Progesterone as the driving regulatory force behind serum FSH concentrations and antral follicular development in cycling ewes

2011 ◽  
Vol 23 (2) ◽  
pp. 303 ◽  
Author(s):  
Tanya E. Baby ◽  
Pawel M. Bartlewski
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Treated Group ◽  
Time Frame ◽  
Oestrous Cycle ◽  
Control Group ◽  
Corpora Lutea ◽  
Follicular Waves ◽  
Follicular Wave ◽  
And Control

Ovarian antral follicles in sheep grow in an orderly succession, producing typically three to four follicular waves per 17-day oestrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe’s oestrous cycle, the time between the first two FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged interpeak and interwave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or not fully functional, corpora lutea (CL). The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe, i.m.) was administered twice daily to six cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the interwave interval); six animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0–9). Jugular blood samples were drawn twice a day from Day 0 to Day 4 and then daily until Day 9 to measure systemic concentrations of P4, FSH and 17β-oestradiol (E2). The first FSH peak after ovulation was detected on Days 1.5 ± 0.2 and 4.2 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Day 3.9 ± 0.3 in the treated group and on Day 6.4 ± 0.5 in the control group. Consequently, the treated group had, on average, three follicular waves emerging on Days 0, 3 and 6, whereas the control group had two waves emerging on Days 0 and 5. Mean serum E2 concentrations were greater (P < 0.05) in control compared with treated ewes on Days 1.3, 2.3, 3.3, 4.0 and 4.3 after ovulation. In summary, creation of mid-luteal phase levels of P4 in metoestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in the emergence of one more follicular wave compared with control ewes during the same time frame. Therefore, P4 appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cycling sheep.

1 PROGESTERONE AS THE DRIVING REGULATORY FORCE BEHIND SERUM FSH CONCENTRATIONS AND ANTRAL FOLLICULAR GROWTH IN CYCLIC EWES

2010 ◽  
Vol 22 (1) ◽  
pp. 159
Author(s):  
T. E. Baby ◽  
P. M. Bartlewski
Keyword(s):  
Treatment Group ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Follicular Development ◽  
Serum Levels ◽  
Time Frame ◽  
Corpora Lutea ◽  
Research Station ◽  
Follicular Growth ◽  
Follicular Waves

Ovarian antral follicles in sheep grow in an orderly succession, producing typically 3 to 4 follicular waves per 17-day estrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe's estrous cycle, the time between the first 2 FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged inter-peak/inter-wave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or non-fully functional, corpora lutea. The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe i.m.) was administered twice daily to 6 cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the inter-wave interval); 6 animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0 to 9). Jugular blood samples were drawn twice a day from Day 0 to 4 and then daily until Day 9 to measure systemic concentrations of P4 and FSH. The first FSH peak post-ovulation was detected on Day 1.4 ± 0.2 and 4.0 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Days 3.4 ± 0.3 and 5.2 ± 0.2 in the treatment group and on Day 5.5 ± 0.3 in controls. Consequently, the treatment group had, on average, 3 follicular waves emerging on Days 0, 3, and 6, whereas the controls produced 2 waves emerging on Days 0 and 5 (P < 0.05).We then retrospectively analyzed and compared daily serum concentrations of P4 and FSH obtained in cyclic Western White Face ewes (Columbia × Rambouillet) that had 3 (n = 10) or 4 (n = 19) follicular waves per cycle. Mean P4 concentrations were greater (P < 0.05) in sheep with 4 waves per cycle compared with their counterparts, which had 3 waves of follicular growth. Interestingly, the ewes with 3 waves exceeded (P < 0.05) all animals with 4 follicular waves in mean serum FSH concentrations on Days 0 to 2, 6 to 7, and 9 to 15 post-ovulation. In summary, creation of mid-luteal phase levels of P4 in metestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in emergence of one more follicular wave compared with control animals during the same time frame. The ewes exhibiting 4 waves of follicular emergence had greater serum levels of P4 but lower FSH concentrations compared with sheep with 3 waves per cycle. Therefore, progesterone appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cyclic sheep. This study was funded by OMAFRA and NSERC grants. Appreciation is extended to Norman C. Rawlings, Susan Cook, and Sekallu Srinivas (University of Saskatchewan) and the staff at Ponsonby Sheep Research Station.

