Mammal: hairy endothermic vertebrate that suckles its offspring (lactation)

Eutherian: placental mammal; gives birth to a sexually-differentiated fetus

Metatherian: pouched mammal (marsupials); gives birth to a "living" (viviparous) young in the embryonic stage (ie., not sexually-differentiated)

Prototherian: egg-laying (oviparous) mammal (monotremes) (eg., duck-billed platypus, spiny anteater)

Hormone: chemical messenger synthesized by an endocrine gland (ductless) that is secreted directly into the circulation to act on a genetically-responsive target (ie., contains complementary receptors)

Neurohormone: an endocrine messenger of the nervous (eg., hypothalamic) system

Tropic: hormone that has its target site on an endocrine gland

Exocrine: secretion of a product (eg., gametes) into a duct

Endocrine doctrine: the principle introduced by Berthold (1849) that blood-borne agents (hormones) can utilize the circulation as a medium for communication to regulate physiological functions at a distant site; his work was based on the "remove-and-replace" (castration > treatment with testicular extract > reestablishment of sexual activity) experimental method that became the foundation of classical endocrine research

PAP smear: a test (named after Papanicolaou) by which cervical cells are removed with a swab, transferred onto a microscope slide, stained, and examined for the presence of cancer (vaginal cytological smears can likewise be used to diagnose stages of the reproductive cycle)

Hypophysectomy: surgical removal of the pituitary (hypophysis) gland

Long-loop feedback: peripheral control of a hormone by an end-product of its action; can be negative (eg., sex steroid down-regulation of GnRH production, inhibition of FSH secretion by inhibin) or positive (estradiol induction of the preovulatory release of GnRH)

[short-loop feedback = pituitary gland > hypothalamus]

Prostaglandins: bioactive metabolites of arachidonate

NSAIDs: nonsteroidal antiinflammatory drugs; prostaglandin inhibitors

Second messengers: modulate intracellular responses of (membrane-active) hormones/local mediators (eg., cAMP)

Radioimmunoassay: sensitive procedure to measure hormones based on the principle of competition between a nonradioactive and radiolabeled hormone for binding to an antibody specific to the hormone (decreased binding of "hot" hormone = increased amount of [known] standard or [unknown] sample)

Transgenic: containing exogenous genetic material that becomes incorporated into the genome and is transmitted in the progeny; a transgenic animal can be produced by injecting DNA into zygotes or young embryos or by exposing (permeabilized) embryonic stem cells to DNA or an infective virus; transfection is used to produce large quantities of specific molecules (eg., growth hormone); the procedure is still very inefficient

 

Fallopius: oviducts; de Graaf: preovulatory follicle; von Leydig: testicular interstitial cells; Sertoli: epithelial cells of the seminiferous tubule; Wolff: embryonic male (Wolffian) duct system; M�ller: embryonic female (Mullerian) duct system; Rathke: Rathke's pouch - the embryonic predecessor of the adenohypophysis

 

Pineal gland: due to its geographic location (roof of the III ventricular) was thought to be the "seat-of-the-soul"; its functional significance was discounted during the early part of the 1900s; the photosensory/melatonin-producing role of the pineal gland in the regulation of seasonal reproductive activity was established during the 1960s/70s

Pituitary gland: was generally regarded as the "waste disposal" area of the brain until the pioneering hypophysectomy studies (1912-1936) of Philip Smith; the pituitary was thus elevated to the status of "master gland" - only to be superseded by the hypothalamus

 

Hierarchy of reproductive control: hypothalamus > anterior pituitary > gonads > reproductive tract, hypothalamic-pituitary axis (feedback)

[male ducts = epididymis, vas deferens, urethra; accessory glands = seminal vesicles, prostate, bulbourethral; female tubular organs = oviducts, uterus, cervix, vagina]

 

Hormonal classifications: steroid, peptide/protein (most complex = gonadotropins)

 

Bioassays - GnRH: FSH/LH secretion; FSH: ovarian weight augmentation; LH: ovarian ascorbate depletion; hCG: ovulation; prolactin: increased weight of crop sacs; progesterone: uterine gland proliferation; testosterone: increased weight of male accessory glands, comb growth; estradiol: cornification of vaginal epithelium; inhibin: inhibition of FSH secretion; relaxin: relaxation of the interpubic ligament, cervical dilation; oxytocin/prostaglandins: smooth muscle contraction; MIH: Mullerian duct regression

 

Y chromosome: sex determination in mammals

 

Most effective methods of human fertility control: 1) vasectomy/tubal ligation (sterilization); 2) steroid hormones

Most popular methods of human fertility control: sterilization (married); oral contraceptives (unmarried)

Hormonal contraceptive options: Depo-Provera (three month progestin injection); Implanon (three year progestin implant); NuvaRing (three week combination intravaginal device); OrthoEvra (3 x one week combination transdermal patch); Seasonale/Seasonique (daily 12 weeks-on oral combination); Yaz, Loestrin 24 Fe (24 days-on/4 days-off oral combination); Natazia (26 days-on/2 days-off oral combination); Lybrel (continuous daily oral combination); Mini-pill (28 day oral progestin); Emergency pills � Plan B (oral progestin), Ella (oral antiprogestin)

Experimental contraceptive approaches: vas/tubal microvalves and implants; long-acting injectable synthetic steroids for males; GnRH analogs; antimicrobial spermicides; vaccines against hCG and sperm/zona antigens 

 

IUD: side-effects have limited the use in the US; however, the method is very effective and requires no long-term conscious effort; it remains a significant tool in global population control

 

Advantages of AI: rapid genetic progress (contributed by the male [XY] genotype) and control of sexually-transmitted diseases in farm animals; overcome cervical factor infertility and oligospermia in human beings

 

Elective abortions in the US: are permitted during the first trimester of pregnancy with specific state restrictions regarding residence, parental/spousal notification, and waiting period; procedures performed after the first trimester are only allowed in cases of fetal defect and(or) physical/emotional hazard to the mother

 

Abortifacients: prostaglandins, oxytocin, estrogens, antiprogestins (eg., RU486/mifepristone)

 

Major nondisease causes of reduced reproductive efficiency - beef cattle: extended postpartum interval, fetal/calf deaths; dairy cattle: lack of detected estrus/infertile service, cystic ovaries; sheep: low lambing rate, seasonality; swine: embryonic mortality, anestrus, male infertility; horse: seasonality, long estrous period, male infertility

 

Human infertility: approximately 15% of the population - due to male factor (40%), pelvic factor (30%), ovarian factor (15%), cervical factor (15%)

 

IVF-ET: tubal blockage, unexplained infertility; follicular growth stimulation > ovulation induction > oocyte recovery > IVF > intrauterine transplantation

Danger: ovarian hyperstimulation, multiple pregnancy, ovarian cancer risk?

ET in farm animals: takes advantage of genetic progress made by the female (XX) genotype

 

Some potential benefits of embryonic manipulations: species propagation by cloning (eg., embryo-splitting or via a dedifferentiated adult cell/nuclear transfer); sexing; transgenics - increased growth, fertility, resistance to disease/stress, production of valuable pharmaceuticals; creation of stem cells for treatments of tissue/organ dysfunctions