E. A. Jannini

Ontogeny and regulation of variant thyroid hormone receptor isoforms in developing rat testis

High affinity-low capacity nuclear triiodothyronine (T3) receptors (TRs), identified as a product of c-erbAα proto-oncogene, are expressed in prepubertal rat Sertoli cell. At this age, exogenous T3 treatment as well as hypothyroidism affects Sertoli cell functions. We examined the ontogenetic expression pattern of TRs in the rat testis. Northern analysis confirms that TRs are expressed at high level from fetal development until prepubertal period. Rnase protection analysis demonstrates that TRα2, the variant isoform of TRα1, is constitutively expressed at all ages, while TRα3 is absent in the adult gonad. While TRα1 and TRα2 expression declines during development, Rev-erbAα (Rev), the antisense mRNA encoded by the same c-erbAα genomic locus, increases beginning 5 days after birth and maximizing in adulthood. TRα1, TRα2, and Rev mRNAs do not appear to be directly regulated by thyroid hormone in testis; however, short-term neonatal hypothyroidism leads to the expression of TRα1 and its variant in adult testis, which is absent in control coeval animals. Thus, during development of rat testis, the levels of messages of genes encoded in the c-erbAα genomic locus have different ontogenetic control. The ontogenetic profile of TRα1 and its variant isoforms within the seminiferous epithelium suggests that these receptors are involved in the differentiation of the male gonad.

Might erectile dysfunction be due to the thermolabile variant of methylenetetrahydrofolate reductase

Hyperhomocysteinemia is considered one of the most important cardiovascular risk factors increasing considerably the risk of stroke and myocardial infarction. With respect to endothelial function, direct effects of hyperhomocysteinemia on vascular endothelial cells have been demonstrated through the reduction of endothelial nitric oxide production. In this paper, we report the case of a young man with homozygote genotype mutated with 5-methylenetetrahydrofolate reductase (MTHFR) thermolabile variant who, in the absence of relational stress, developed an erectile dysfunction (ED) refractory to the vasoactive type-V phosphodiesterase (PDE5) inhibitor therapy. After one month of treatment with 5 mg/day folic acid and 1000 μg/day cyanocobalamin, the patient restarted the assumption of 50 mg sildenafil, obtaining satisfying erections during sexual intercourse. We suggest that hyperhomocysteinemia may interfere with penile blood supply and, thus, be responsible for ED. If this relationship is confirmed, plasma levels and urinary homocysteine (HCy) should be evaluated in selected young patients with vascular ED. Furthermore, careful attention should be given to the risk of ED when dealing with this metabolic disturbance.

Localization and expression of thyroid hormone receptors in normal and neoplastic human thyroid

The aim of this study was to investigate the regional expression of thyroid hormone nuclear receptor forms (TRα and TRβ) and isoform (TRα1 and TRβ2) mRNAs in normal and neoplastic (benignant and malignant) human thyroid tissue. Tumor specimens from patients with thyroid carcinomas (papillary: 5 cases; follicular: 5 cases; anaplastic: 2 cases), thyroid follicular adenomas (7 cases) and tissue from normal thyroid glands (12 cases) were analyzed by in situ hybridization and semiquantitative RT-PCR for the expression of TRα1 and β, as well as for the isoform α2 that does not bind the hormone. In normal tissues, TRα2 was expressed at lower levels compared to TRα1 (α1/α2=4.3). In papillary and follicular carcinomas, the expression of TRα1 and TRβ did not change as compared with normal thyroid tissue and adenomas (0.87±0.15 SD vs 0.89±0.17 den-sitometric units, DU, and 0.15±0.02 vs 0.14±0.03 DU, respectively). However, the expression of TRα2 was significantly higher in differentiated carcinomas compared to normal thyroid tissue and adenomas (0.47±0.05 vs 0.20±0.05 DU, p<0.05) with α1/α2=1.4. In anaplastic carcinoma all TRs were absent. We concluded that both normal and pathological thyroid tissues, with the exception of anaplastic carcinoma, express all TRs in thyreocites and that differentiated thyroid carcinomas are associated in enhancing the expression of TRα2 mRNA.

T01-O-09 In vivo measurement of the human G-spot

The purpose of this study was to use ultrasonography to evaluate the anatomical variability of the urethrovaginal space (G-spot) in women with and without vaginal orgasm. 20 healthy, neurologically intact volunteers were recruited. All women underwent a complete urodynamic evaluation and those with clinical and urodynamic urinary incontinence, idiopathic detrusor overactivity, or micturition disorders, as well as post-menopausal women and those with sexual dysfunction were excluded. The reported experience of vaginal orgasm with or without orgasmic ejaculation was investigated. The urethrovaginal space thickness as measured by ultrasound was chosen as the indicator of urogenital anatomical variability. Designated evaluators carried out the measurements in a blinded fashion.The urethrovaginal space and distal, middle, and proximal urethrovaginal segments were thinner in women without vaginal orgasm. A direct correlation between the presence of vaginal orgasm and the thickness of urethrovaginal space was found. Women with a thicker urethrovaginal space were more likely to experience vaginal orgasm (r=0.884; p=0.015). A direct and significant correlation between the thickness of each urethrovaginal segment and the presence of vaginal orgasm / female ejaculation was found, with the best correlation observed for the distal segment (r=0.863; p

T05-P-01 Sexual symptoms in endocrine diseases

Not only the most frequent causes of endocrine sexual dysfunction, such as hypogonadism and hyperprolactinemia, but almost all extra-gonadal endocrinopathies (hyper-and hypothyroidism, hyper- and hypocortisolism, steroidal secreting tumors, etc.) may have a greater or lesser effect on sexual function. We analyzed scientific literature on the correlations between hormones and sexual behavior, analyzing the most important issue from a practical point of view. Our aim o was thus to summarize the sexual symptoms that may be observed with endocrine diseases. Hormones directly or indirectly regulate all human sexual functions (desire, erection/lubrication, ejaculation, orgasm). Some sexual symptoms may occur as a psychosomatic consequence of hormonal impairment. However, in other cases, endocrine failure may be generated by the psychosomatic involvement. The endocrinologist, as an expert in body chemistry, is ideally positioned to identify and evaluate the full range of medical, physical, and psychiatric problems disrupting sexual function.