Biomaterial Database

Androgen metabolism in the male hamster--1. Metabolism of testosterone in the pituitary gland and in the brain of animals exposed to different photoperiods. 1987

P Negri-Cesi, and F Celotti, and R C Melcangi, and L Martini

It is known that the metabolism of testosterone in the brain and in the anterior pituitary is different in mammalian and in photoperiodic avian species. In many mammalian species, testosterone is mainly metabolized to 5-alpha-reduced compounds (e.g. 17-beta-hydroxy-5-alpha-androstan- 3-one, 5 alpha-DHT and 3-alpha,17-beta-dihydroxy-5-alpha-androstane, 5-alpha,3-alpha-diol) and, to a smaller extent, to 4-androstene-3,17-dione (androstenedione), while in birds, androstenedione is the main testosterone metabolite and the conversion to the 5-alpha-reduced compounds is quantitatively negligible. In avian species, testosterone is also converted to 5-beta-reduced steroids (mainly 17-beta-hydroxy-5-beta-androstan-3-one, 5-beta-DHT and 3-alpha,17-beta-dihydroxy-5-beta-androstane, 5-beta,3-alpha-diol), and there is also evidence that in these species testosterone metabolism in the central structures may be influenced by the photoperiod. Since the hamster is a mammal whose reproductive cycle is controlled by day length, it has been analyzed whether: (a) the central structures of the hamster (cerebral cortex, hypothalamus and anterior pituitary) metabolize testosterone in vitro following a mammalian (5-alpha-reduced derivatives) or an avian (androstenedione and 5-beta-reduced compounds) pattern; and (b) the metabolism of testosterone in the same structures may be modified by the exposure to different photoperiods (LD 14:10 or LD 8:16). The present data indicate that no one of the hamster structures examined produces the 5-beta-reduced derivatives. Moreover, the formation of the 5 alpha-DHT is quantitatively low, and is not affected by the photoperiod. In contrast, androstenedione is formed in quite high yields and the exposure of the animals to 60 days of short photostimulation increases the formation of this steroid in the pituitary gland, but not in the brain structures. From these data, it appears that the central structures of the hamster metabolize testosterone with a pattern which is intermediate between that of birds and mammals.

UI	MeSH Term	Description	Entries
D007986	Luteinizing Hormone	A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.	ICSH (Interstitial Cell Stimulating Hormone),Interstitial Cell-Stimulating Hormone,LH (Luteinizing Hormone),Lutropin,Luteoziman,Luteozyman,Hormone, Interstitial Cell-Stimulating,Hormone, Luteinizing,Interstitial Cell Stimulating Hormone
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D008297	Male		Males
D008647	Mesocricetus	A genus in the order Rodentia and family Cricetidae. One species, Mesocricetus auratus or golden hamster is widely used in biomedical research.	Hamsters, Golden,Hamsters, Golden Syrian,Hamsters, Syrian,Mesocricetus auratus,Syrian Golden Hamster,Syrian Hamster,Golden Hamster,Golden Hamster, Syrian,Golden Hamsters,Golden Syrian Hamsters,Hamster, Golden,Hamster, Syrian,Hamster, Syrian Golden,Syrian Hamsters
D010903	Pituitary Gland, Anterior	The anterior glandular lobe of the pituitary gland, also known as the adenohypophysis. It secretes the ADENOHYPOPHYSEAL HORMONES that regulate vital functions such as GROWTH; METABOLISM; and REPRODUCTION.	Adenohypophysis,Anterior Lobe of Pituitary,Anterior Pituitary Gland,Lobus Anterior,Pars Distalis of Pituitary,Adenohypophyses,Anterior Pituitary Glands,Anterior, Lobus,Anteriors, Lobus,Lobus Anteriors,Pituitary Anterior Lobe,Pituitary Glands, Anterior,Pituitary Pars Distalis
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster
D000735	Androstenedione	A delta-4 C19 steroid that is produced not only in the TESTIS, but also in the OVARY and the ADRENAL CORTEX. Depending on the tissue type, androstenedione can serve as a precursor to TESTOSTERONE as well as ESTRONE and ESTRADIOL.	4-Androstene-3,17-dione,delta-4-Androstenedione,4 Androstene 3,17 dione,delta 4 Androstenedione
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