A note on melatonin-treated red deer stags advancing the onset of the calving season in hinds

1990 ◽  
Vol 51 (1) ◽  
pp. 213-216 ◽  
Author(s):  
M. W. Fisher ◽  
P. F. Fennessy
Keyword(s):  
Food Production ◽  
Red Deer ◽  
Factorial Experiment ◽  
Melatonin Treatment ◽  
Exogenous Melatonin ◽  
Breeding Activity ◽  
Calving Season

ABSTRACTThe effects of treating adult red deer hinds nutritional demands to coincide better with and stags with exogenous melatonin on the food production on improved pastures. One calving season in hinds were evaluated in a 2 such method has been the administration of × 2 factorial experiment. Treated stags were implanted with melatonin monthly beginning in December and hinds post calving in January, Melatonin advanced the timing of rutting behaviour in both treated stags. Calving date was significantly influenced by melatonin treatment of hinds (a mean 10-day advancement; P < 0·01) or stags (12-day advancement; P < 0·001). The interaction of hind and stag treatments was not significant, however treatment of both sexes resulted in the greatest advancement in mean calving date (21 days; P < 0·001). These results indicate that treatment of red deer hinds or stags with exogenous melatonin can result in an earlier calving season and suggest seasonally advanced stags can stimulate earlier breeding activity in hinds.

Effects of ageing and exogenous melatonin on pituitary responsiveness to GnRH in rats

Reproduction ◽  
2000 ◽  
pp. 151-156 ◽  
Author(s):  
E Diaz ◽  
D Pazo ◽  
AI Esquifino ◽  
B Diaz
Keyword(s):  
Body Weight ◽  
Reproductive System ◽  
Plasma Concentrations ◽  
Pituitary Hormones ◽  
Female Rats ◽  
Control Groups ◽  
Melatonin Treatment ◽  
Exogenous Melatonin ◽  
Reproductive Axis ◽  
Effect Of Age

The effect of age and melatonin on the activity of the neuroendocrine reproductive system was studied in young cyclic (3-5 months-old), and old acyclic (23-25 month-old) female rats. Pituitary responsiveness to a bolus of GnRH (50 ng per 100 g body weight) was assessed at both reproductive stages in control and melatonin-treated (150 micrograms melatonin per 100 g body weight each day for 1 month) groups. After this experiment, female rats were treated for another month to study the influence of ageing and melatonin on the reproductive axis. Plasma LH, FSH, prolactin, oestradiol and progesterone were measured. A positive LH response to GnRH was observed in both control groups (cyclic and acyclic). However, a response of greater magnitude was observed in old acyclic rats. Melatonin treatment reduced this increased response in acyclic rats and produced a pituitary responsiveness similar to that of young cyclic rats. FSH secretion was independent of GnRH administration in all groups, indicating desynchronization between LH and FSH secretion in response to GnRH in young animals and during senescence. No effect on prolactin was observed. Significantly higher LH (3009.11 +/- 1275.08 pg ml(-1); P < 0.05) and FSH concentrations (5879.28 +/- 1631.68 pg ml(-1); P < 0.01) were seen in acyclic control rats. After melatonin treatment, LH (811.11 +/- 89.71 pg ml(-1)) and FSH concentrations (2070 +/- 301.62 pg ml(-1)) decreased to amounts similar to those observed in young cyclic rats. However, plasma concentrations of oestradiol and progesterone were not reduced. In conclusion, the results of the present study indicate that, during ageing, the effect of melatonin is exerted primarily at the hypothalamo-pituitary axis rather than on the ovary. Melatonin restored the basal concentrations of pituitary hormones and pituitary responsiveness to similar values to those observed in young rats.

