ENDOCRINE PROFILES AND FUNCTIONAL CHARACTERISTICS OF CORPORA LUTEA FOLLOWING ONSET OF POSTPARTUM OVARIAN ACTIVITY IN BEEF COWS

1983 ◽  
Vol 63 (2) ◽  
pp. 331-347 ◽  
Author(s):  
J. G. MANNS ◽  
W. D. HUMPHREY ◽  
P. F. FLOOD ◽  
R. J. MAPLETOFT ◽  
N. RAWLINGS ◽  
...  
Keyword(s):  
Light And Electron Microscopy ◽  
Beef Cows ◽  
Luteal Cell ◽  
Cell Diameter ◽  
Rapid Decline ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Functional Characteristics ◽  
Blood Samples ◽  
Endocrine Profiles

Three experiments were conducted to evaluate endocrine profiles and to determine the morphological and functional characteristics of corpora lutea (CL) following the onset of postpartum ovarian activity in beef cows, suckled by a single calf once daily. In exp. 1, blood samples were collected from 12 cows at 6-h intervals beginning 25 days postpartum until ovariectomy which was carried out on each of two cows on days 25, 27, 29, 31, 33, 35 after parturition. Ovarian structures were examined grossly and histologically. In exp. 2, blood samples were collected from eight cows at 6-h intervals for 18 days beginning 25 days postpartum and at less frequent intervals thereafter. Laparotomies were carried out on day 36 after calving, the ovaries were observed, CL were sampled and the residual tissue was marked with charcoal. A second laparotomy was performed on day 50. Luteal tissue samples were processed and examined by light and electron microscopy. Luteal cell types were evaluated, percent of area covered by large cells was determined and average luteal cell diameter was calculated. In exp. 3, seven cows were bled daily from parturition until day 25 postpartum. Serum from all experiments was assayed for progesterone (P4), FSH, LH and a prostaglandin metabolite (PGFM). The data showed that serum PGFM levels declined from a peak at calving to basal levels by 10 days postpartum which was well before the first ovulation. In all instances the observed peaks of serum LH and serum FSH preceded the first rise in P4 which, in eight of nine cases, was due to a functional CL. These CL were functional for periods of time ranging from 3 to 12 days. The regression of short-lived CL appeared abnormal compared to the longer-lived CL in which regression was characterized by a rapid decline in P4 and elevated blood PGFM. These data show clearly that the first increase in P4 is preceded by a typical LH surge, followed by ovulation and CL formation which has a variable life-span. Key words: Beef cows, postpartum, anestrus, corpus luteum.

PLASMA PROGESTERONE LEVELS IN CYCLING AND GONADOTROPHIN–PROSTAGLANDIN-TREATED HEIFERS

1976 ◽  
Vol 56 (1) ◽  
pp. 37-42 ◽  
Author(s):  
R. RAJAMAHENDRAN ◽  
P. C. LAGUË ◽  
R. D. BAKER
Keyword(s):  
Peak Level ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Dairy Heifers ◽  
The Mean

Progesterone levels were estimated by radioimmunoassay in blood samples obtained by venipuncture on the day of estrus and every alternate day until the onset of the next estrus in eight cycling dairy heifers. The mean level of progesterone was < 1 ng/ml during the first 2 days of the cycle, increased rapidly over the 4th–12th day period and reached a peak level value of 5.2 ± 1.1 ng/ml on day 14. Thereafter, the level declined rapidly to 2.6 ± 0.6 ng/ml on day 16 and then more gradually to 0.4 ± 0.1 ng/ml on day 21. In the second experiment, eight cycling heifers at diestrus were treated with gonadotrophin (2,000 IU PMSG or 1,000 IU PMSG + 1,000 IU HCG) followed 48 h later by 15 mg prostaglandin (PGF2α). Mid-ventral laparotomies were performed 4 days after the onset of estrus to observe ovarian activity. Progesterone levels were considerably higher in some animals and were slightly higher on the average after gonadotrophin treatments. The number of corpora lutea (CL) in these heifers ranged from 1 to 17. Progesterone levels of three heifers with 4–9 CL did not differ (P > 0.05) from those of three heifers with single CL. Two heifers each with 17 CL had peak progesterone levels of 38.4 and 27.8 ng/ml which were still high (9.6 and 26.5 ng/ml) by day 21. The remaining six heifers had low progesterone levels (< 1 ng/ml) by days 8–14, indicating premature regression of the CL. Thus, progesterone levels were not correlated with the number of CL.

Endocrine Profiles Associated with Life Span of Induced Corpora Lutea in Postpartum Beef Cows

1986 ◽  
Vol 62 (5) ◽  
pp. 1353-1362 ◽  
Author(s):  
M. Garcia-Winder ◽  
P. E. Lewis ◽  
D. R. Deaver ◽  
V. G. Smith ◽  
G. S. Lewis ◽  
...  
Keyword(s):  
Life Span ◽  
Beef Cows ◽  
Corpora Lutea ◽  
Endocrine Profiles

Early Embryonic Development and Ovarian Activity During Concurrent Pregnancy and Lactation in the Hopping-Mouse Notomys Alexis.

