Seasonal pattern of ovarian growth and interrelated changes in plasma steroid levels, vitellogenesis, and oviductal function in the adult female soft-shelled turtle Lissemys punctata punctata

1996 ◽  
Vol 74 (2) ◽  
pp. 303-311 ◽  
Author(s):  
Supriti Sarkar ◽  
B. R. Maiti ◽  
N. K. Sarkar
Keyword(s):  
Reproductive Cycle ◽  
Plasma Levels ◽  
Seasonal Pattern ◽  
Plasma Progesterone ◽  
Annual Peak ◽  
Ovarian Growth ◽  
Preparatory Phase ◽  
17Β Estradiol ◽  
Winter Hibernation ◽  
Estradiol Concentration

The female reproductive cycle of the freshwater soft-shelled turtle Lissemys punctata punctata was studied by correlating ovarian growth with changes in plasma levels of steroids (17β-estradiol and progesterone), vitellogenic indices (calcium, lipid, protein, and cholesterol), and oviductal changes (growth, glycogen, and peroxidase levels). Ovarian growth starts after winter hibernation, proceeds slowly during the preparatory phase (March–June), becomes rapid in the recrudescent phase (July), and peaks in the breeding phase (August–September). Subsequently, the follicles undergo atresia in the regressive phase (October–November), which is followed by the quiescent phase (December–February) marked by negligible ovarian growth. Plasma levels of 17β-estradiol and vitellogenic indices reflect the same pattern of change as ovarian growth. The plasma progesterone concentration remains low throughout the reproductive cycle, except that the titre reaches a postovulatory peak and then declines prior to oviposition. Oviductal mass and glycogen and peroxidase concentrations correspond to changes in plasma estradiol concentration. The findings indicate that the seasonal reproductive cycle of L. p. punctata is characterized by a single annual peak of ovarian growth and estrogen secretion compared with a double peak recorded in other single-clutch turtles.

Delayed ovulation and parturition in a viviparous alpine lizard (Niveoscincus microlepidotus): morphological data and plasma steroid concentrations

2002 ◽  
Vol 14 (1) ◽  
pp. 43 ◽  
Author(s):  
J. E. Girling ◽  
S. M. Jones ◽  
R. Swain
Keyword(s):  
Reproductive Cycle ◽  
Early Pregnancy ◽  
Post Partum ◽  
Maximum Size ◽  
Morphological Data ◽  
Monthly Basis ◽  
Plasma Progesterone ◽  
Plasma Oestradiol ◽  
Winter Hibernation ◽  
Detailed Picture

The southern snow skink, Niveoscincus microlepidotus, exhibits an unusual biennial reproductive cycle with an extended gestation period of approximately 1 year. Morphological data were gathered on a monthly basis, providing a detailed picture of the reproductive cycle. Vitellogenesis begins in spring, immediately after parturition. Maximum follicular diameter is reached before the winter hibernation period and ovulation occurs the following spring. Embryos are fully developed and reach maximum size by early autumn. Yolk reserves are depleted before winter. Birth of between one and four young occurs the following spring. Plasma progesterone concentrations are low (2.7 ± 0.9 ng mL–1) in post-partum females, begin to rise in autumn in vitellogenic females and peak (38.5 ± 7.9 ng mL–1) in pre-ovulatory females after hibernation. Concentrations are high (15.4 ± 5.9 ng mL–1) in early pregnancy and decline to basal levels before winter and well before birth in spring. Plasma oestradiol concentrations peak during vitellogenesis (1.0 ± 0.3 ng mL–1) and decline to basal levels during pregnancy (0.2 ± 0.03 ng mL–1). A second oestradiol peak occurs before parturition (0.7 ± 0.2 ng mL–1). Thus, functional completion of vitellogenesis and gestation is achieved by autumn in successive years. The mechanisms that defer ovulation and parturition by a further six months are unknown.

scholarly journals Proliferative and Apoptotic Pathways in the Testis of Quail Coturnix coturnix during the Seasonal Reproductive Cycle

