Biomaterial Database

Absence of 5 alpha-reductase activity in the gubernaculum during descent of the fetal pig testis. 1993

C F Heyns, and R Tate, and N S Sargent, and F K Habib, and G D Chisholm

Department of Surgery/Urology, University of Edinburgh, Western General Hospital, Scotland.

To evaluate the hypothesis that testicular descent is mediated by the action of high local concentrations of dihydrotestosterone in the gubernaculum, testis, or epididymis, we obtained tissues from 30 male pig fetuses between 63 and 101 days of gestation. We assayed the 5 alpha-reductase activity in homogenates of pooled tissue by following the conversion of (3H)testosterone to (3H)dihydrotestosterone. The 5 alpha-reductase activity in the urethra and prostate increased prior to and during, but decreased after, the period of testicular descent. The 5 alpha-reductase activity in the gubernaculum remained constant throughout gestation and was not significantly higher than the background activity found in umbilical cord, testis plus epididymis, striated thigh muscle and heat inactivated samples of prostate and urethra. Prior to testicular descent, the 5 alpha-reductase activity was approximately 60 to 300 times higher in the urethra than in the gubernaculum, and approximately 20 to 55 times higher in the prostate than in the gubernaculum. These findings indicate that local conversion of testosterone to dihydrotestosterone in the gubernaculum or epididymis does not play a role in the mediation of testicular descent in the pig fetus.

UI	MeSH Term	Description	Entries
D008022	Ligaments	Shiny, flexible bands of fibrous tissue connecting together articular extremities of bones. They are pliant, tough, and inextensile.	Interosseal Ligament,Interosseous Ligament,Interosseal Ligaments,Interosseous Ligaments,Ligament,Ligament, Interosseal,Ligament, Interosseous
D008297	Male		Males
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D010088	Oxidoreductases	The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)	Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D011467	Prostate	A gland in males that surrounds the neck of the URINARY BLADDER and the URETHRA. It secretes a substance that liquefies coagulated semen. It is situated in the pelvic cavity behind the lower part of the PUBIC SYMPHYSIS, above the deep layer of the triangular ligament, and rests upon the RECTUM.	Prostates
D005333	Fetus	The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.	Fetal Structures,Fetal Tissue,Fetuses,Mummified Fetus,Retained Fetus,Fetal Structure,Fetal Tissues,Fetus, Mummified,Fetus, Retained,Structure, Fetal,Structures, Fetal,Tissue, Fetal,Tissues, Fetal
D005865	Gestational Age	The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated from the onset of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization. It is also estimated to begin from fertilization, estrus, coitus, or artificial insemination.	Embryologic Age,Fetal Maturity, Chronologic,Chronologic Fetal Maturity,Fetal Age,Maturity, Chronologic Fetal,Age, Embryologic,Age, Fetal,Age, Gestational,Ages, Embryologic,Ages, Fetal,Ages, Gestational,Embryologic Ages,Fetal Ages,Gestational Ages
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013737	Testis	The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.	Testicles,Testes,Testicle