1981 ◽  
Vol 29 (4) ◽  
pp. 589 ◽  
Author(s):  
WG Breed
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Embryonic Development ◽  
Steroid Hormone ◽  
Synthetic Activity ◽  
Luteal Cell ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Pregnancy And Lactation ◽  
Further Development

In the hopping-mouse, following a postpartum mating, embryos enter the uterus on about day 5. Implantation occurs on about day 7 if there are no suckling pups, but zona-free blastocysts may remain up to day 18 if from four to seven suckling pups are present. Implantation is eccentric and initially involves interdigitation of trophectoderm and uterine epithelial cells, followed by epithelial cell displacement. The orientation is antimesometrial and, during further development, the embryo invaginates into the yolk-sac cavity. In the ovary, corpora lutea develop during the first few days of pregnancy and then remain unchanged in size or cellular morphology until implantation, regardless of the length of its delay. Peripheral progesterone levels likewise show little change during the preimplantation period. After implantation, a similar number of corpora lutea are found but they increase progressively in size due to luteal cell hypertrophy. The cells show all the organelles typical of steroid hormone synthetic activity and there is a corresponding increase in blood progesterone levels at this time. Vesicular follicles are present throughout concurrent pregnancy and lactation and are larger after implantation. There is no evidence of spontaneous ovulation except at the time of parturition.

Influence of catecholestradiol on short-lived corpora lutea in beef cows

1993 ◽  
Vol 10 (2) ◽  
pp. 95-102 ◽  
Author(s):  
M.L. Day ◽  
S.G. Kurz ◽  
K.P. Nephew ◽  
M.D. Wright ◽  
Y. Hu ◽  
...  
Keyword(s):  
Beef Cows ◽  
Corpora Lutea

scholarly journals Time- and Dose-Dependent Effects of 17 Beta-Estradiol on Short-Term, Real-Time Proliferation and Gene Expression in Porcine Granulosa Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Sylwia Ciesiółka ◽  
Joanna Budna ◽  
Karol Jopek ◽  
Artur Bryja ◽  
Wiesława Kranc ◽  
...  
Keyword(s):  
Real Time ◽  
Granulosa Cells ◽  
Hormone Receptor ◽  
Proliferative Activity ◽  
Cell Transformation ◽  
Luteinizing Hormone Receptor ◽  
Luteal Cell ◽  
Ovarian Activity ◽  
Short Term

The key mechanisms responsible for achievement of full reproductive and developmental capability in mammals are the differentiation and transformation of granulosa cells (GCs) during folliculogenesis, oogenesis, and oocyte maturation. Although the role of 17 beta-estradiol (E2) in ovarian activity is widely known, its effect on proliferative capacity, gap junction connection (GJC) formation, and GCs-luteal cells transformation requires further research. Therefore, the goal of this study was to assess the real-time proliferative activity of porcine GCs in vitro in relation to connexin (Cx), luteinizing hormone receptor (LHR), follicle stimulating hormone receptor (FSHR), and aromatase (CYP19A1) expression during short-term (168 h) primary culture. The cultured GCs were exposed to acute (at 96 h of culture) and/or prolonged (between 0 and 168 h of culture) administration of 1.8 and 3.6 μM E2. The relative abundance of Cx36, Cx37, Cx40, Cx43, LHR, FSHR, and CYP19A1 mRNA was measured. We conclude that the proliferation capability of GCs in vitro is substantially associated with expression of Cxs, LHR, FSHR, and CYP19A1. Furthermore, the GC-luteal cell transformation in vitro may be significantly accompanied by the proliferative activity of GCs in pigs.

scholarly journals Metabolic Attributes, Milk Production and Ovarian Activity of Ewes Supplemented with a Soluble Sugar or a Protected-Fat as Different Energy Sources During Postpartum Period

2017 ◽  
Vol 17 (1) ◽  
pp. 229-240 ◽  
Author(s):  
Nesrein M. Hashem ◽  
Samir Z. El-Zarkouny
Keyword(s):  
Milk Production ◽  
Postpartum Period ◽  
Serum Insulin ◽  
Soluble Sugar ◽  
Body Weight Loss ◽  
Experimental Period ◽  
Energy Sources ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Serum Triglycerides

