A cell frequently utilizes glucose as a fuel of energy and a major substrate of lipid and protein syntheses. A regulation of glucose movement into and out of the cells is precisely controlled by cooperative works of passive and sodium‐dependent active processes. At least 13 glucose cotransporter (Slc2a, GLUT) isoforms involve in passive movement of glucose in cells. The efferent ductules (EDs) play in a number of important functions for maintenance of male fertility. In the present study, using real‐time PCR analysis, we determined gene expression of five Slc2a isoforms in the EDs. In addition, we compared expression levels of these Slc2a isoforms according to postnatal development ages, 1 week, 2 weeks, 1 month, and 3 months. Results from the current study showed that expression of Slc2a1, Slc2a3, and Slc2a5 mRNAs reached the highest levels at 1 month of age, followed by a transient decrease at 3 months of age. In addition, the level of Slc2a4 mRNA reminded at steady until 1 month of age and was significantly reduced at 3 months of age, whereas the highest level of Slc2a 8 mRNA was detected at 2 weeks of age. Data from the present study indicate a differential expression of various Slc2a isoforms in the ED according to postnatal ages. Thus, it is believed that glucose movement through the epithelial cells in the ED would be regulated by the coordinated manner among Slc2a isoforms expressed at a given age.

Mammalian spermatogenesis occurs in a precise and coordinated manner in the seminiferous tubules. One of the attempts to understand the detailed biological process during mammalian spermatogenesis at the molecular level has been to identify the testis specific genes followed by study of the testicular expression pattern of the genes. From the subtracted cDNA library of rat testis prepared using representational difference analysis (RDA) method, a complimentary DNA clone encoding type III member of a DnaJ family protein, DnaJC18, was cloned (GenBank Accession No. DQ158861). The fulllength DnaJC18 cDNA has the longest open reading frame of 357 amino acids. Tissue and developmental Northern blot analysis revealed that the DnaJC18 gene was expressed specifically in testis and began to express from postnatal week 4 testis, respectively. In situ hybridization studies showed that DnaJC18 mRNA was expressed only during the maturation stages of late pachytene, round and elongated spermatids of adult rat testis. Western blot analysis with DnaJC18 antibody revealed that 41.2 kDa DnaJC18 protein was detected only in adult testis. Immunohistochemistry study further confirmed that DnaJC18 protein, was expressed in developing germ cells and the result was in concert with the in situ hybridization result. Confocal microscopy with GFP tagged DnaJC18 protein revealed that it was localized in the cytoplasm of cells. Taken together, these results suggested that testis specific DnaJC18, a member of the type III DnaJ protein family, might play a role during germ cell maturation in adult rat testis.

Connexin (Cx) is a complex which allows direct communication between neighboring cells via exchange of signaling molecules and eventually leads to functional harmony of cells in a tissue. The initial segment (IS) is an excurrent duct of male reproductive tract and expression of numerous genes in the IS are controlled by androgens and estrogens. The effects of these steroid hormones on gene expression in the IS during postnatal development have not extensively examined. The present research investigated expressional modulation of Cx isoforms in the IS by exogenous exposure to estrogen agonist, estradiol benzoate (EB), or androgen antagonist, flutamide (Flu), at weaning age. Two different doses of EB or Flu were subcutaneously administrated in 21-day old of male rats, and expressional changes of Cx isoforms in the adult IS were analyzed by quantitative real-time PCR. Treatment of a low-dose EB (0.015 μg/kg body weight) resulted in an increased expression of Cx31 gene and a decreased expression of Cx37 gene. A high-dose EB (1.5 μg/kg body weight) treatment caused an increase of Cx31 gene expression. Increased levels of Cx30.3 and Cx40 transcripts were observed with a low-dose Flu (500 μg/kg body weight) treatment. Treatment of high-dose Flu (50 mg/kg body weight) led to expressional increases of Cx30.3, 40, and 43 genes. Our previous and present findings suggest differential responsiveness on gene expression of Cx isoforms in the IS by androgens and estrogens at different postnatal ages.

Direct cell-cell communication through connexin (Cx) complexes is a way to achieve functional accordance of cells within a tissue or an organ. The initial segment (IS), a part of the epididymis, plays important roles in sperm maturation. Steroid hormones influence on expression of a number of genes in the IS of adult animals. However, developmental effect of sex hormones on the gene expression in the IS has not been examined. In this study, estradiol benzoate (EB, an estrogen agonist) or flutamide (Flu, an androgen antagonist) was exogenously administrated at 1 week of postnatal age, and expressional changes of Cx genes in the IS were determined at 4 months of age by a quantitative real-time PCR analysis. Treatment of EB at 0.015 mg/kg body weight (BW) increased expression of Cx30.3, 31.1, and 43 genes. However, treatment of 1.5 mg EB/kg BW resulted in expressional decreases of Cx31, 32, and 45 genes and caused increases of Cx30.3 and 43 gene expression. Significant decreases of Cx31, 31.1, 32, 37, and 45 gene expression were detected with a treatment of 500 mg Flu/kg BW, while expression of Cx43 gene was significantly increased with a treatment of 500 mg Flu/kg BW. A treatment of 50 mg Flu/kg BW led to significant increases of Cx30.3, 32, 37, 40, and 43 gene expression. These findings imply that exogenous exposure of steroidal hormones during the early developmental period would result in aberrant expression of Cx genes in the adult IS.