388 SUPEROVULATION TREATMENT BY A SINGLE INJECTION OF FSH WITH ALUMINUM HYDROXIDE GEL IN HOLSTEIN CATTLE

2007 ◽  
Vol 19 (1) ◽  
pp. 309
Author(s):  
S. Matoba ◽  
M. Tagawa ◽  
H. Matsuda ◽  
H. Yoshioka ◽  
K. Kimura ◽  
...  
Keyword(s):  
Aluminum Hydroxide ◽  
Single Injection ◽  
Follicular Development ◽  
Advanced Technology ◽  
Inguinal Region ◽  
Control Group ◽  
Corpora Lutea ◽  
Holstein Cattle ◽  
Embryo Recovery ◽  
And Control

The objective of this study was to examine the effect of administration of FSH in aluminum hydroxide gel (Gel; an adjuvant and adsorbent of large molecules) by a single injection on superovulatory response and embryo recovery in cattle. In this study, cloprostenol-synchronized (PGF; Clopromate C; Sumitomo Pharmaceuticals Co., Tokyo, Japan) nonlactating Holstein cows were divided into 2 groups (Gel-treated and Controls) between Days 8 and 11 after estrus in 2 experiments in a crossover design. In Experiment 1, 40 mg FSH (Antrin-R10; Kawasaki Mitaka Pharmaceutical Co., Tokyo, Japan) was mixed with 10 mL aluminum hydroxide suspended in saline at a concentration of 3 mg Al mL-1 and administered by a single IM injection (n = 12; 10 mL-Gel group). Blood samples were collected at 0, 1, 2, 4, 8, and 12 h, and thereafter every 24 h until embryo recovery for measurement of FSH levels in a time-resolved fluoroimmunoassay. In Experiment 2, 40 mg FSH was mixed with 5 mL Gel and injected into fat in the inguinal region (n = 8, 5 mL-Gel group). The Control group in both experiments (n = 2 and n = 8, respectively) received 40 mg FSH twice daily for 4 days in decreasing doses (8, 8, 6, 6, 4, 4, 2, and 2 mg) by IM injection (Experiment 1), or in the inguinal region (Experiment 2). PGF (0.75 mg) was administered twice on the third day of treatment, and cows were inseminated 48 and 60 h after second PGF dose; embryo recovery was performed 7 days later. Follicular development was monitored ultrasonically every 24 h from the first FSH treatment to ovulation, and the numbers of medium (MF, 5–8 mm) and large (LF, &gt;8 mm) follicles, and corpora lutea (CL) were counted on the day of embryo recovery. Data were analyzed by Student&apos;s t-test. In Experiment 1, there were no differences in the mean (� SD) number of CL or transferable embryos between the 10 mL-Gel (10.5 � 9.6 and 6.0 � 8.0, respectively) and Control (14.8 � 9.6 and 9.0 � 6.6, respectively) groups (P &gt; 0.1). The growth of LF and MF in the 10 mL-Gel group occurred 24 h earlier than in the Control group (24 and 48 h after initiation of FSH treatment, respectively; P &lt; 0.05). However, follicle growth stopped at 72 h in the 10 mL-Gel group and at 96 h in the Control group (P &lt; 0.01). FSH concentrations in the 10 mL-Gel group increased markedly to 2.0 � 0.7 ng mL-1 at 12 h, remained there at 24 h, and decreased to 1.0 � 0.3 ng mL-1 at 72 h, whereas FSH concentrations in the Control group increased gradually to 1.1 � 0.3 ng mL-1 at 24 h, remained at 1.2 � 0.3 ng mL-1 from 24 to 96 h, and then decreased to baseline (0.9 � 0.3 ng mL-1) at 120 h (P &lt; 0.05). In Experiment 2, no significant differences in number of CL or transferable embryos were found between the 5 mL-Gel (11.8 � 13.0 and 4.1 � 4.0, respectively) and Control (12.0 � 11.0 and 4.0 � 3.1, respectively) groups, and follicular growth profiles did not differ between groups (P &gt; 0.4). Results suggest that administration of FSH in 5 mL Gel by a single injection in the inguinal region is effective in inducing superstimulation in Holstein cattle. This work was supported by a grant of the Research Project for Utilizing Advanced Technology (04-1676).

