Effects of depilatory doses of epidermal growth factor on subsequent fertility, pregnancy rate and lambing performance in Merino ewes

1994 ◽  
Vol 45 (2) ◽  
pp. 333 ◽  
Author(s):  
BW Brown ◽  
PR Stockwell ◽  
BA Panaretto
Keyword(s):  
Body Weight ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Pregnancy Rate ◽  
Genetically Engineered ◽  
Dose Rates ◽  
Expected Time ◽  
Subsequent Fertility ◽  
Retention System ◽  
Epidermal Growth

In the present study on Merino ewes, murine epidermal growth factor (mEGF) and genetically engineered methionine epidermal growth factor (met-EGF), given at depilatory dose rates (120 8g mEGF/kg body weight (n = 82) and 250 8g met-EGF/kg body weight (n = 100) respectively), were assessed for effects on fertility, pregnancy rate and lambing performance. Following EGF injection, the ewes were fitted with a net retention system to hold the fleece on the animals for 5 weeks, at the end of which time the wool was harvested from the EGF-treated ewes by hand and was shorn conventionally from non EGF-treated controls (n = 100). All ewes were then joined to raddled-harnessed entire rams (2%) for 6 weeks. The dates of raddle markings recorded during the teaser period and during joining to entire rams revealed that the majority (97%) of control ewes were in oestrus at expected times during the joining period, whilst significantly (P < 0.001) fewer ewes in the mEGF (75%) and the met-EGF (65%) treated groups exhibited oestrus at the expected time. The majority of the ewes that were delayed in onset of oestrus were at the mid to late luteal stages of the oestrous cycle at the time of EGF treatment. There was no material difference between the three groups in the number of ewes returning to service during the joining period, or in the number of empty ewes. The three groups were also similar in the proportions of ewes bearing single or twin lambs, in the overall lambing percentage (controls 108010, mEGF 109%, et-EGF 107%) and survival of lambs to weaning. No abnormalities were found in any of the lambs. It appears that an interval of 5 weeks between dosing and joining is sufficient time for EGF-treated ewes to resume normal cyclicity and fertility.

Effect of epidermal growth factor on glucosamine-6-phosphate synthetase activity in the colon of neonatal mice

1985 ◽  
Vol 105 (2) ◽  
pp. 197-200 ◽  
Author(s):  
M. Hiramatsu ◽  
M. Kashimata ◽  
N. Minami ◽  
N. Minami ◽  
M. Kumegawa
Keyword(s):  
Body Weight ◽  
Enzyme Activity ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Colonic Mucosa ◽  
Single Injection ◽  
Synthetase Activity ◽  
Apparent Effect ◽  
Neonatal Mice ◽  
Epidermal Growth

ABSTRACT Epidermal growth factor (EGF), administered subcutaneously to neonatal mice at daily doses of 1, 2 and 4 μg/g body weight for 3 days, significantly increased glucosamine-6-phosphate synthetase activity in the colon. A single injection of EGF at doses of 2 and 4 μg/g body weight also significantly increased enzyme activity. When administered to mature mice, EGF (4 μg/g body weight for 3 days) had no apparent effect on the enzyme activity. From these results, we suggest that EGF acts as a trophic factor for the maturation of the colonic mucosa of neonatal mice. J. Endocr. (1985) 105, 197–200

Effect of mouse epidermal growth factor on fertility in rams

1990 ◽  
Vol 41 (6) ◽  
pp. 1147 ◽  
Author(s):  
BW Brown ◽  
PE Mattner ◽  
BA Panaretto ◽  
GH Brown ◽  
BD Gream ◽  
...  
Keyword(s):  
Body Weight ◽  
Survival Rate ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Post Treatment ◽  
Sperm Production ◽  
Teratogenic Effects ◽  
Progressive Motility ◽  
Epidermal Growth ◽  
Daily Sperm Production

Seminal characteristics and flock fertility were studied in Merino rams treated with mouse epidermal growth factor (EGF). Intravenous infusions of 105 8g EGF/kg body weight over 24 h in five rams had no statistically significant effect on daily sperm production measured from 6-10 weeks after dosing or on the percentages of spermatozoa that were unstained (nigrosinleosin stain) or morphologically normal. At 7-8 weeks post treatment, the percentage of spermatozoa exhibiting progressive motility was significantly reduced (P<0.05). By 9-10 weeks after treatment, the seminal characteristics were normal in all rams. In 1987, eight rams and in 1988, six ofthe same rams, were joined with ewes for 6 weeks (at a rate of 2%) 12 weeks after s.c. injection of 150 8g/kg body weight. Compared with the performance of control rams, EGF had no significant effect on ram fertility, nor did it produce any teratogenic effects in their progeny or effect their survival rate.

