Studies on the Ovaries of the Humback Whale, Megaptera nodosa (Bonnaterre), on the Western Australian Coast

1954 ◽  
Vol 5 (1) ◽  
pp. 35 ◽  
Author(s):  
RG Chittleborough

Observations on the increase of ovarian weight in the female humpback whale cover stages from late foetal life until after the attainment of sexual maturity. Variations in ovary weight during different phases of the reproductive cycle are recorded. Graafian follicles up to 0.13 mm in diameter have been found in the foetal ovary just prior to birth. These initially develop until from 11 to 29 mm (median value 20 mm) in diameter when the female reaches the maturing length range. At sexual maturity one of these follicles enlarges, exceeding 30 mm in diameter before rupture. After ovulation a corpus luteum is rapidly formed and if conception has taken place, this gland enlarges and remains active until parturition. After parturition there is rapid resorption of the corpus luteum to form a corpus albicans. Variations in the sizes and weights of functional corpora lutea are discussed. There is considerable reduction in the diameters of Graafian follicles in late pregnancy to a median value of 6 mm. After parturition follicles enlarge so that in the ovaries of females in late lactation the largest follicles once more range from 11 to 29 mm in diameter with a median value of 20 mm. In an ovulatory period of from June to November the maximum frequency of ovulations is in late July, though considerable numbers occur in August and September. On the availabIe evidence most female humpback whales ovulate only once in their ovulatory period, a few ovulate twice, and extremely few three times.

2002 ◽  
Vol 75 (3) ◽  
pp. 427-432 ◽  
Author(s):  
Ş. Arikan ◽  
A. A. Yigit

AbstractThe present study examines the size distribution of ovine steroidogenic and non-steroidogenic luteal cells throughout pregnancy. Cells were isolated from corpora lutea collected from early (< 8 weeks), mid (9 to 14 weeks) or late (15 to 18 weeks) stages of pregnancy. Cells were stained for 3β-hydroxysteroid dehydrogenase (3β-HSD) activity, a marker for steroidogenic cells. Both 3β-HSD positive and β-HSD negative cells covered a wide spectrum of size ranging from 7 to 37 μm in diameter. There was a significant increase (P > 0·01) in mean diameter of non-steroidogenic luteal cells as pregnancy progressed. Mean diameter of 3β-HSD negative cells increased from 17·8 (s.e. 0·4) μm in the corpus luteum of early stage of pregnancy to 22·4 (s.e. 0·3) μm in the corpus luteum of advanced pregnancy. However, there was no significant increase in the mean diameter of 3β-HSD positive cells. Corpora lutea obtained from early stages of the pregnancy contained more steroidogenic cells than the cells obtained from mid and late pregnancy (P < 0·01). Percentage of 3β-HSD negative cells had increased 2·07-fold by 18 weeks of pregnancy when compared with the early stage of pregnancy. In contrast, percentage of 3β-HSD positive cells had decreased to 50% of starting values during the same period (P < 0·05). These results indicate that the ovine corpus luteum of pregnancy is morphologically dynamic over the course of pregnancy. Steroidogenic activity of luteal cells may decrease as pregnancy progresses, especially activity of the large luteal cells.


1955 ◽  
Vol 6 (3) ◽  
pp. 315 ◽  
Author(s):  
RG Chittleborough

At puberty the mean body length of the female humpback whales on the Western Australian coast is 38.60 � 0.18 ft. It is demonstrated that this length gives a reliable means of calculating the proportion of sexually immature females in a series where the lengths are known. Sexual maturity (based upon the first pregnancy) may either follow immediately upon puberty or be delayed for a further year. At the approach of physical maturity (when epiphysial fusion begins) the mean body length is 45.08 � 0.29 ft. At this stage an average of 19 ovulations have occurred. On the available material, physical maturity is reached at a mean length of 44.34 � 0.72 ft, when close to 30 ovulations have occurred. Growth in body length of sexually mature females becomes very slow even before epiphysial fusion begins. The significance of the high number of ovulations before the attainment of physical maturity is discussed. The proportion of physically mature individuals amongst the females in recent catches off the Western Australian coast is extremely low (1.8 per cent. of 457 females examined). The lengths of male and female humpback whales at puberty, at the approach of physical maturity, and at physical maturity are compared.