scholarly journals Role of low circulating FSH concentrations in controlling the interval to emergence of the subsequent follicular wave in cattle

Reproduction ◽  
2002 ◽  
pp. 475-482 ◽  
Author(s):  
OJ Ginther ◽  
DR Bergfelt ◽  
MA Beg ◽  
K Kot
Keyword(s):  
Dosage Regimen ◽  
Treated Group ◽  
Systemic Effect ◽  
Reciprocal Relationship ◽  
Control Group ◽  
Follicular Waves ◽  
Follicular Wave ◽  
Follicle Diameter ◽  
Stimulation Of

The intervals between emergence of follicular waves 1 (first wave of an oestrous cycle) and 2, and between the associated FSH surges (surges 1 and 2), were studied in control (n = 7) and recombinant bovine (rb)FSH-treated (n = 7) heifers. The expected start of the deviation in follicle diameter between the two largest follicles of wave 1 was defined as the day on which the largest follicle reached 8.5 mm (day 0). In the control heifers, circulating concentrations of FSH decreased and oestradiol increased between day 0 and day 1.5 or day 2.0 in a reciprocal relationship. The opposite reciprocal relationship between an FSH increase and an oestradiol decrease occurred during the next 3 days. This temporal result is consistent with a negative systemic effect of oestradiol on FSH at this time. rbFSH was administered in a dosage regimen that was expected to result in a similarity between FSH surge 2 in the rbFSH-treated group and surge 2 in the control group. On average, surge 2 and wave 2 occurred approximately 2 days earlier in the rbFSH-treated group than in the control group, and characteristics of the FSH surge and follicular wave were similar (no significant differences) between groups. These results support the hypothesis that low circulating FSH concentrations after the deviation in follicle diameter control the interval to emergence of the subsequent follicular wave. However, in one of seven rbFSH-treated heifers, the largest follicle from the apparent stimulation of rbFSH reached only 5.7 mm; therefore, the possibility of involvement of additional mechanisms cannot be dismissed.

Effects of melatonin treatment on follicular development and oocyte quality in Chios ewes — Short communication

2009 ◽  
Vol 57 (2) ◽  
pp. 331-335 ◽  
Author(s):  
Theodora Tsiligianni ◽  
Irene Valasi ◽  
Sándor Cseh ◽  
Emmanuel Vainas ◽  
Vera Faigl ◽  
...  
Keyword(s):  
Follicular Development ◽  
Treated Group ◽  
Oocyte Quality ◽  
Control Group ◽  
Melatonin Treatment ◽  
Oocyte Competence ◽  
Follicular Aspiration ◽  
Laparoscopic Evaluation ◽  
And Control

Follicular development and oocyte quality were assessed by laparoscopic observation and in vitro fertilisation, respectively, in melatonin-treated (Group M) and control (Group C) anoestrous Chios ewes (n = 10 in each group). Fourteen days after melatonin insertion, all ewes had laparoscopic evaluation of the follicular population followed by oocyte pick-up (OPU); on day 22 intravaginal progestagen sponges were inserted for 14 days. Two days after sponge removal the follicular population was re-evaluated and a second follicular aspiration was performed. Collected oocytes from the second OPU underwent in vitro maturation, fertilisation and culture. The number of large follicles was higher in Group M than in the control ewes during the first OPU and tended to be so (P = 0.06) at the second. Morphologically, oocytes collected from controls were of better quality than those from Group M; however, more oocytes collected from melatonintreated animals fertilised and developed in vitro . These results indicate that melatonin is a potent regulator of follicular development and oocyte competence during the anoestrous period of the ewe.

