Hypophysial Blood Flow in Rats After Destruction of the Pituitary Stalk

David, M; Csernay, L.; László, Ferenc; Kovács, K.

doi:10.1210/endo-77-1-183

Cited by 16 publications

(3 citation statements)

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“…It is known that interruption of the portal vasculature results in extensive necrocsis of the pituitary (Daniel and Prichard, 1965;David et al, 1965). However, the anterior pituitaries were kept intact except occasional small central infarct following hypothalamic destruction in the present experiment.…”

Section: Plasma Prolactin Responses To 5-htp In Rats With Hypothalamimentioning

confidence: 54%

Effect of hypothalamic surgery on prolactin release induced by 5-hydroxytryptophan (5-HTP) in rats.

et al. 1976

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SynopsisIntravenous injections of varying doses of 5-HTP (1, 3 and 5mg/100g body wt), a precursor of serotonin, caused a significant and dose-related increase in plasma prolactin concentrations in urethane-anesthetized rats. Increases in plasma prolactin concentrations caused by 5-HTP (1mg/100g body wt iv) were abolished by the concomitant administration of L-DOPA (2mg/100g body wt iv). Plasma prolactin levels were also significantly elevated following the injection of 5-HTP in rats with complete hypothalamic deafferentation, whereas 5-HTP had no significant effect on plasma prolactin levels in rats with extensive hypothalamic ablation.These results suggest that 5-HTP causes prolactin secretion by stimulating the serotoninergic mechanism in the hypothalamus.

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Section: Plasma Prolactin Responses To 5-htp In Rats With Hypothalamimentioning

confidence: 54%

Effect of hypothalamic surgery on prolactin release induced by 5-hydroxytryptophan (5-HTP) in rats.

et al. 1976

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“…min-' g-1, assuming that the weight of this part of the pituitary gland was 10 mg. However, blood flow in the pars distalis as determined by the fractional distribution of rubidium (Goldman, 1963;David, Csernay, Laszlo & Kovacs, 1965) or by the hydrogen gas method (Porter, Hines, Smith, Repass & Smith, 1967), was 0-46, 0-76 and 0-64 ml. ming-', respectively.…”

mentioning

confidence: 98%

The luteinizing hormone releasing activity of extracts of blood from the hypophysial portal vessels of rats

Fink¹,

Harris²

1970

The Journal of Physiology

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1. A method of acid ethanol extraction and gel filtration was used to obtain a ;luteinizing hormone (LH)-free' fraction of blood collected from the cut pituitary stalk of rats (termed hypophysial portal blood).2. The ;LH-free' fraction of hypophysial portal plasma from hypophysectomized and from ovariectomized rats caused a greater depletion of ovarian ascorbic acid in immature rats, pretreated with gonadotrophins, than a similar fraction of systemic plasma obtained from the same donor animals.3. The ;LH-free' fraction of hypophysial portal plasma from ovariectomized rats evoked a rise in the level of LH in the systemic plasma of ovariectomized, oestrogen and progesterone treated, rats. This fraction also caused ovulation in rabbits when infused directly into the anterior pituitary gland of these animals. The activity of the ;LH-free' fraction of systemic plasma was considerably less than that of portal plasma in either of these assay systems.4. The results of these experiments suggest the presence of a factor in the ;LH-free' fraction of hypophysial portal plasma which is capable of causing the release of luteinizing hormone from the anterior pituitary gland. The molecular weight of this factor, as assessed by its behaviour on filtration through ;Sephadex G-25', is probably less than 5000.5. The LRF activity of the ;LH-free' fraction of hypophysial portal plasma obtained from rats at various phases of the oestrous cycle was measured by the ovarian ascorbic acid depletion method. There appears to be a decrease in the level of activity at oestrus. However, a rise in LRF activity, which was expected to occur at the ;critical period' of prooestrus, was not evident. The significance of these findings is discussed.

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“…The anterior pituitary is finely regulated by the hypothalamic modulators via the portal vessels. The consequences of severing the stalk on blood flow in the adenohypophysis are well documented (19). Functional stimuli also modify the blood flow in the anterior lobe: an in¬ crease by 67% was found by Goldman (5) in con¬ nection with acute stress.…”

Section: Tablezmentioning

confidence: 99%

Changes of blood flow in the adenohypophysis of normal and estrogen pretreated Fisher rats by tamoxifen

Stawowy

Kemeny²,

Jakubowski³

1989

Acta Endocrinologica

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Abstract. Blood flow was measured in the adenohypophysis and in the cerebral cortex of female F344 rats over a period of 90 min using the hydrogen clearance method. Tamoxifen, 1 mg/kg, administered iv reduced the blood flow in the adenohypophysis by 35%, whereas cerebral blood flow and arterial pressure remained unchanged. Seven days sc treatment with tamoxifen (1 mg/kg daily) had no demonstrable effect on blood flow. Anterior pituitary hyperplasia was induced in 15 rats with diethylstilbestrol containing implants. These rats responded to 7 days of sc tamoxifen treatment by 30% increase in adenohypophyseal blood flow. These results suggest that tamoxifen has a different effect on adenohypophysial circulation of the rat depending on whether it is administered in a low- or high-estrogen state.

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Hypophysial Blood Flow in Rats After Destruction of the Pituitary Stalk

Cited by 16 publications

References 1 publication

Effect of hypothalamic surgery on prolactin release induced by 5-hydroxytryptophan (5-HTP) in rats.

Effect of hypothalamic surgery on prolactin release induced by 5-hydroxytryptophan (5-HTP) in rats.

The luteinizing hormone releasing activity of extracts of blood from the hypophysial portal vessels of rats

Changes of blood flow in the adenohypophysis of normal and estrogen pretreated Fisher rats by tamoxifen

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