Effect and possible mechanisms of melatonin treatment on the quality and developmental potential of aged bovine oocytes

2017 ◽  
Vol 29 (9) ◽  
pp. 1821 ◽  
Author(s):  
Shuang Liang ◽  
Jing Guo ◽  
Jeong-Woo Choi ◽  
Nam-Hyung Kim ◽  
Xiang-Shun Cui
Keyword(s):  
In Vitro Fertilisation ◽  
Cortical Granule ◽  
Melatonin Treatment ◽  
Developmental Potential ◽  
Exogenous Melatonin ◽  
Atp Production ◽  
Quality Deterioration ◽  
Oocyte Aging ◽  
Bovine Oocytes

After reaching the metaphase II (MII) stage, unfertilised oocytes undergo a time-dependent process of quality deterioration referred to as oocyte aging. The associated morphological and cellular changes lead to decreased oocyte developmental potential. This study investigated the effect of exogenous melatonin supplementation on in vitro aged bovine oocytes and explored its underlying mechanisms. The levels of cytoplasmic reactive oxygen species and DNA damage response in bovine oocytes increased during in vitro aging. Meanwhile, maturation promoting factor activity significantly decreased and the proportion of morphologically abnormal oocytes significantly increased. Melatonin supplementation significantly decreased quality deterioration in aged bovine MII oocytes (P < 0.05). Additionally, it decreased the frequency of aberrant spindle organisation and cortical granule release during oocyte aging (P < 0.05). In the melatonin-supplemented group, mitochondrial membrane potential and ATP production were significantly increased compared with control. Furthermore, melatonin treatment significantly increased the speed of development of bovine oocytes to the blastocyst stage after in vitro fertilisation and significantly decreased the apoptotic rate in the blastocysts (P < 0.05). The expression of Bax and Casp3 in the blastocysts was significantly reduced after treatment with melatonin, whereas expression of Bcl2 significantly increased (P < 0.05). In conclusion, these findings suggest that supplementation of aged bovine oocytes with exogenous melatonin improves oocyte quality, thereby enhancing the developmental capacity of early embryos.

Delayed senescence of apple leaves by exogenous melatonin treatment: toward regulating the ascorbate-glutathione cycle

2011 ◽  
Vol 53 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Ping Wang ◽  
Lihua Yin ◽  
Dong Liang ◽  
Chao Li ◽  
Fengwang Ma ◽  
...  
Keyword(s):  
Melatonin Treatment ◽  
Exogenous Melatonin ◽  
Delayed Senescence ◽  
Apple Leaves ◽  
Glutathione Cycle

Exogenous melatonin treatment reduces hepatocyte damage in rats with experimental acute pancreatitis

2010 ◽  
Vol 17 (5) ◽  
pp. 682-687 ◽  
Author(s):  
Cavit Çöl ◽  
Kahraman Dinler ◽  
Oğuz Hasdemir ◽  
Oktay Büyükaşık ◽  
Güler Buğdaycı ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Melatonin Treatment ◽  
Experimental Acute Pancreatitis ◽  
Exogenous Melatonin ◽  
Hepatocyte Damage

An intraruminal soluble glass bolus containing melatonin — a potential system for early lamb production

1997 ◽  
Vol 1987 ◽  
pp. 25-25
Author(s):  
A.L. Poulton ◽  
A.M. Symons ◽  
M.I. Kelly ◽  
J. Arendt
Keyword(s):  
Seasonal Changes ◽  
Commercial Application ◽  
Economic Pressure ◽  
Melatonin Secretion ◽  
Melatonin Treatment ◽  
Neural Signal ◽  
Breeding Activity ◽  
Soluble Glass ◽  
Potential System ◽  
The Hours

Seasonal changes in daylength (photoperiod) are effectively monitored by the eye transmitting a neural signal to the pineal gland which responds by secreting a hormone, melatonin, during the hours of darkness. Decreasing daylength is accompanied by an increase in the duration of melatonin secretion and stimulates breeding activity in sheep.It has been demonstrated that both timed (afternoon feeding and injection) and continuous (subcutaneous and vaginal implant) administration of supplementary melatonin to ewes in mid-summer mimics the effect of short or decreasing photoperiod and can advance the onset of breeding activity. Such treatments can also increase relative fecundity at early mating by phase-advancing the mid-breeding season peak in ovulation rate. As the U.K. is not sufficient in lamb production and bearing in mind the economic pressure for early lamb marketing, effective melatonin treatment offers considerable potential for commercial application.

