Serum leptin levels and GHR-d3/fl gene polymorphism in acromegalic patients with thyroid nodules.

BACKGROUND: Acromegaly is a rare and serious syndrome that is commonly associated with pituitary neoplasms. Thyroid multinodular disease is a common finding in acromegaly. Leptin is a polypeptide hormone, and studies have shown that it can increase cell proliferation and inhibit apoptosis. OBJECTIVES: The aim of the study was to determine the relationship of serum leptin levels with certain blood parameters and determine if growth hormone receptor (GHR)-d3/fl gene polymorphism is associated with thyroid nodules in acromegalic patients. MATERIAL AND METHODS: A total of 24 acromegalic patients with or without thyroid nodules were included in the study. Gene polymorphisms and blood parameters were examined. RESULTS: A marked increase was observed in serum leptin concentration in acromegalic patients with thyroid nodules compared to patients without them (p < 0.05). GH levels were lower in patients without nodules than in patients with nodules (p < 0.05). Blood glucose levels were higher in patients with nodules compared to those without them (p < 0.05), and the presence of thyroid nodules was associated with decreased blood low-density lipoprotein (LDL) levels compared to patients without nodules (p < 0.05). A significant relationship was observed between growth hormone receptor (GHR)-d3/fl gene polymorphism and leptin levels in acromegalic patients with thyroid nodules (p < 0.001). CONCLUSIONS: These data from acromegalic patients indicate that thyroid nodules are associated with increased serum leptin, GH and blood glucose levels and with decreased LDL levels. GHR-d3/fl gene polymorphism status was strongly related to higher leptin levels.

IGF-1 gene polymorphism in obese patients with insulin resistance.

IGFs (Insulin like growth factors) are important regulators of pancreatic beta cell development, growth and maintenance. Mutations in the IGF genes have been found to be associated with diabetes mellitus, myocardial infarction obesity. These associations could result from changes in insulin secretion. We aimed to investigate IGF-1 gene polymorphism in obese patients with insulin resistance. We included 100 obese patients with insulin resistance 30 healthy subjects to study. At baseline examinations, antropometric measurements were done. Genomic DNA from the patients and controls were prepared. Thyroid function tests and serum IGFBP3 levels were similar between patients and controls whereas IGF, GH levels were significantly lower in obese patients. We categorized the IGF-1 (CA)19 polymorphism area into 3 groups as lower than 192 bp (group 1), 192-194 bp (group 2), and higher than 194 bp(group 3). Group 3 was more frequent in both obese and control groups. IGF-1 levels were also significantly lower in obese group (138.51 +/- 49.3) in than controls (218.14 +/- 69.15). IGF-1 levels were significantly lower in obese patients. The most frequent IGF-1 gen polymorphism allel is >194 bp in both obese insulin resistant patients and controls. IGF-1 levels and the other biochemical and hormonal parameters were similar in different genotype groups. The cause of lower IGF-1 levels in obese patients might be different from IGF-1 gene polymorphism and it may be insulin resistance.

Association of MDR1 C3435T polymorphism with bipolar disorder in patients treated with valproic acid.

P-glycoprotein (P-gp), an efflux transporter protein, is an ABC transporter encoded by the multidrug resistance 1 gene (MDR1, ABCB1). The common synonymous C3435T polymorphism in exon 26 is reported to associate with lower P-gp functional expression and drug uptake. Many extended pharmacogenomics, functional, and complex disease association studies focused mainly on this polymorphism. We investigated the association of exon 26 C3435T genetic variants of MDR1 gene with susceptibility to bipolar disorder and serum valproic acid concentration. Totally, 104 patients meeting DSM-IV criteria for bipolar disorder and 169 controls were admitted to the study. There was statistically significant difference between the genotypes of bipolar patients (CT 91.2%, TT 6.8%, and CC 2%) and controls (CT 52.7%, TT 26%, CC 21.3%) although their allelic distribution was similar. The serum valproic acid concentrations of the patients with CT, TT and CC genotypes were 72.92 +/- 20.55, 80.47 +/- 14.01 and 68.29 +/- 12.17 microg/ml, respectively, and there was no significant difference between the C3435T genotypes.

Effect of overdose zinc on mouse testis and its relation with sperm count and motility.

The purpose of this study was to investigate the effects of excessive zinc intake on the testes and on sperm count and motility in mice. Thirty Balb c mice were divided randomly into 3 groups of 10 animals in each. Group I acted as controls; group II was supplied with drinking water containing 1.5 g/100 mL Zn, and group III was supplied with drinking water containing 2.5 g/100 mL Zn. The animals were sacrificed after 3 wk supplementation and the epididymis and testis were quickly excised. A negative correlation between Zn dose and sperm count and motility was found. The sperm count in group III was significantly lower than in groups II and I (p<0.05). The sperm motility in group III was significantly lower than in the controls (p<0.05). Degenerative changes, including spermatic arrest, degeneration of seminiferous tubules, and fibrosis in interstitial tissue, were observed in group III animals. These results show that high doses of zinc significantly alter sperm motility.