1972 ◽  
Vol 54 (1) ◽  
pp. 79-85 ◽  
Author(s):  
H. B. WAYNFORTH ◽  
D. M. ROBERTSON

SUMMARY Oestradiol-17β in ovarian venous blood and ovarian tissue was assayed by a competitive protein-binding method. Oestradiol was found in similar amounts in the ovarian vein blood of pregnant rats hypophysectomized on Day 12 and killed on Days 16 and 21 and in pregnant rats sham-hypophysectomized on Day 12 and killed on Day 16. The pituitary therefore plays no part in oestrogen production after mid-pregnancy until some time between Day 16 and Day 21, when it gives rise to an increased ovarian venous blood oestradiol content just before parturition, in intact sham-hypophysectomized rats. It is suggested that this increase is associated with the advent of the post-partum ovulation. The corpus luteum and the extraluteal component of the ovary in hypophysectomized rats autopsied on Days 16 and 21 and in sham-hypophysectomized rats autopsied on Day 16, contain similar amounts of oestradiol within each group. The extraluteal component contains about five times more oestradiol than corpora lutea in sham-hypophysectomized intact rats autopsied on Day 21. The ovaries of these animals also show an increased amount of oestradiol over that of the ovaries in the other three groups. It is suggested that secretion of oestradiol after mid-pregnancy in rats involves concurrently both the corpus luteum and the extraluteal component of the ovary.


1975 ◽  
Vol 80 (1) ◽  
pp. 149-164 ◽  
Author(s):  
M. Axelson ◽  
G. Schumacher ◽  
J. Sjövall ◽  
B. Gustafsson ◽  
J. O. Lindell

ABSTRACT Neutral steroids in bovine corpus luteum were isolated by liquid-gel chromatography on hydrophobic Sephadex, and were analyzed by computerized gas chromatography-mass spectrometry. The presence of progesterone and 20β-hydroxy-4-pregnen-3-one was confirmed. In addition, 3β- hydroxy- 5- pregnen -20- one, 5- pregnene- 3β,20β -diol, 3β-hydroxy-5α-pregnan-20-one and 5α-pregnane-3β,20β-diol,32 were fully identified, and 3-hydroxy-4-pregnen-20-onne, 4 pregnene-3,20-diol, 22-hydroxycholesterol and 20,22-dihydroxycholesterol were partially characterized. Steroid sulphates were not detected. Quantification of the six fully identified steroids was based on peak areas in specific fragment ion current chromatograms constructed by the computer. During the 4th–19th day of the oestrous cycle the steroid concentrations varied as follows: progesterone 6.0–36.7 μg/g wet luteal weight, 20β-hydroxy-4-pregnen-3-one 0.8–5.5 μg/g, 3β-hydroxy-5-pregnen-20-one 1.0–7.1 μg/g, 5-pregnene-3β,20β-diol < 0.2–0.9 μg/g, 3β-hydroxy-5α-pregnan-20-one 1.7–8.6 μg/g, and 5α-pregnane-3β,20β-diol < 0.2-1.2 μg/g. The concentrations of progesterone and 3β-hydroxy-5-pregnen-20-one seemed to vary in parallel and were low during days 11–17. During this period the concentrations of 5-pregnene-3β,20β-diol and 5α-pregnane-3β,20β-diol were highest as was the relative contribution of all three 20β-hydroxysteroids to the total amount of steroids. The relative amount of 3β-hydroxy-5α-pregnan-20-one seemed to be highest during days 4–6. The total steroid concentration in corpora lutea taken in early pregnancy (75–105 days) was 18–47 μg/g. In the period 75–90 days, progesterone constituted only 35–42 % of the total steroids, 3β-hydroxy-5α-pregnan-20-one as much as 23–40 % and the total 20β-hydroxysteroids 18–30%. The total steroid concentration in corpora lutea taken in midterm and late pregnancy was 21–77 μg/g. In this period progesterone was by far the predominant steroid and constituted about 80–90 % of the total steroids in corpora lutea taken between days 150 and 240. Possible correlations between luteal growth, steroid oxidoreductases and steroid concentrations are discussed.


2005 ◽  
Vol 33 (06) ◽  
pp. 395-403 ◽  
Author(s):  
M. Thumes ◽  
M. Holsteg ◽  
K. Failing ◽  
H. Bostedt ◽  
R. Hospes