Ovulation rate, follicle population and FSH levels in cyclic rats after administration of an inhibin-neutralizing antiserum

1991 ◽  
Vol 130 (2) ◽  
pp. 297-303 ◽  
Author(s):  
H. J. Sander ◽  
P. Kramer ◽  
E. C. M. van Leeuwen ◽  
W. A. van Cappellen ◽  
H. M. A. Meijs-Roelofs ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Treated Group ◽  
Immune Serum ◽  
Ovulation Rate ◽  
Control Group ◽  
Corpora Lutea ◽  
Follicle Growth ◽  
Control Data ◽  
Single Intraperitoneal Injection ◽  
And Control

ABSTRACT Ovulation rate, follicle growth, serum FSH and oestradiol concentrations were studied after a single intraperitoneal injection of inhibin antiserum in 5-day-cyclic rats. Control rats received (non-immune) serum from castrated sheep or saline. Rats were injected at 10.00 h on dioestrus-1 (D1), i.e. the day following the day of oestrus, or at 17.00 h on dioestrus-2 (D2). The ovaries were excised at necropsy 48 h after injection, or at first or second oestrus after injection. After routine histology fresh corpora lutea were counted and/or differential follicle counts were made. Results from rats injected with either (non-immune) serum from castrated sheep or with saline were not different and were therefore combined to form the control group. The activity of inhibin-neutralizing antibodies in the circulation of antiserum-treated rats was reduced by approximately 39% between 8 h and second oestrus after injection, as determined by the binding of purified bioactive radioiodinated 31 kDa bovine inhibin. Rats were injected on D1 and killed at first oestrus. The number of fresh corpora lutea was significantly higher in antiserum-treated rats than in controls (13·9±0·4 vs 11·8±0·4; P < 0·05). Other rats injected on D1 were killed either 48 h or at the second oestrus after injection. Blood was collected 8, 16, 24 and 48 h and at first and second oestrus after injection. At 48 h after injection differential follicle counts showed that the ovaries of antiserum-treated rats contained approximately 32 more healthy follicles and 11 fewer atretic follicles than controls (both P < 0·05 vs control; data for follicles with volume > 100 × 105μm3 and diameter > 260 μm). The ovaries of the antiserum-treated group collected at second oestrus contained more corpora lutea than controls (17·5±0·5 vs 13·6±0·4; P < 0·001). Serum FSH levels at 8, 16, 24 and 48 h after antiserum injection were elevated (P < 0·05). Overall oestradiol levels in antiserum-treated rats were increased from 8 to 24 h and at first oestrus (P < 0·05) as compared with control rats. Further rats were injected on D2 and necropsied at first or second oestrus which caused ovulation rate to almost double at first oestrus (antiserum 23·7±1·4 vs control 12·4±0·4; P < 0·01), while at second oestrus there was no difference between antiserum-treated and control rats. The rise in FSH level after injection of antiserum on D1 caused follicle recruitment in addition to that normally occurring on the morning of oestrus (36 h earlier) and reduced atresia, resulting in a moderately increased ovulation rate on the first and second oestrus after injection. If the interval between antiserum injection and the next oestrus was shortened (injection on D2), ovulation rate was doubled, while on the next oestrus (second) there was no difference compared with controls. It is concluded that inhibition is progressively involved in the control of follicle growth and ovulation rate via its effect on serum FSH levels during the oestrus cycle of the rat. Journal of Endocrinology (1991) 130, 297–303

POSSIBILITY TO REDUCE THROMBOCYTOPENIA AFTER CHEMORADIOTHERAPY IN ONCOLOGICAL PATIENTS

2017 ◽  
Vol 63 (3) ◽  
pp. 466-469
Author(s):  
Luiza Korytova ◽  
Aleksey Meshechkin ◽  
Oleg Korytov ◽  
V. Krasnikova
Keyword(s):  
Combined Treatment ◽  
Treated Group ◽  
Median Number ◽  
Blood Analysis ◽  
Control Group ◽  
Level Control ◽  
Normal Range ◽  
Oncological Patients ◽  
Level Increase ◽  
And Control

