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L Devoto

Publications and source records attributed to L Devoto.

63 records · Page 4Linked to original sources
PubMed1981

Estradiol dehydrogenase activity in the Fallopian tube during the normal menstrual cycle.

Simultaneous determinations of 17 beta-estradiol dehydrogenase activity (17 beta-HSDH) and of estradiol (E2), estrone (E1), and progesterone (P) were made in homogenates of human tubal tissue. The oviducts were obtained from 16 multi-parous normal women who requested sterilization; surgery was performed at different phases of the menstrual cycle. A significant decrease of E2 concentration with a concomitant increase of E1 was observed in the secretory phase of the cycle. The activity of 17 beta-HSDH was highest in the early secretory phase of the cycle with a significant difference (p less than 0.05) from the proliferative phase values. The results support the concept, that the activity of 17 beta-HSDH in the oviduct is regulated by progesterone.

17-Hydroxysteroid Dehydrogenases↗
PubMed1980

Unconjugated steroids in the fallopian tube and peripheral blood during the normal menstrual cycle.

Daily plasma samples were obtained from 22 high-parity normal women beginning on day 9 of the menstrual cycle. At varying times in the cycle, salpingectomy was performed and the excised tube was divided into isthmic, ampullary, and fimbrial segments. Simultaneous determinations of 17 beta-estradiol (E2), estrone (E1), and progesterone (P) in plasma and tubal tissue were carried out by specific radioimmunoassay. The highest ratio for E2 tissue to E2 plasma was seen at the time of the E2 peak. The E2 concentrations in the three anatomical segments of the fallopian tube during the late proliferative phase were significantly (P less than 0.05) higher than those during the early proliferative and late postovulatory periods. A significant (P less than 0.05) increase in P concentration was seen in both plasma and oviductal tissue after ovulation. The tubal tissue to plasma ratio had a tendency to decrease during the secretory phase, indicating a limited uptake of P during the secretory phase. The plasma levels of esterone were almost constant during the normal menstrual cycle. The highest concentration of E1 was seen in the fimbriae (254 +/- 71 pg/gm and ampulla (326 +/- 75 pg/gm during the early secretory phase of the cycle. The possible role of E1 during this crucial time of oviductal physiology is considered.

Adult↗
PubMedDate not supplied

Leptin and reproduction.

Leptin, the product of the ob gene, is a small peptide molecule synthesized by white adipocytes with an important role in the regulation of body fat and food intake. Leptin and leptin receptor mRNA were first detected in the brain and hypothalamus but now their ubiquitous presence has been demonstrated. Leptin receptor signal transduction involves the activation of signal transducer and activator of transcription (STAT)-3, a member of the transcription family of proteins. Leptin is regulated by hormones and cytokines, interleukin-1, tumour necrosis factor-alpha and transforming growth factor-beta, linking this molecule with the inflammatory response. In addition, emerging evidence has demonstrated that this molecule is related to reproductive function. This small protein is present in the ovary and decidua, in mature oocytes and during embryonic development and trophoblast invasion. Animal models have demonstrated that leptin-deficient ob/ob mice are sterile; however, fertility can be restored by exogenous leptin. In addition, embryos implanted in STAT-3-deficient mice degenerate rapidly and are the target disruption of STAT-3-provoked embryonic lethality. Leptin acts as a novel placental hormone participating in the control of fetal growth and development. Leptin could be a modulator for invasive features of cytotrophoblast cells. We postulate that leptin may have an autocrine/paracrine role in human implantation and placentation.

Animals↗