The Isolation and Identification of Progesterone Obtained From Cows' Milk During Pregnancy

Darling, J. A. B.; Kelly, Richard; Laing, A. H.; Harkness, R. A.

doi:10.1677/joe.0.0540347

Cited by 26 publications

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“…The reliability criteria of the method have already been described (Darling et al 1972;Darling & Harkness, 1973). In this method a mixture of steroids is oxidized to the steroid ketones which are separated and estimated by gas chromatography.…”

Section: Animalsmentioning

confidence: 99%

“…A method was used which was designed to indicate the presence of a large number of free and conjugated steroids in milk. Progesterone has been isolated from cows' milk (Darling, Kelly, Laing & Harkness, 1972) and since estimates of the progesterone content of cows' milk may provide a pregnancy diagnosis test applicable at 20-25 days of pregnancy (Laing & Heap, 1971), further studies have been made of factors which affect progesterone levels.…”

Section: Introductionmentioning

confidence: 99%

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A Survey of the Steroids in Cows' Milk

Darling¹,

Laing²,

Harkness³

1974

Journal of Endocrinology

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SUMMARY A survey has been made of the steroids in cows' milk using a method for the group analysis of steroids. Serial studies during and after pregnancy showed changes in progesterone concentration consistent with known variations in plasma concentrations. More progesterone was obtained from samples taken at the later stages of milking and samples obtained in the evening generally contained more progesterone than morning samples. Steroids were concentrated in the cream. Relatively constant levels of 5α-androstane-3,17-dione were found and it is suggested that this steroid is of adrenal origin. The predominance of 5α steroids in milk suggests that these are derived, at least in part, from metabolism in the mammary gland. The possible use of these findings in diagnosis of pregnancy and in studies of the hormonal control of lactogenesis is indicated.

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Section: Animalsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Survey of the Steroids in Cows' Milk

Darling¹,

Laing²,

Harkness³

1974

Journal of Endocrinology

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“…Various peptide (Baram et al, 1977;Malven, 1977;Sack et al, 1979) and steroid (Shemesh et al, 1979;Darling et al, 1972;Erb et al, 1977) hormones are found in milk.…”

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confidence: 99%

Concentrations and origin of oxytocin in breast milk.

1986

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“…The presence of progesterone in milk has been demonstrated (Darling et a!., 1972). Its correlation to corpus luteum function and peripheral plasma values was established, allowing the development of a milk-progesterone radioimmunoassay (RIA) for fertility control in cattle (Heap et al, 1973;Hoffmann and Hamburger, 1973;Ginther et al, 1974;Gunzler et al, 1975;Hoffmann et al, 1976).…”

Section: Gloria E Hoffmanmentioning

confidence: 99%

Abstracts

1977

Journal of Toxicology and Environmental Health

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In an effort to increase the scope of information relevant to the symposium and in order to provide individuals having limited or recently acquired data an opportunity to make a direct contribution to the meeting, a poster session was scheduled for the 1976 NCTR Hormone Research Symposium. The data exhibited and information provided at the poster session made a significant contribution to the scientific quality of the symposium.In addition to preparing posters, exhibitors submitted abstracts to be published with the symposium proceedings. As these abstracts represent diverse activities within the scope of hormone research, they are not easily categorized and therefore are published in alphabetical order according to senior authors.17α-Hydroxyprogesterone caproate was injected into 24 newborn female mice of the ICR strain for the first 5 days of life. Sesame oil was given to controls. Eleven animals from each group were ovariectomized at 40 days of age. Vaginal smears were done on all experimental and control animals for 10 days prior to sacrifice at 60 days of age. Effects of the neonatal hormone injection on vaginal epithelium were studied on histological sections of the vaginas.Six of 13 (46%) of the intact treated mice showed persistent estrus-like pictures in vaginal smears. Histologic examination revealed areas of increased proliferation of the vaginal epithelium in both the intact (group 1) and the ovariectomized (group 2) neonatally treated animals. Epithelial downgrowths into the stroma were noted in 4 of the 13 group 1 animals and 4 of the 11 group 2 animals. Also, 5 mice from group 1 and 9 from group 2 showed stimulation and overgrowth of mucin-containing cells on the surface of the vaginal epithelium.This preliminary study suggests that neonatal 17a-hydroxyprogesterone caproate injection (1) can cause ovary-dependent persistent vaginal cornification, and (2) is associated with both ovary-dependent and ovary-independent vaginal epithelial changes in 60-day-old mice.Concretions of calcium carbonate normally appear in vaginal washings every third and fourth day of the 4 day hamster estrous cycle and from the third day to the end of pregnancy and pseudopregnancy. Spherical concretions of vaterite (V) and hexogonal concretions of calcite (C) predominate over dumbbell-like concretions of aragonite (A) during the 4 day cycle. The latter predominate during pregnancy and pseudopregnancy. Concretions disappear after ovariectomy and reappear during daily sc injections of both estradiol-17/J (E) and progesterone (P), neither hormone alone being effective (Alleva et al., 1971). Here we report our first attempt to determine least effective doses of E and P. Hamsters (Mesocricetus auratus) were bilaterally ovariectomised and 2 wk later, when they were 110-113 days old and weighed 112-170 g, they were given the first of four daily sc injections of E and P dissolved in Mazola corn oil. The hormones were injected separately in 0.05 ml. Vaginal washings were obtained daily and were examined under a microscope (100X). Th...

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The Isolation and Identification of Progesterone Obtained From Cows' Milk During Pregnancy

Cited by 26 publications

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A Survey of the Steroids in Cows' Milk

A Survey of the Steroids in Cows' Milk

Concentrations and origin of oxytocin in breast milk.

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