Objective was to establish efficiency of sodium nucleospermat in correcting thrombocytopenia after chemoradiotherapy in oncological patients. Methods and materials. The study included data on 32 patients that had undergone combined treatment from January till May 2016. After detecting thrombocytopenia patients were randomized into two groups (16 patients in each): treated group, where patients received sodium nucleospermat, and control group, where sodium nucleospermat was not used. Thrombocyte level control was done on 5th, 10th and 15th day after treatment was over. Results and discussion. All 16 patients showed positive dynamics in increasing thrombocyte level after Sodium nucleospermat injection course was finished. This was proven by first (5th day) blood analysis. On average thrombocyte level after sodium nucleospermat treatment has risen to normal, at 161х109/1. Only 3 patients from this group had to pause radiotherapy for 5 days. Control group patients, which did not receive sodium nucleospermat, showed evidence of thrombocyte level recovery by 10th day only. On average thrombocyte level increase was insignificant, and median number was 111*109/l. Low thrombocyte level was main reason to pause radiotherapy for 11 (69%) patients in control group. Conclusion. Sodium nucleospermat allowed raising thrombocyte level to the lower normal range, which surpassed by 40%-50% in control group patients. Use of sodium nucleospermat did not show any cases of allergic reactions, toxicity or complications in oncological patients.

Passively immunizing ewes against inhibin during the luteal phase of the oestrous cycle raises the plasma concentration of FSH

1989 ◽  
Vol 123 (3) ◽  
pp. 383-391 ◽  
Author(s):  
G. E. Mann ◽  
B. K. Campbell ◽  
A. S. McNeilly ◽  
D. T. Baird
Keyword(s):  
Plasma Concentration ◽  
Luteal Phase ◽  
Passive Immunization ◽  
Oestrous Cycle ◽  
Ovulation Rate ◽  
Control Group ◽  
Pituitary Cells ◽  
Marked Rise ◽  
Peripheral Plasma

ABSTRACT Passive immunization was used to investigate the importance of inhibin in the negative feedback loop regulating the production of FSH in sheep. An antiserum raised to the 1–26 peptide fragment of the N-terminus of the α-chain of porcine inhibin was first shown to neutralize the suppressive effects of inhibin on the production of FSH by dispersed ovine pituitary cells in vitro. Groups of five mature Scottish Blackface ewes on day 8 of the luteal phase of the oestrous cycle were then injected with either 10 ml plasma from normal ewes (control) or 10 ml ovine inhibin antiserum. On day 10, luteal regression was induced by an i.m. injection of cloprostenol (100 μg), and ovulation rate determined 6 days later by laparoscopy. Peripheral plasma samples were collected throughout the experimental period. Following treatment, there was no change in the peripheral plasma concentration of LH in either group. Following injection of the inhibin antiserum, the concentration of FSH rose significantly (P<0·001) compared with the control group. The concentration of FSH rose from 1·42 ± 0·06 to a maximum of 2·58 ± 0·23 (s.e.m.) μg/l by 5·6 ±0·9 h, this maximum lasting 9·0±1·1 h. By 32·8 ±6·9 h, the concentration of FSH had returned to pretreatment levels, while the titre of free antibody in the plasma of treated ewes was still high. In the treated ewes, there were one single and four double ovulations compared with three single and two double ovulations in the control group, indicating that the inhibin immunization may have resulted in an increase in ovulation rate. We conclude that the marked rise in the plasma concentration of FSH following injection of inhibin antiserum provides strong evidence that inhibin is an important factor in the regulation of FSH production by the pituitary gland at this time. Journal of Endocrinology (1989) 123, 383–391

scholarly journals Effect of an extract of Aloe vera on the biodistribution of sodium pertechnetate (Na99mTcO4) in rats

2009 ◽  
Vol 24 (5) ◽  
pp. 383-386 ◽  
Author(s):  
Cecília Maria de Carvalho Xavier Holanda ◽  
Monique Batista da Costa ◽  
Natália Chilinque Zambão da Silva ◽  
Maurício Ferreira da Silva Júnior ◽  
Vanessa Santos de Arruda Barbosa ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Aloe Vera ◽  
Treated Group ◽  
Control Group ◽  
Blood Levels ◽  
Control Groups ◽  
High Increase ◽  
Tropical Plant ◽  
And Control ◽  
The Brain

PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity (%ATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of %ATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.

scholarly journals Effects of proportional high-protein/low-carbohydrate formulated diet consumption in diabetic rats: Beneficial impact on glycemic and weight control