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1729
Author(s):  
Sara Falvo ◽  
Luigi Rosati ◽  
Maria Maddalena Di Fiore ◽  
Federica Di Giacomo Russo ◽  
Gabriella Chieffi Baccari ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Second Messengers ◽  
Reproductive Period ◽  
Annual Reproductive Cycle ◽  
Coturnix Coturnix ◽  
Immunohistochemistry Analysis ◽  
17Β Estradiol ◽  
Apoptotic Pathways ◽  
Camp And Cgmp ◽  
Activation Phase

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E2) and androgens are higher during the reproductive period compared to the non-reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2-induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt-1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non-reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt-1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad.

scholarly journals Phoenixin as a New Target in the Development of Strategies for Endometriosis Diagnosis and Treatment

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1427
Author(s):  
Karolina Iwona Kulinska ◽  
Mirosław Andrusiewicz ◽  
Anna Dera-Szymanowska ◽  
Maria Billert ◽  
Marek Skrzypski ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Stromal Cells ◽  
Integral Membrane Protein ◽  
Diagnosis And Treatment ◽  
New Strategy ◽  
17Β Estradiol ◽  
Electrochemiluminescence Immunoassay ◽  
G Protein Coupled ◽  
Estradiol Concentration ◽  
Ectopic Endometrium

Small integral membrane protein 20/phoenixin (SMIM20/PNX) and its receptor GPR173 (G Protein-Coupled Receptor 173) play a role in the regulation of the hypothalamic–pituitary–gonadal axis (HPG). The aim of the study was to determine PNX, FSH, LH, and 17β-estradiol association in women with endometriosis, and the expression of SMIM20/PNX signaling via GPR173. Serum PNX, FSH, LH, and 17β-estradiol concentrations were measured by enzyme and electrochemiluminescence immunoassay. SMIM20/PNX and GPR173 expression in the eutopic and ectopic endometrium was assessed by qPCR and immunohistochemistry. Reduced PNX level, increased LH/FSH ratio and elevated 17β-estradiol concentration were found in patients with endometriosis. No differences in SMIM20 expression were observed between the studied endometria. GPR173 expression was lower in ectopic than in eutopic endometria. SMIM20 expression was mainly restricted to stroma. GPR173 was detected in some eutopic and ectopic stromal cells and in eutopic glandular epithelial cells. Discriminant analysis indicates the diagnostic relevance of PNX and LH/FSH ratio in patients with endometriosis. In women with endometriosis, reduced PNX levels and GPR173 expression may be responsible for HPG axis dysregulation. These new insights may contribute to a better understanding of the pathophysiology of endometriosis and provide the basis for a new strategy for diagnosis and treatment of endometriosis.

scholarly journals Reproductive cycle of the Neotropical cichlid yellow peacock bass Cichla kelberi: A novel pattern of testicular development

2013 ◽  
Vol 11 (3) ◽  
pp. 587-596 ◽  
Author(s):  
Diógenes Henrique de Siqueira-Silva ◽  
Carlos Alberto Vicentini ◽  
Alexandre Ninhaus-Silveira ◽  
Rosicleire Veríssimo-Silveira
Keyword(s):  
Reproductive Cycle ◽  
Germ Cells ◽  
Light Microscope ◽  
Morphological Changes ◽  
Germinal Epithelium ◽  
Testicular Development ◽  
Preparatory Phase ◽  
Testicular Morphology ◽  
Peacock Bass ◽  
Spermatogonial Proliferation

The present study describes the testicular maturation phases (associating the germ cells development and the morphological changes suffered by the germinal epithelium along the whole year), and the testicular morphology in the yellow peacock bass Cichla kelberi, relating it to other species. For this purpose, 78 specimens were studied according conventional techniques of light microscope. The testes in C. kelberi were classified as unrestricted spermatogonial lobular, an apomorphic characteristic in the recent groups of Teleost. Furthermore, were defined five testicular maturation phases: Preparatory phase; Early Germinal Epithelium Development; Mid Germinal Epithelium Development; Late Germinal Epithelium Development and; Regression. Similar classifications were described to other species indicating that the testicular classifications based on this propose, can be applied to lots of fishes. However, besides it similarity, the testicular reproductive cycle of C. kelberifollows a different pattern in the Regression phase, on which the gonadal restructuration and the spermatogonial proliferation gathers at the same time. So, the testes in C. kelberi never return to the Preparatory phase to start a new reproductive cycle, being this one present only at the first reproductive cycle in this species. This fact also explains the absence of individuals totally spent after their first reproductive cycle.