Some effects of epidermal growth factor at three stages of pregnancy in Merino ewes

1991 ◽  
Vol 42 (8) ◽  
pp. 1301
Author(s):  
IG Hazelton ◽  
BA Panaretto ◽  
PR Stockwell ◽  
JT Marshall ◽  
CD Nancarrow
Keyword(s):  
Body Weight ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Gestational Age ◽  
Untreated Control ◽  
Induced Abortion ◽  
Mechanisms Of Action ◽  
Plasma Progesterone ◽  
Epidermal Growth ◽  
Three Stages

Pregnant Merino ewes were treated with 90 8g murine epidermal growth factor (EGF) per kg body weight at either 25 (n = 80), 50 (n= 40) or 75 (n =40) days of gestation. Untreated control ewes were included at each gestational age (n=20, 12 and 12 respectively). Fifteen and twenty per cent of the ewes treated with EGF at days 25 and 50 respectively failed to lamb, significantly more (P < 0.01 ) than in ewes treated at day 75, where only one ewe failed to lamb, and in control ewes which all lambed. These differences were not reflected in significant differences between the overall percentage of lambs born in each group, as the incidence of abortion in single-bearing ewes was higher than in ewes carrying multiple fetuses. All lambs born alive to EGF-treated ewes appeared normal. Plasma progesterone concentrations measured before treatment and at 8, 24 and 48 h after EGF injection fell significantly in treated ewes relative to controls (P<0.01 at day 25; P<0.05 at days 50 and 75) and concentrations were lowest at 8 and 24 h after injection in those ewes which aborted. Following EGF treatment at days 25 and 50 of gestation, abortion occurred in all ewes with very low plasma progesterone concentrations 8 to 48 h after EGF injection, probably as a result of EGF-induced luteolysis. In other ewes plasma progesterone concentrations returned to pretreatment values by 48 h, indicating incomplete luteolysis. The delayed abortion observed in some of these ewes further suggests that other mechanisms of action are involved in EGF-induced abortion.

Plasma concentrations and urinary excretion of mouse epidermal growth factor associated with the inhibition of food consumption and of wool growth in Merino wethers

1982 ◽  
Vol 94 (2) ◽  
pp. 191-202 ◽  
Author(s):  
B. A. Panaretto ◽  
G. P. M. Moore ◽  
D. M. Robertson
Keyword(s):  
Body Weight ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Food Consumption ◽  
Proliferative Activity ◽  
Dose Range ◽  
Plasma Concentrations ◽  
Inhibitory Effects ◽  
Wool Growth ◽  
Epidermal Growth

Twenty-four adult Merino wethers were given mouse epidermal growth factor (mEGF) subcutaneously at doses ranging from 0·02 to 0·12 mg/kg body weight or intravenously in the dose range 010 to 0·14 mg/kg body weight for periods ranging from 3 to 48 h. Plasma concentrations of mEGF were measured by radioimmunoassay and effects of treatment on food consumption and wool growth were observed. Plasma concentrations of the protein sustained for 15–24 h at about 20 ng mEGF/ml (or exceeding this) almost invariably caused feed rejection and casting of the fleeces. This last result clearly indicated disruption of proliferative activity among the replicating cells in wool follicles which regulate wool growth. The inhibitory effects on appetite and wool growth of smaller doses of the protein and of plasma concentrations equal to those above which were sustained for shorter periods have also been examined. Approximately 10% of the dose of mEGF appeared in the urine of three sheep 1 to 3 days after the start of s.c. infusions of 5 mg for 7 h.

