Regulation of Energy Balance in the Golden Hamster

Borer, Katarina T.

doi:10.1007/978-1-4757-0815-8_15

Cited by 18 publications

(8 citation statements)

References 178 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The foetal testis produces measurable amounts of steroid hormone, whereas the foetal ovary is quiescent (Clemens & Witcher, 1985). Castration before or after puberty in the male hamster leads to an increase in body weight and somatic growth, but has little or no effect on growth in the female, and testosterone administration causes catabolic effects, regardless of food intake or activity (Borer, 1985).…”

Section: Discussionmentioning

confidence: 99%

Role of progesterone in mediating stress-related litter deficits in the golden hamster (Mesocricetus auratus)

Pratt¹,

Lisk²

1991

Reproduction

View full text Add to dashboard Cite

Primiparous females were mated to proven breeders and half received a subcutaneous implantation of a progesterone-filled silastic capsule on Day 3 which was removed on Day 14. The other half of the group received no treatment. Blood samples were taken from all individuals on Days 3, 7, 11 and 14. The females were paired for brief periods on Days 4, 5 and 6 with a conspecific matched for treatment group, age, weight and stage of pregnancy. Controls were exposed to a novel area instead of a conspecific. Within each of the pairs, one female was consistently dominant to the other. At parturition, all pups were counted, sexed and weighed. Among the untreated group, there were no significant differences between litter sizes or sex ratios (defined as percentage male) produced by control and dominant females. Subordinate females produced significantly smaller litters than control or dominant dams and significantly lower sex ratios than dominant dams. Subordinates produced fewer males than control or dominant dams, but there were no differences in the number of females produced. Among animals given progesterone implants, there were no significant reductions in litter size or sex ratio produced by subordinate dams compared with control or dominant dams. This study showed that female golden hamsters exposed to social subordination early in pregnancy produced smaller and more female-biased litters, and that these effects were accompanied by a significant reduction in circulating progesterone concentrations. When subordinate females were given supplementary doses of progesterone before exposure to stress, they did not show significant litter deficits.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

Section: Discussionmentioning

confidence: 99%

Role of progesterone in mediating stress-related litter deficits in the golden hamster (Mesocricetus auratus)

Pratt¹,

Lisk²

1991

Reproduction

View full text Add to dashboard Cite

show abstract

“…The hamster fetal testis produces measurable amounts of steroid hormone, but the fetal ovary is quiescent (Clemens & Witcher, 1985). Gonadectomy before or after puberty in the male hamster leads to an increase in body weight and somatic growth, while it has little or no effect on growth in the female, and testosterone administration causes catabolic effects, regardless of food intake or activity (Borer, 1985). Sundell (1962) karyotyped hamster blastocyst cells immediately before implantation and reported a primary sex ratio of 64-3%, but because of differential prenatal mortality, the secondary sex ratio (at parturition) was 50-3%.…”

Section: Discussionmentioning

confidence: 99%

Effects of social stress during early pregnancy on litter size and sex ratio in the golden hamster (Mesocricetus auratus)

Pratt¹,

Lisk²

1989

Reproduction

View full text Add to dashboard Cite

Primiparous female hamsters were mated to proven breeders and stressed during early pregnancy. Females were housed singly throughout gestation except for Days 4, 5 and 6 when they were paired for 10-min intervals 3 times each day with another female matched for age, weight and day of pregnancy. Within each of the pairs, one female was consistently dominant to the other. Controls were exposed to a novel area instead of a conspecific. At parturition, all pups were counted, sexed and weighed. There were no significant differences between litter sizes or sex ratios (defined as % male) of control and dominant females. Litter sizes produced by control or dominant dams were significantly larger than those of subordinate dams, and litter sex ratios of dominants were significantly higher than those of subordinates. Subordinate dams produced fewer males than did dominant dams, but there was no difference in the number of females produced. Also, subordinate dams produced smaller pups than control dams. Examination of uterine implantation sites and fetal resorptions indicated that fetal loss occurred between Days 5 and 10 of pregnancy. These results suggest that subordinate dams produce smaller litters via selective resorption or spontaneous abortion of males in utero and that those males they do produce are smaller than those produced by dominant or control dams. We suggest that males are more susceptible in utero to effects of maternal stress in this species, and may require more maternal investment to survive to term.

show abstract

“…Indeed, dopamine has been demonstrated to be a participatory neurotransmitter in hypothalamic regulation of feeding and a variety of ergot D 2 dopamine agonists, includingbromocriptine, have anorexic activities (11). However, concluding that Ergoset reduced body weight via appetite suppression seems premature in light of the following circumstances: 1) absolute values of caloric intake cannot be ascertained with much accuracy in such an outpatient setting; 2) changes in energy expenditure during the study, which will influence body weight, were not determined; 3) most importantly, several previous studies in animals as well as postmenopausal women indicate that bromocriptine treatment can substantially reduce body fat store levels without influencing caloric intake (1,2,6,12). Bromocriptine may reduce body fat without influencing feeding by shifting metabolism away from lipo•• genesis (1,13) while substantially increasing protein turnover (2), which is a significant component of total energy expenditure (14,15).…”

Section: Figure 2-ejfect Of 18 Weeks Treatment With Ergoset Plus Instmentioning

confidence: 96%

Bromocriptine (Ergoset) Reduces Body Weight and Improves Glucose Tolerance in Obese Subjects

Cincotta¹,

Meier²

1996

Diabetes Care

119

View full text Add to dashboard Cite

show abstract

Regulation of Energy Balance in the Golden Hamster

Cited by 18 publications

References 178 publications

Role of progesterone in mediating stress-related litter deficits in the golden hamster (Mesocricetus auratus)

Role of progesterone in mediating stress-related litter deficits in the golden hamster (Mesocricetus auratus)

Effects of social stress during early pregnancy on litter size and sex ratio in the golden hamster (Mesocricetus auratus)

Bromocriptine (Ergoset) Reduces Body Weight and Improves Glucose Tolerance in Obese Subjects

Contact Info

Product

Resources

About