Abstract The effects of two dietary supplemental energy sources on metabolic attributes, milk production and ovarian activity of ewes during early to mid-postpartum period were studied using thirty multiparous lactating ewes (Rahmani × Barki) weighing 43.10±1.22 kg and 3-6 years old. The ewes were assigned to three groups (n=10 per group). All ewes received the same diet supplemented with isocaloric and isonitrogenous protected-palm oil (50 g/ewe/d, F-group) or a sugar cane molasses (140 g/ewe/d, M-group) or without supplementation (control, C-group), for 60 days starting 2 weeks postpartum. Results showed that, during the experimental period, both energy sources reduced (P<0.05) body weight loss of ewes compared with the control (2.57 kg in F-group, 0.911 kg in M-group and 4.71 kg in C-group). The metabolic profiles of ewes were affected by the sources of energy, the highest (P<0.05) concentration of serum triglycerides was in the F-group, whereas the highest (P<0.05) concentration of serum insulin was in the M-group. The lowest serum glucose concentration was (P<0.05) in the F-group (73.20 mg/dL) and the highest in the C-group (76.85 mg/dL), whereas it was intermediate in the M-group (74.69 mg/dL). Ewes in the F-group had (P<0.05) the highest milk yield and energy-corrected milk (531.72 g/d and 554.40 g/d, respectively) compared with those in the M-group (491.76 g/d and 525.12 g/d, respectively) and C-group (429.96 g/d and 462.00 g/d, respectively). The highest (P<0.05) number of corpora lutea (CL; ovulation activity) was in the F-group (0.45), whereas it was not different between the M-group (0.25) and the C-group (0.15). In conclusion, during early to mid-postpartum period, protected-fat supplementation increased serum triglycerides concentration which was effectively used as an energyyielding nutrient for improving milk production. It could also be suggested that specific fatty acid in protected-fat improved quality of the ovulatory follicle and thus occurrence of ovulation.

COMPARISON OF ARTIFICIAL INSEMINATION AND NATURAL MATING ON REPRODUCTIVE PERFORMANCE OF FIVE STRAINS OF SHEEP DURING THE ANESTROUS SEASON IN AN INTENSIVE SYSTEM

1979 ◽  
Vol 59 (4) ◽  
pp. 675-683 ◽  
Author(s):  
A. J. HACKETT ◽  
H. A. ROBERTSON ◽  
E. K. INSKEEP ◽  
J. N. B. SHRESTHA ◽  
M. S. WOLYNETZ
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Hormone Treatment ◽  
Corpora Lutea ◽  
Blood Samples ◽  
Natural Mating ◽  
Main Effects ◽  
Mating Method ◽  
Intensive System

Synchronized estrus and ovulation were induced during the anestrous season (April–May 1974) in 373 ewes of three synthetic (one sire and two dam) strains and two unselected (Suffolk and Finnish Landrace) purebred strains by treatment with 30 mg fluorogestone acetate (FGA) impregnated in polyurethane intravaginal sponges for 12 days. Following sponge removal each ewe received 500 IU pregnant mares’ serum gonadotrophin (PMSG) IM. Of these, 167 were bred by artificial insemination (AI) at 48 and 60 h post sponge removal with 0.2 ml raw unextended semen collected by electroejaculation (EE). Five days after AI, ewes were exposed to a follow up ram for 16 days for subsequent mating if a second estrus occurred. The remaining 206 were exposed to rams for a period of 22 days for natural mating. Blood samples were collected from 69 ewes, 9, 19 and 27 days post sponge removal and analyzed for progesterone to ascertain if corpora lutea were formed and whether the ewes recycled. The age of ram by mating method interaction significantly affected both fertility and fecundity mainly because some of the younger rams lacked libido and experience for natural mating. There were no significant differences in prolificacy due to any of the main effects tested. Among the 69 ewes examined for progesterone levels, 93% had formed corpora lutea after hormone treatment and 16% recycled. Only 16 of the 255 ewes that did not conceive to the synchronized estrus lambed to the subsequent estrus.

Seasonal differences in ovarian activity in cows

1984 ◽  
Vol 102 (2) ◽  
pp. 189-198 ◽  
Author(s):  
K. P. McNatty ◽  
N. Hudson ◽  
M. Gibb ◽  
K. M. Henderson ◽  
S. Lun ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Ovarian Function ◽  
Plasma Concentrations ◽  
Peak Frequency ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Aromatase Activity ◽  
Plasma Prolactin ◽  
Seasonal Differences ◽  
Time Of Year

ABSTRACT The plasma concentrations of LH and prolactin and various parameters of ovarian function were examined in cows on known days of the oestrous cycle during May and June (autumn and winter) and during October (spring). Luteinizing hormone peak frequency and plasma prolactin concentrations were significantly higher in October than during the May–June period (LH, P<0·05; prolactin, P<0·01). The mean diameters of large healthy follicles (≥8 mm diameter) and the dominant oestrogen-secreting follicles were significantly larger (P<0·01 for both follicle types) and each follicle contained more granulosa cells (both P<0·01) in May–June than in October. The LH responsiveness of theca interna with respect to androstenedione production and the levels of aromatase activity in granulosa cells did not differ with time of year. The corpora lutea were heavier (P<0·05) and secreted more progesterone (P<0·01) in May–June than in October. It is concluded that seasonal differences in ovarian activity exist in cows and that these differences are probably the consequence of seasonal differences in gonadotrophin secretion. J. Endocr. (1984) 102, 189–198

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