2020 ◽  
Vol 20 (07) ◽  
pp. 16984-16996
Author(s):  
MMC Anyakudo ◽  
◽  
DO Adeniji ◽  
Keyword(s):  
Body Weight ◽  
Wistar Rats ◽  
Treated Group ◽  
Morphological Features ◽  
High Protein ◽  
Control Group ◽  
Formulated Diet ◽  
Low Carbohydrate ◽  
Male Wistar Rats ◽  
And Control

The metabolic response to nutrient ingestion and the rate of digestion and absorption of nutrient molecules in bowel physiology plays an important role in the metabolic control of some human chronic non-infectious diseases. This experimentally-controlled designed nutritional study which lasted eight weeks aimed to determine the effects of proportional high-protein/low-carbohydrate (HP/LC) formulated diet on glycemic tolerance, glycemic control, body weight, organ weight and organ morphometry in healthy and diabetic adult male Wistar rats. Twenty-four male Wistar rats purchased from a disease-free stock were randomly categorized into four groups (n = 6, each) after two weeks acclimatization period in raised stainless steel cages with 6 mm2mesh floor and replaceable numbered blotters papers placed under each cage in a well-ventilated animal house. Animal groups include: Healthy control group (HC), Healthy treated group (HT), Diabetic control group (DC) and Diabetic treated group (DT. The animals were fed according to the experimental design with water ad libitumfor eight weeks. Diabetes was inducted with freshly prepared alloxan monohydrate solution (150 mg/kg bw, intraperitoneally). Body weights and fasting blood sugar concentrations were measured twice weekly, while oral glucose tolerance test was conducted on the last day of the eighth-week study and subsequently followed by organs extraction after anesthesia for weight and gross assessment. Proportional high-protein/low-carbohydrate formulated diet caused significant reduction in mean body weight of treated diabetic (DT: 22.6%; P= .001) and healthy (HT: 5.8%; P= .007) rats while the control animals on control diet recorded significant (P< .05) increase in body weight gain (DC: 12.4%; HC: 11.2%). Glycemic tolerance and control improved significantly in diabetic treated rats over that of the healthy treated rats. Gross morphometry of the extracted organs (kidneys, liver, heart, lungs, spleen and testes) revealed sustained normal morphological features without any visible lesion. In conclusion, consumption of proportional high-protein/low-carbohydrate formulated diet enhanced body weight reduction and sustained normal organ morphological features with good glycemic tolerance and control in experimental rats, suggesting its dietary potentiality, safety and suitability to ameliorate obesity-related diabetes.

A comparative study of the corpus luteum

1995 ◽  
Vol 7 (3) ◽  
pp. 303 ◽  
Author(s):  
RT Gemmell
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Secretory Granules ◽  
Hormonal Control ◽  
Egg Laying ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Embryonic Diapause ◽  
Alternative Reproductive Strategy ◽  
Uterine Development

The corpus luteum (CL) is a transitory organ which has a regulatory role in reproduction. Sharks, amphibians and reptiles have corpora lutea that produce progesterone which influences the rate of embryonic development. The egg-laying monotremes and the two major mammalian groups, eutherian and marsupial, have a CL that secretes progesterone. Most eutherians have allowed for the uterine development of their young by extending the length of the oestrous cycle and the CL or placenta actively secretes progesterone until birth. Gestation in the marsupial does not extend beyond the length of an oestrous cycle and the major part of fetal development takes place in the pouch. Where the extension of the post-luteal phase in the eutherian has allowed for the uterine development of young, the marsupial has extended the pre-luteal phase of the oestrous cycle and has evolved an alternative reproductive strategy, embryonic diapause. The mechanism for the secretion of hormones from the CL has been controversial for many years. Densely-staining secretory granules have been observed in the CL of sharks, marsupials and eutherians. These granules have been reported to contain relaxin, oxytocin or mesotocin, and progesterone. A hypothesis to suit all available data is that all hormones secreted by the CL are transported within such granules. In conclusion, although there are obvious differences in the mode of reproduction in the two main mammalian groups, it is apparent that there is a great deal of similarity in the hormonal control of regression of the CL and parturition.

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