A note on the effect of melatonin feeding on the initiation of ovarian activity and on plasma prolactin levels in lactating and non-lactating red deer hinds

1985 ◽  
Vol 40 (3) ◽  
pp. 515-518 ◽  
Author(s):  
Rachel Nowak ◽  
R. N. Elmhirst ◽  
R. G. Rodway
Keyword(s):  
Detection Limit ◽  
Corpus Luteum ◽  
Red Deer ◽  
Inhibitory Effect ◽  
Ovarian Activity ◽  
Plasma Prolactin ◽  
Melatonin Treatment ◽  
Plasma Progesterone ◽  
Blood Samples

ABSTRACTMelatonin was fed daily at 14.00 h to eight non-lactating and six lactating hinds. Feeding was begun on 27 July 1983 (day 1) and continued until 21 September (day 57). Six non-lactating hinds were used as controls. Blood samples were taken about every 10 days from day 42 until day 73. Plasma progesterone and prolactin were determined by radioimmunoassay. Progesterone values of greater than 0·63 μg/1 were taken to indicate the presence of a corpus luteum and that the animal had ovulated. In the melatonintreated, non-lactating group seven of the eight hinds showed ovarian activity compared with two of the six controls (P < 0·01). None of the lactating hinds treated with melatonin showed evidence of ovarian activity. In both the lactating and non-lactating hinds treated with melatonin, prolactin levels were never greater than the detection limit of the assay (7·4 μg/l), while, in the control hinds mean prolactin levels were elevated on all but the last sampling day. It is, therefore, possible to induce early ovarian activity in non-lactating red deer hinds by feeding melatonin. However, although melatonin treatment similarly depressed plasma prolactin levels in both lactating and non-lactating hinds, it was unable to overcome the inhibitory effect of lactation on reproduction.

scholarly journals Effect of Exogenous Melatonin Treatment on the Reproductive Characteristics and Progeny of Male Rats Exposed to Different Periods From Light and Darkness

2017 ◽  
pp. 507-518 ◽  
Author(s):  
K. A. A. MAJRASHI ◽  
I. A. H. BARAKAT ◽  
A. R. AL-HIMAIDI ◽  
K. G. ADHAM
Keyword(s):  
Hormone Treatment ◽  
The Body ◽  
Female Rats ◽  
Male Rats ◽  
Testis Weight ◽  
Melatonin Treatment ◽  
Rat Serum ◽  
Exogenous Melatonin ◽  
Anti Oxidant ◽  
Harmful Effects

Light is an important environmental factor that controls the regulation of physiological functions of organisms. Melatonin is considered as one of the major hormones that play an important role in protecting body from many harmful effects and acts as a powerful anti-oxidant source to controlling the levels of antioxidant enzymes within the body. The main objectives of this work were to study the effect of 1) photoperiod changes and 2) exogenous melatonin hormone treatment on the sperm properties, body and testis weight, embryo characteristics, and concentration level of melatonin and testosterone in treated rat serum. This study has been conducted using thirty-six male rats and one hundred and twenty female rats. Animals were divided into six groups, each group containing six males and twenty female rats. Our results showed a significant influence of photoperiod changes on the melatonin and testosterone hormones concentration in rats’ serum, body weight only, while the other characteristics not affected. As for the effect of melatonin it has been found that the movement of sperm in GIII and IV, as well as embryos absorbed and newborns weight traits has been significantly affected, while the rest of the properties were not significantly affected by melatonin treatment.

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