외과적으로 정소를 제거하는 물리적 거세와 약물을 이용한 화학적 거세는 의학적 치료나 연구의 목적으로 다양하게 사용되고 있다. 최근 흰쥐 정소에 20%의 고장성 식염수를 직접 주사할 경우 혈중 테스토스테론 수준이 외과적 거세와 유사한 수준까지 저하되어 화학적 거세 상태에 들어감이 보고되었다. 그러나 고장성 식염수를 정소에 직접 주사함으로서 나타나는 염증반응으로 인해, 안전성에 대한 우려가 제기되고 있다. 본 연구는 기존 연구에서 보다 낮은 농도의 식염수를 주사하여 농도에 따른 효과와 효용성을 조사하고자, 조직학적 변화를 확인하였다. 성체 수컷 흰쥐에 멸균한 5%, 10%, 20% 생리 식염수를 정소 당 500 ㎕씩 직접 주사하여 농도별 식염수 주사군(saline-injection)과 대조군(control)로 분류하고, 실험군의 체중을 측정하여 기록하였다. 주사 후 1주 뒤에 모든 동물들의 체중을 측정한 후 희생하였다. 각 실험군의 체중 변화와 조직 무게 변화를 비교하였고, 생식기관인 정소, 부정소, 저정낭, 전립선은 Hematoxylin & Eosin 염색법을 사용하여 조직학적 변화를 관찰하였다. 정소 무게는 5% 주사군과 20% 주사군에서 유의하게 감소하였고, 10% 주사군에서는 대조군에 비해 감소하였으나 유의하지는 않았다. 부정소의 경우 20% 주사군에서 매우 유의하게 감소하는 양상을 보였고, 저정낭의 무게는 10% 주사군과 20% 주사군에서 유의하게 감소하였다. 전립선의 경우 20% 주사군에서만 유의하게 감소하였다. 기타 조직에서는 면역기능을 담당하는 비장의 무게가 10% 주사군에서 유의하게 증가하는 양상을 보였고, 신장은 20% 주사군에서 유의하게 감소하였다. 조직학적 관찰 결과, 10% 주사군과 20% 주사군의 정소에서 전체적인 형태 변화와 세정관의 손상을 확인할 수 있었고, 부정소는 20% 주사군의 경우 도관 내 정자가 거의 관찰되지 않았다. 저정낭의 경우 농도의존적으로 내강이 감소하며 위축되는 양상을 보였다. 전립선은 20% 주사군에서 확연한 내강의 감소와 도관의 격리됨을 확인하였다. 본 연구는 기존에 보고된 정소 내 식염수 주사모델의 독성 문제가 제기됨에 따라 보다 낮은 농도에서의 효용성을 조사하고자 한 것이다. 생식 기관의 조직학적 조사를 통해 비교적 낮은 농도의 식염수 주사모델이 기존의 20% 식염수 주사 모델과 유사한 효과를 나타냄을 확인하였다. 그러나 물리적, 화학적 거세모델과 유사한 거세 효과를 유발할 수 있는지에 대해서는 보다 심층적인 연구가 필요할 것으로 사료된다.

지구상의 모든 생명체들은 자신의 생존과 종의 영속성을 보장하기 위해 우호적이지 않은 환경 변화에 대응하기 위한 효과적인 전략을 발전시켜왔다. 그 결과, 생명체들은 환경요인들의 변화에도 불구하고 체내 생리적 환경의 역동적인 평형, 즉 항상성(homeostasis)을 유지해 나간다. 스트레스는 항상성을 위협하는 정서적 그리고 물리적 반응이다. 스트레스는 일시적일 뿐만 아니라 거의 영구적인 영향을 개체에 줄 수 있는데, 특히 출생전 스트레스는 유전 코드의 변

세로토닌(serotonin, 5-HT)은 아민류 가운데 카테콜아민과 더불어 중요한 체네 생리 및 행동 조절을 담당하는 신경 전달물질이다. 특히 'Prozac'으로 잘 알려진 항우울제는 5-HT의 세포내 재흡수를 선택적으로 억제하는 약물(selective serotonin reuptake inhibitor, SSRI)로써 광범위하게 사용중인 약물인데, 알려진 부작용으로 사정 능력의 변화가 관찰된다. 이는 5-HT에 의한 성 행동 또는 성 기능 조절기작이