lower serum levels of cholesterol than patients without varicocele (176.5 +/- 31.1 vs. 187.7 +/- 42.1 mg/dL). There were no significant differences for the other biochemical markers between the groups. Patients with grade 3 varicocele had a lower BMI than patients with grades 1 and 2 varicocele, but this was not significant. No significant differences were found for the other biochemical markers among the patients with grade 1, 2 or 3 varicocele.

CONCLUSION

Patients with varicocele had significantly lower serum levels of cholesterol than those without varicocele. In addition, the prevalence of varicocele was higher in patients with a lower BMI. Our findings suggest that patients with a greater BMI may have advantages in relieving the nutcracker phenomenon, which causes significant varicoceles.

Biochemical changes in testicular varicocele

The precise mechanism of the hypospermatogenesis associated with varicocele has remained uncertain, although there have been a number of speculations on the etiology of the associated infertility. The altered spermatogenesis has been attributed to the reflux of toxic metabolites from either adrenal or renal origin, disturbed hormone status, spermatic venous hypertension, testicular hypoxia secondary to stasis, and abnormal temperature regulation. However, the biochemical changes of the testicular tissue with varicocele have been only partially explored. This overview includes the available information on the biochemical change in the testes associated with varicocele as well as the introduction of basic biochemical aspects on the testes, which may give new insights into the possible pathophysiological mechanism of male infertility.