Presentation on theme: "Biology 595EN Endocrinology October 28, 2003 Male Reproductive Endocrinology Kenneth L. Campbell Professor of Biology University of Massachusetts at Boston."— Presentation transcript:
Biology 595EN Endocrinology October 28, 2003 Male Reproductive Endocrinology Kenneth L. Campbell Professor of Biology University of Massachusetts at Boston
This presentation is made possible by a grant entitled “Shortcourses in Endocrinology at Minority Undergraduate Institutions” from the National Institute of General Medical Sciences (NIGMS) to The Minority Affairs Committee of the Endocrine Society
What are endocrine systems for? Endocrine Functions Maintain Internal Homeostasis Support Cell Growth Coordinate Development Coordinate Reproduction Facilitate Responses to External Stimuli
What are feedback systems? Feedbacks Generate Control Loops Negative These maintain hormonal balance & are often linked to homeostatic processes. If the multiplicative effect of the several links in a control loop is negative, the entire control loop is negative. Positive These cause physiologic changes in the system involved. If the multiplicative effect of the several links in a control loop is positive, the entire control loop is positive
How dynamic are these systems? Hormone, receptor, transducer & effector levels vary with time. Some change over short terms, others over long terms. Levels also vary with developmental stage, gender, & health status. testosterone_decline.gif After a248.e.akamai.net/.../pubs/mmanual_home/ illus/i232_1.gif
Outline of Male Reproduction 1. Adult anatomy 2. Embryogenesis 3. Sex determination 4. Hormonal controls 5. Puberty 6. Testicular anatomy 7. Meiosis 8. Spermatogenesis 9. Contraception 10. Aging
Adult Male Anatomy
Male Germ Cell Migration genital/genital_gifs/genital008-1.gif genital/genital_gifs/genital008-2all.gif
Sex Determination: Genetic
Sex Determination: Gonadal it-genital/genital_gifs/genital010-1.gif
Sperm Maturation Spermatozoa reach final shape in the testis, but they gain functional maturity while passing through the epididymus & female reproductive tract: activation of full motility, capacitation, in the vagina & cervix; final fertilizing ability after the acrosome reaction, usually near the egg.
Male Contraception Barriers condoms Vasectomy Hormones peripheral androgens +/- LHRH antagonists or agonists
Male Serum Hormone Age Profiles Male Aging & Reproductive Senescence
The ratio T/SHBG is the FAI, a Measure of free T. Adrenal androgens like DHEAS also decline with age.
Low Fertility in Gainj vs Other Groups
How is prolactin controlled?
FSH in Gainj Men
LH in Gainj Men
Many Gainj Men are Infertile
Support from: NSF, Umass/Boston, Sandia National Labs, Hybritech, Quidel, Monoclonal Antibodies Inc.Acknowledgements Gainj Project The Gainj People Rees Midgley Al Hermalin Lora Myers Jim Wood Pat Johnson Ila Maslar Diana Lai Sam Refetoff Peter Smouse Peter Heywood Michael Alpers Brian Davison Yan Ren Lynne Shinto Diane Drinkwater Darryl Holman Bettina Shell Related Studies Kathy O’Connor Coralie Munro Susannah Barsom Ellie Brindle Cheryl Stroud Kai Orton Jodiann Thompson Yefim Proshchitskiy Yelena Filipova Matt Lopresti Oliver Schultheiss Cheryl Frederick Steve Monfort Malcolm Potts David McClelland (dec) Turkana Project All Turkana Subjects Mike Little Paul Leslie Ben Campbell Dhanesh Dookhran Kathy Whiteman Alexandra Evindar William Lukas Sandra Gray Jeanine Quigley Christine Sekadde -Kigondu Leah Kirumbi (*in the lab at UMB)