Contraception — retrospect and prospect

Harper, M. J. K.

doi:10.1007/978-3-0348-7098-6_4

Cited by 7 publications

(2 citation statements)

References 566 publications

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“…The calculated rates fall within the range that is believed necessary for fertility control by sustained administration of the more potent progestins, e.g., norethindrone and norgestrel (16). Furthermore, while the duration of release (loadhate) is independent of capsule length and not very sensitive to changes in the outside diameter-inside diameter ratio, manipulation of the percent dispersion provides a means of varying the duration from several months to years.…”

Section: The Initial Curvature Of the Fig I Plots ( T < 15 Min) Is Imentioning

confidence: 54%

Sustained Drug Delivery Systems II: Factors Affecting Release Rates from Poly(ε-caprolactone) and Related Biodegradable Polyesters

Pitt

Gratzl

Jeffcoat

et al. 1979

Journal of Pharmaceutical Sciences

201

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Section: The Initial Curvature Of the Fig I Plots ( T < 15 Min) Is Imentioning

confidence: 54%

Sustained Drug Delivery Systems II: Factors Affecting Release Rates from Poly(ε-caprolactone) and Related Biodegradable Polyesters

Pitt

Gratzl

Jeffcoat

et al. 1979

Journal of Pharmaceutical Sciences

201

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“…The pattern of ovarian steroid secretion close to the time of ovulation prepares the oviduct for the reception and maturation of gametes (male and female) and thereafter for fertilisation and early embryonic development. Treatment of a patient or animal with ovarian steroid hormones invariably perturbs the physiological functions of the oviduct and can compromise fertilisation and/or embryonic development (Harper, 1977; Hunter, 1980).…”

Section: Evolutionary Perspectivementioning

confidence: 99%

Components of oviduct physiology in eutherian mammals

2011

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Recalling the evolutionary sequence of development first of gonad and subsequently of oviducts, ovarian endocrine regulation of all known components of oviduct physiology is reviewed. Ovaries not only influence oviducts via the systemic blood circulation, but also locally by counter-current transfer of relatively high concentrations of steroid hormones and prostaglandins between the ovarian vein and oviduct branch of the ovarian artery. The efficiency and impact of such counter-current transfer is greatest around the time of ovulation, the transfer process receiving further inputs from hormones present in peritoneal fluid. Classical oviduct physiology is summarised, and the potential molecular consequences of temperature gradients within the duct lumen examined. At ovulation, an oocyte-cumulus complex is displaced in minutes from the follicular surface to the site of fertilisation at the ampullary-isthmic junction of the oviduct. This rapid initial phase is contrasted with the subsequent slow progression of embryos to the uterus in days, still encompassed within a zona pellucida. Regarding transport of spermatozoa, the formation of a pre-ovulatory reservoir in the caudal portion of the oviduct isthmus is noted, with suppression of motility and sperm-head binding to epithelial organelles acting to maintain fertilising ability. Completion of capacitation is prompted shortly before ovulation, predominantly by Ca(2+) influx into bound spermatozoa. A controlled release of spermatozoa coupled with their hyperactivation results in initial sperm:egg ratios at the site of fertilisation close to unity, thereby avoiding the pathological condition of polyspermy. Both the oviduct milieu and embryonic development are influenced by paracrine activity of follicular granulosa cells released at ovulation and remaining in suspension in the vicinity of the oocyte or embryo. These cells may amplify early pregnancy signals from a zygote to the endosalpinx. Beneficial effects of the oviduct on domestic animal embryos are contrasted with anomalies arising as a consequence of in vitro culture. Primate embryos do not require exposure to an oviduct for normal development, perhaps due to overlapping compositions of endosalpingeal and endometrial secretions. Additionally, primate endometrial secretions may be modified by viable gametes or an embryo in the presence of a cumulus cell suspension.

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Bor und spezielle Borverbindungen

Kliegel¹

1980

BOR in Biologie, Medizin Und Pharmazie

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Contraception — retrospect and prospect

Cited by 7 publications

References 566 publications

Sustained Drug Delivery Systems II: Factors Affecting Release Rates from Poly(ε-caprolactone) and Related Biodegradable Polyesters

Sustained Drug Delivery Systems II: Factors Affecting Release Rates from Poly(ε-caprolactone) and Related Biodegradable Polyesters

Components of oviduct physiology in eutherian mammals

Bor und spezielle Borverbindungen

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