Ontogenesis of epidermal growth factor in liver of BALB mice

1988 ◽  
Vol 255 (1) ◽  
pp. E28-E32
Author(s):  
N. P. Laborde ◽  
M. Grodin ◽  
G. Buenaflor ◽  
P. Brown ◽  
D. A. Fisher
Keyword(s):  
Body Weight ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Postnatal Life ◽  
Twofold Increase ◽  
Life After Death ◽  
Epidermal Growth ◽  
Males And Females ◽  
Liver Tissues

To characterize the ontogenesis of hepatic epidermal growth factor (EGF) metabolism in normal BALB mice, we measured serum and liver concentrations of EGF and liver concentrations of pre-pro EGF mRNA. Female and male animals were studied at 1, 2, 5, 7, and 10 wk of life. After death, body weight and length were measured, and serum and liver tissues were collected for EGF determinations. Immunoreactive serum EGF (means +/- SE) increased at 7 and 10 wk and was significantly higher (P less than 0.05) in males (465 +/- 58 and 683 +/- 120 pg/ml) than females (188 +/- 52 and 295 +/- 64 pg/ml). Liver EGF concentrations were low at 1, 2, and 5 wk, significantly increasing (P less than 0.01) at 10 wk to 179 +/- 36 vs. 268 +/- 49 pg/mg protein for females and males, respectively (female and male values were significantly different, P less than 0.01). Pre-pro EGF mRNA was examined at 1, 2, 3, 5, 7 and 10 wk. EGF message increased in liver to highest values at 10 wk in both males and females. There was a high correlation between serum and liver EGF concentrations during the first 10 wk (r = 0.97 and 0.85 for males and females, respectively) and a twofold increase in liver EGF mRNA between 3 and 10 wk of postnatal life. These results suggest that liver may be an important source of circulating EGF in developing BALB mice.

Involvement of epidermal growth factor in inducing adiposity of aged female mice

1995 ◽  
Vol 146 (3) ◽  
pp. 381-393 ◽  
Author(s):  
H Adachi ◽  
H Kurachi ◽  
H Homma ◽  
K Adachi ◽  
T Imai ◽  
...  
Keyword(s):  
Body Weight ◽  
Growth Factor ◽  
Food Intake ◽  
Epidermal Growth Factor ◽  
Subcutaneous Fat ◽  
Control Group ◽  
Surgical Removal ◽  
Mrna Levels ◽  
Female Mice ◽  
Epidermal Growth

Abstract Aged mice exhibit an increase in their body weight (BW), which is associated with fat deposit increase. Epidermal growth factor (EGF) concentration in the submandibular gland also increases with aging. We examined the effects of elevated EGF on the adiposity of aged female mice. Studies were started in two groups of animals consisting of sham-operated (n=10) and sialoadenectomized (n=10, Sx; surgical removal of the submandibular glands) mice at 8 weeks of age. Body weight gain and food intake were measured throughout 78 weeks of age in these two groups. Body weight was significantly less in the Sx group throughout 78 weeks, while food intake was not changed by Sx after 12 weeks of age. To examine further if EGF plays a role in the induction of adiposity in aged female mice, sham-operated animals were given 100 μl anti-EGF rabbit antiserum (anti-EGF group, n=5) or normal rabbit serum (control group, n=5) every 3 days, and Sx animals were given 5 μg/day EGF (Sx+EGF group, n=5) or saline (Sx group, n=5) from 78 weeks of age for 3 weeks. At 81 weeks of age, all animals of these four groups were killed, and carcass fat deposition and fat cell sizes were measured. Although the relative weights (weight ratio to BW) of the liver and kidney were not changed by Sx and anti-EGF treatment, the relative weights of mesenteric and subcutaneous fat tissues and adipocyte weights were significantly decreased in Sx and anti-EGF groups compared with the control group. Moreover, both acyl-CoA synthetase (ACS) and lipoprotein lipase (LPL) mRNA levels were significantly decreased by Sx or anti-EGF administration in mesenteric and subcutaneous fat tissues. On the other hand, EGF administration to Sx animals had no effect on BW, fat tissues and adipocyte weights, and ACS and LPL mRNA levels. The results, however, were consistent with the fact that adipose tissue EGF receptors were down regulated in Sx mice. These findings suggest that EGF may play a role in the induction of adiposity in aged female mice. Journal of Endocrinology (1995) 146, 381–393

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