Transdermal 17β-estradiol combined with oral progestogen increases plasma levels of insulin-like growth factor-l in postmenopausal women

1992 ◽  
Vol 15 (7) ◽  
pp. 533-538 ◽  
Author(s):  
J. Slowinska-Srzednicka ◽  
S. Zgliczynski ◽  
W. Jeske ◽  
U. Stopinska-Gluszak ◽  
M. Srzednicki ◽  
...  
Keyword(s):  
Growth Factor ◽  
Postmenopausal Women ◽  
Plasma Levels ◽  
Insulin Like Growth Factor ◽  
17Β Estradiol

Comparative plasma levels of androgens and 17β-estradiol in the diploid and triploid newt, Pleurodeles waltl

1985 ◽  
Vol 58 (3) ◽  
pp. 342-346 ◽  
Author(s):  
Christian Cayrol ◽  
Danielle Hélène Garnier ◽  
Pierre Deparis
Keyword(s):  
Plasma Levels ◽  
17Β Estradiol ◽  
Pleurodeles Waltl

LUTEINIZING HORMONE (LH) AND PROGESTERONE IN PLASMA AND LH AND OESTROGENS IN URINE DURING 42 NORMAL MENSTRUAL CYCLES

1971 ◽  
Vol 68 (3) ◽  
pp. 502-512 ◽  
Author(s):  
Elof D. B. Johansson ◽  
Leif Wide ◽  
Carl Gemzell
Keyword(s):  
Luteinizing Hormone ◽  
Urinary Excretion ◽  
Plasma Levels ◽  
Luteal Phase ◽  
Maximum Level ◽  
Plasma Progesterone ◽  
Menstrual Cycles ◽  
Normal Menstrual Cycle ◽  
The Mean ◽  
Second Peak

ABSTRACT The plasma levels of luteinizing hormone (LH) and progesterone and the urinary excretion of LH and oestrogens were measured during the normal menstrual cycle of 22 young and healthy women. A total of 42 cycles were investigated. The urinary excretion of total oestrogens increased during several days before the rise of LH in the urine. The day of maximum excretion of LH and total oestrogens coincided during the midcycle period. The mid-cyclic rise in LH was found to occur on the same day in the plasma and urine and the days of maximum values coincided in 11 out of 16 cycles. In 5 cycles the maximum level was reached one day later in the urine. The plasma levels of progesterone started to increase during the LH and oestrogen peaks. The days for maximum levels of progesterone coincided with the second peak of urinary oestrogens. The levels of progesterone in the plasma reached values above 10 ng per ml in all normal cycles. The plasma levels of progesterone were below 1 ng per ml plasma when menstrual bleeding started. The length of the luteal phase was 14.4 ± 1.1 (s) days. The sum of daily urinary excretion of total oestrogens and the sum of the daily plasma progesterone levels varied within 15 per cent of the mean in five out of six women studied during more than two cycles. The variation in values for the sums of daily oestrogen excretion and plasma progesterone levels was considerably larger between menstrual cycles of different women than between menstrual cycles of the same woman.

Active Immunization to 17β-Estradiol and Its Effects upon the Reproductive Cycle of the Rhesus Monkey

Endocrinology ◽  
1974 ◽  
Vol 94 (3) ◽  
pp. 765-776 ◽  
Author(s):  
M. FERIN ◽  
I. DYRENFURTH ◽  
S. COWCHOCK ◽  
M. WARREN ◽  
R. L. VANDE WIELE
Keyword(s):  
Rhesus Monkey ◽  
Reproductive Cycle ◽  
Active Immunization ◽  
17Β Estradiol
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