Zusammenfassung Ziel der Untersuchung: Überprüfung der Wirksamkeit von DL-Cloprostenol vs. D-Cloprostenol in der Östrusinduktion bei Milchrindern. Probanden und Methoden: Das Probandenkollektiv umfasste 134 Rinder im Durchschnittsalter von 4,0 ± 0,5 Jahren (99 in Laktation, 35 Färsen). Vor alternierender Injektion zweier Cloprostenolpräparate (Gruppe A: DL-Cloprostenol, 500 μg, n = 70; Gruppe B: D-Cloprostenol, 150 μg, n = 64) wurde die Progesteronkonzentration im Serum bestimmt. Gynäkologische Kontrollen erfolgten 0–3 d post injectionem (p. inj.), wobei die als inseminationsfähig beurteilten Probanden (n = 123) am dritten Tag besamt wurden. Ergebnisse: In beiden Gruppen kam es bis zum dritten Tag p. inj. zu einer deutlichen Konsistenzänderung oder Regression der Corpora lutea (p ≤ 0,001). Die Lysis eines C. l. periodicum verlief bei Kühen markanter als bei Färsen (p ≤ 0,017). Insgesamt war D-Cloprostenol dem DL-Cloprostenol hier leicht überlegen. Am dritten Tag p. inj. wiesen 67,1% (A) bzw. 71,9% (B) der Probanden gut ausgeprägte Östrusanzeichen auf. Als inseminationsfähig wurden 94,3% (A) und 89,1% (B) der Tiere eingestuft. Ein geringer Präparateunterschied bestand hinsichtlich des Graviditätsresultates. Bei einem C. l. persistens verlief die Regression weniger progressiv als bei einem C. l. periodicum (p ≤ 0,024). Signifikante Wechselwirkungen zwischen den Einflussfaktoren Präparat und Indikation einerseits sowie für die übrigen gynäkologischen Kriterien andererseits ergaben sich nicht. Bei den Probanden mit prostaglandininduziertem Zyklus nach einem C. l. persistens lag die Graviditätsrate nach der 1. KB deutlich niedriger (31,9%) als bei Tieren nach Lysis eines C. l. periodicum (52,4%, p = 0,08). Schlussfolgerungen und klinische Relevanz: Der Einsatz von D-Cloprostenol erbringt im Wesentlichen die Resultate wie der von DL-Cloprostenol. Eine Überlegenheit konnte jedoch für die Progressivität der lytischen Wirkung des D-Cloprostenols festgestellt werden. Kühe mit C. l. persistens reagierten präparateunabhängig weniger intensiv als solche mit C. l. periodicum.


1964 ◽  
Vol 45 (1) ◽  
pp. 1-12 ◽  
Author(s):  
H. E. Swanson ◽  
J. J. van der Werff ten Bosch

ABSTRACT The »early-androgen« syndrome in the rat – i. e. anovulatory ovaries in adult females after a single injection of testosterone propionate (TP) within a week of birth – may not become apparent until some time after the attainment of sexual maturity. Large doses (50 or 100 μg) of TP were effective earlier than lower doses (5 or 10 μg). Rats which received 5 μg TP were ovulating at 10 weeks of age, mated but were infertile at 13 weeks of age, and were anovulatory at 21 weeks. In rats between 10 and 13 weeks old there was a marked fall in the number of corpora lutea in the ovaries of animals which had been given 5 μg TP. Hemi-spaying was followed by compensatory growth of the remaining ovary which consisted of corpora lutea in ovulating, and of follicles in anovulatory rats; little or no compensatory weight increase occurred in animals which seemed to be in the transition stage from the ovulatory to the anovulatory condition.


1968 ◽  
Vol 59 (2_Suppl) ◽  
pp. S35-S51 ◽  
Author(s):  
B. L. Lobel ◽  
E. Levy

ABSTRACT Activities of various hydrolases and dehydrogenases were studied during the formation, development and involution of cyclic corpora lutea and in the corpora lutea of early pregnancy. At 24 hours postovulation the luteal cells, whether of granulosal or thecal origin, contained demonstrable levels of Δ5-3β-hydroxysteroid dehydrogenase and the NADP and NADPH2 diaphorases. During the period of proliferation and cellular growth, enzymic activities in the luteal cells were moderate at first, and then increased. In the mature corpus luteum, activities of the dehydrogenases occurred in all luteal cells but were most intense in the large polymorphic luteal cells. Activities of hydrolytic enzymes, low in the immediate postovulatory period, increased with the development of the vascular system. Enzymic characteristics of corpora lutea of gestation were similar to those of cyclic corpora, except for phosphorylase activity which was observed in luteal cells in gestational corpora, but confined to the vascular walls in cyclic corpora. No increase in activities of 17β- and 20β-hydroxysteroid dehydrogenases (above those seen in pre-ovulatory follicles) were observed after incubation of sections of either mature cyclic or gestational corpora. Involution of cyclic corpora lutea began with degenerative changes in the blood vessels: pyknosis of the endothelial cell nuclei and a sudden decline in activities of hydrolytic enzymes in the vascular walls. Subsequently, the luteal cells showed a sharp decrease in activities of the dehydrogenases as well as other signs of regressive change. The cytochemical findings are discussed in relation to biochemical observations on steroid synthesis by the bovine corpus luteum.


