Stilbestrol Feeding and Growth Hormone Stimulation in Immature Ruminants2

Struempler, Arthur W.; Burroughs, Wise

doi:10.2527/jas1959.181427x

Cited by 30 publications

(12 citation statements)

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“…It is important to bear in mind that all ewes were injected with oestrogen three days before injection of PGF2a and lor start of milking, and further, that exogenous oestrogen will increase the levels of growth hormone (Streumpler & Burroughs 1959) and prolactin (Fell et al 1972) in plasma of sheep.…”

Section: Discussionmentioning

confidence: 99%

Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F_2α

Field

Gow

McDowell

et al. 1979

New Zealand Journal of Agricultural Research

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A single subcutaneous injection of prostaglandin F J-initiated secretion of substanti~l quantities of milk when given to non-pregnant ewes with mammary glands developed by prior treatment with ovarian steroids. A dramatic but transient increase in the levels of prolactin and growth hormone in plasma was observed. Ewes injected with ergocryptine 24 h before injection of prostaglandin F2" produced lower, but not significantly lower, yields of milk, even though the levels of prolactin in plasma were reduced to negligible values, whereas there wai'> no effect on the increase in levels of growth hormone. Control ewes not injected with prostaglandin F~<, secreted only trivial volumes of milk, with levels of pr0lactin and growth hormone in plasma remaining low.

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Section: Discussionmentioning

confidence: 99%

Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F_2α

Field

Gow

McDowell

et al. 1979

New Zealand Journal of Agricultural Research

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“…Thus it is possible that oestrogen per se or a factor released by oestrogen, or both, may synergize with prolactin to give the lactogenic response. It is possible that growth hormone could synergize with prolactin and, indeed, it has been reported that exogenous oestrogeh increases levels of growth hormone in the blood of sheep (Streumpler and Burroughs 1959).…”

Section: Prolactin Concentrationmentioning

confidence: 99%

Artificial Induction of Lactation in Ewes: The Involvement of Progesterone and Prolactin in Lactogenesis

Fulkerson¹,

Hooley²,

McDowell³

et al. 1976

Aust. Jnl. Of Bio. Sci.

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An attempt has been made to evaluate the importance of prolactin and 'progesterone withdrawal' for lactogenesis. The experimental model system used was the ovariectomized, non-pregnant ewe induced to lactate artificially by treatment with trigger hormone (either oestrogen, glucocorticoid or oxytocin) alone or in combination with progesterone. It appears from the results that prolactin is important in the lactogenic responses elicited by oestrogen and oxytocin but not as important in the response elicited by glucocorticoid. Moreover, the results suggest that, in the ewe, an appropriate positive hormonal stimulus will overcome the inhibitory influence of progesterone on lactogenesis.

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“…Exogenous oestrogen caused a marked increase in the pituitary content of sth activity by Day 110 in hysterectomized pigs as compared with uninjected hysterectomized animals (Table 2). Diethylstilboestrol increased the weight of the adenohypophysis, the concentration of sth activity in the pituitary gland (Struempler & Burroughs, 1959) and the plasma level of growth hormone in cattle (Trenkle, 1970).…”

Section: Discussionmentioning

confidence: 99%

Changes in Adenohypophysial Cells and Levels of Somatotrophin and Prolactin at Different Reproductive Stages in the Pig

Anderson¹,

Peters²,

Melampy³

et al. 1972

Reproduction

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Percentages of cell types in the adenohypophysis were compared with the content of sth and prolactin at different reproductive stages (e.g. immature, oestrous cycle, pregnancy, lactation and after hysterectomy) in the pig. Acidophils represent sth and prolactin activities. Chromophobes are undifferentiated, inactive or depleted cells.Acidophils represented half (53\m=.\5%) the cell population. Percentages of sth cells were higher in 17-day-old pigs than in mature animals. This is a period of rapid growth in the young pig. During the cycle, during pregnancy and after hysterectomy, the percentages of prolactin cells were higher than those found in immature or lactating pigs.The chromophobes represented 13\m=.\1 % of the cell population. Chromophobes were the predominant cell type during lactation, but these seemingly inactive cells may have been active acidophils that were synthesizing and secreting prolactin. By rapid turnover of hormone, the cytoplasmic granules in prolactin cells lack differentiation.The sth activity was similar in pigs during pregnancy and lactation and after hysterectomy. There were no significant correlations in the percentages of sth cells and the concentration or content of sth during pregnancy and lactation. There was a trend of increased percentages of prolactin cells in later stages of pregnancy and after hysterectomy. Exogenous oestrogen caused a marked increase in the pituitary content of sth and prolactin in hysterectomized pigs as compared with uninjected hysterectomized animals. Prolactin levels remained relatively constant during pregnancy and after hysterectomy, but declined during lactation. Exogenous oestrogen caused a consistently higher trend in prolactin activity in hysterectomized animals.

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Stilbestrol Feeding and Growth Hormone Stimulation in Immature Ruminants2

Cited by 30 publications

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Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F_2α

Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F_2α

Artificial Induction of Lactation in Ewes: The Involvement of Progesterone and Prolactin in Lactogenesis

Changes in Adenohypophysial Cells and Levels of Somatotrophin and Prolactin at Different Reproductive Stages in the Pig

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Stilbestrol Feeding and Growth Hormone Stimulation in Immature Ruminants2

Cited by 30 publications

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Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F2α

Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F2α

Artificial Induction of Lactation in Ewes: The Involvement of Progesterone and Prolactin in Lactogenesis

Changes in Adenohypophysial Cells and Levels of Somatotrophin and Prolactin at Different Reproductive Stages in the Pig

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Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F_2α

Artificial induction of lactation in ewes: the importance of prolactin and growth hormone for initiation of lactation induced with prostaglandin F_2α