THE GROWTH-STIMULATING EFFECT OF GROWTH HORMONE AND l-THYROXINE ON THE MAMMARY GLANDS AND UTERUS OF THE MOUSE

Flux, D. S.

doi:10.1677/joe.0.0150266

Cited by 8 publications

(3 citation statements)

References 2 publications

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“…Four inbred strains of mice maintained at the Massey University Small Animal Production Unit (SAPU) were crossed and interbred to provide genetic variation in the base population. These strains, and the period for which they have been inbred at the SAPU, are 'NOS' or 'White mice' (Flux, 1957), CHI (Flux & Munford, 1957) and TSA (Cockrem, 1959), 30 years; and C3H/He (Anon, 1987), 5 years. All mice were housed in one room with a constant light to dark ratio of 14h:10h and a temperature of about 20 °C.…”

Section: Methodsmentioning

confidence: 99%

Responses to divergent selection for plasma concentrations of insulin-like growth factor-1 in mice

Ht¹,

McCutcheon

Mackenzie

et al. 1989

Genet. Res.

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SummaryA divergent selection experiment with mice, using plasma concentrations of insulin-like growth factor-1 (IGF-1) at 42 days of age as the selection criterion, was undertaken for 7 generations. Lines were not replicated. To obtain sufficient plasma for the IGF-1 assay, blood from four individuals was volumetrically bulked to obtain a litter mean IGF-1 concentration. This necessitated the use of between family selection. Although inbreeding accumulated in a linear fashion in each of the high, control and low lines, the rates were different for each line (3·6, 1·6 and 5·3% per generation for the high, control and low lines, respectively). As a consequence, the effects of selection and inbreeding are confounded in this experiment. Divergence between the high and low lines in plasma concentrations of IGF-1 continued steadily until generation 5. In generations 6 and 7, there was a reduced degree of divergence and this contributed towards the low realized heritability value of 0.15 ± 0.12. Six-week liveweight showed a steady positive correlated response to selection for or against plasma concentrations of IGF-1 until generation 4 (high-low difference = 1·7 g = 12%). In generation 5, a substantial drop in 6-week liveweight in the low line relative to both the high and control lines occurred (high-low difference, 3·9; g, 25%). This difference was maintained until generation 7.This experiment suggests that genetic variation exists at 6 weeks of age in plasma concentrations of IGF-1 in mice. Furthermore, genetic covariation between plasma IGF-1 concentrations and liveweight at 6 weeks of age is likely to be positive. Further experiments have been initiated to examine these theories.

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Section: Methodsmentioning

confidence: 99%

Responses to divergent selection for plasma concentrations of insulin-like growth factor-1 in mice

Ht¹,

McCutcheon

Mackenzie

et al. 1989

Genet. Res.

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“…The mice were from the same colony (Flux, 1957), as those used previously for this type of work (Flux et al 1961). Females with body weights in the range 8-5-13-9 g were ovariectomized at 21-23 days of age and fed a diet of one part dried buttermilk powder to two parts wholemeal flour for 2 days before starting the experiment.…”

Section: Methodsmentioning

confidence: 99%

“…Such a method may be satisfactory if there are no changes in the oestrogenic sensitivity of mouse uteri with time. Changes in sensitivity to oestrogen have been observed, for example, with the mammary gland (Flux, 1957). The use of at least two doses of the standard in each experiment, as was done by Pope et al (1959), is safer and leaves only the question of whether sensitivity to different types of oestrogen changed differentially with time.…”

Section: Methodsmentioning

confidence: 99%

Estimation of oestrogenic activity in red clover (Trifolium pratense) using ovariectomized immature mice

Munford

Flux

1961

Journal of Dairy Research

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TWO experiments concerned with the testing of plant material for oestrogenic activity, utilizing vaginal reactions and uterine weight changes in immature ovariectomized mice are reported.In the first experiment the effects of varying the feeding period of an oestrogenic diet, containing 20 % of freeze-dried red clover, and of varying the interval between the last feeding of this diet and slaughter were investigated. In general, uterine weight increased linearly with increased period of feeding and decreased linearly with delay in slaughtering. A feeding period of 4 days was satisfactory for comparisons based on uterine weight. If vaginal reactions were also to be utilized a feeding period of not less than 6 days was desirable.In the second experiment the dose-response relationships of diethylstilboestrol, genistein and oestrogenic red clover were investigated. All materials were incorporated in the diet of mice, and the level of plant material was kept at 20 % of the mixed feed by adding inactive plant material where necessary. In general, either diethylstilboestrol or genistein could form a satisfactory standard for biological estimation of oestrogenic activity in red clover. Relative potencies based on uterine weight response and occurrence of vaginal opening and oestrus-type vaginal smears are given.The biological estimation of oestrogenic activity in plant material involves a number of problems. Among the most important of these are: the choice of an appropriate response in a given test animal, a suitable duration of treatment and a satisfactory reference standard. Biggers (1959), who has discussed the first of these problems, concluded that in mice vaginal cornification was more suitable than increase in uterine weight, because the former, unlike the latter, was a specific reaction to oestrogens. On the other hand, the uterine weight response has the advantage that it provides quantitative data. Flux, Munford & Barclay (1961) decided that, for initial screening purposes, uterine weight increase was more satisfactory because it was likely to show a response with low doses of oestrogens. Uterine weight increase has been commonly used to detect oestrogenic activity in plant materials (Cheng,

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Besonderheiten der Wirkungen der einzelnen Gestagene auf Morphologie und Funktion des Genitaltraktes

Lauritzen¹,

Lehmann²,

Elger³

et al. 1969

Die Gestagene

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THE GROWTH-STIMULATING EFFECT OF GROWTH HORMONE AND l-THYROXINE ON THE MAMMARY GLANDS AND UTERUS OF THE MOUSE

Cited by 8 publications

References 2 publications

Responses to divergent selection for plasma concentrations of insulin-like growth factor-1 in mice

Responses to divergent selection for plasma concentrations of insulin-like growth factor-1 in mice

Estimation of oestrogenic activity in red clover (Trifolium pratense) using ovariectomized immature mice

Besonderheiten der Wirkungen der einzelnen Gestagene auf Morphologie und Funktion des Genitaltraktes

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