1986 ◽  
Vol 113 (4) ◽  
pp. 570-575 ◽  
Author(s):  
Firyal S. Khan-Dawood

Abstract. Immunoreactive oxytocin is detectable in the corpora lutea of women and cynomolgus monkeys by radioimmunoassay. To localize the presence of oxytocin and neurophysin I in ovarian tissues of subhuman primates, three corpora lutea and ovarian stromal tissues and two Fallopian tubes obtained during the menstrual cycle of the baboon and decidua from two pregnant baboons were examined using highly specific antisera against either oxytocin or neurophysin I and preoxidase-antiperoxidase light microscopy immunohistochemistry. Oxytocin-like as well as neurophysin I-like immunoreactivities were found in some cells of all the corpora lutea only, but could not be demonstrated in ovarian stromal tissues, Fallopian tubes and decidua. Specificity of the immunocytochemical reaction was further confirmed by immunoabsorption of the antiserum with excess oxytocin or neurophysin, after which the immunoreactivities for both oxytocin and neurophysin in the luteal tissue were negative. Similar controls using normal rabbit serum gave no positive staining for either oxytocin or neurophysin. Counterstaining of the positive immunoreactivities for oxytocin and neurophysin I with Mayer's haematoxylin and eosin demonstrated clearly that the oxytocin and neurophysin I appeared as granular material mainly within the cytoplasm of the luteal cells. The localization of immunoreactive oxytocin and neurophysin I in the corpus luteum of the baboon demonstrates directly the presence of these two neurohypophysial peptides within primate luteal cells and suggests their local production.


1991 ◽  
Vol 19 (01) ◽  
pp. 61-64 ◽  
Author(s):  
Satoshi Usuki

The effect of herbal components of Tokishakuyakusan on somatomedin C/insulin-like growth factor I (IGF-1) level in medium from rat corpora lutea incubated in vitro was examined. Hoelen + peony root + Japanese angelica root, hoelen + peony root, hoelen + Japanese angelica root or peony root + Japanese angelica root decreased the IGF-1 level. The data suggest that constituent herbal components of Tokishakuyakusan regulate the IGF-1 level by rat corpora lutea.


1987 ◽  
Vol 112 (2) ◽  
pp. 317-322 ◽  
Author(s):  
J. E. Sánchez-Criado ◽  
K. Ochiai ◽  
I. Rothchild

ABSTRACT Adult female rats were hypophysectomized and their pituitary glands autotransplanted beneath the left kidney capsule on day 2 (day 1 was the day of ovulation). In such rats the pituitary secretes prolactin fairly constantly and the corpora lutea secrete progesterone for several months. To induce the luteolytic effect of prolactin the rats were first injected s.c. with 2-bromo-α-ergocryptine (CB-154) on cycle days 12, 13 and 14 (i.e. 10, 11 and 12 days after operation) to depress prolactin secretion, and then with CB-154 vehicle (70% ethanol) daily until cycle day 21, to allow prolactin secretion to resume. One ovary was removed from each rat on day 15 and the remaining one on day 22. The mean (± s.e.m.) weight of the corpora lutea on day 15 was 1·46±0·06 mg and 0·98±0·07 mg on day 22 (n = 17). In contrast, rats in which the CB-154 treatment was maintained to day 21 had corpora lutea which weighed 1·31 ±0·09 on day 15 and 1·47 ±0·08 mg on day 22 (n = 15). To investigate whether indomethacin, a prostaglandin synthesis inhibitor, affected the luteolytic action of prolactin, the experiment was repeated, but on day 15 (after the removal of one ovary) the groups in which CB-154 treatment was stopped, as well as the group in which CB-154 treatment was maintained, were each divided into two groups. In one, indomethacin-containing silicone elastomer wafers and, in the other, blank silicone elastomer wafers, were placed within the bursa of the remaining ovary. There were no differences in corpus luteum weight on day 15 among any of these groups and the two groups of the first experiment. There was no significant difference in corpus luteum weight between day 15 and day 22 in any of the six groups except for the two groups treated with the CB-154 vehicle and not with indomethacin. Thus, treatment with indomethacin prevented the fall in corpus luteum weight associated with the discontinuation of CB-154 treatment. Serum prolactin levels fell until day 15 in all rats and remained low in those in which the CB-154 treatment was maintained to day 21, but returned to control values in those treated with vehicle after day 14. Serum progesterone levels fell and remained low in all groups. Indomethacin treatment had no effect on the levels of either serum prolactin or progesterone. We conclude that some of the pharmacological effects of indomethacin are to prevent prolactin-induced luteolysis, and we suggest that prolactin induces rapid regression of the corpus luteum by stimulating intraluteal prostaglandin production or by being necessary for the effect of luteolytic prostaglandins. J. Endocr. (1987) 112, 317–322


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