Blood Flow in Portal Systems with Special Reference to the Rat Pituitary Gland

Lees, Peter; Lynch, David T.; Richards, Hugh K.; Lovick, A. H. J.; Perry, Sheila; Pickard, John D.

doi:10.1038/jcbfm.1992.16

Cited by 6 publications

(3 citation statements)

References 19 publications

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“…Blood flow supply to the pituitary ranges from 100 to 170 ml 100 g -1 min -1 depending on different species and is consistently high especially considering the small tissular mass [10,11]. In addition, cell proliferation seems globally fainted in adult pituitary.…”

Section: Discussionmentioning

confidence: 98%

Pituitary function and morphology in Fabry disease

et al. 2015

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Endocrine abnormalities are known to affect patients with Fabry disease (FD). Pituitary gland theoretically represents an ideal target for FD because of high vascularization and low proliferation rate. We explored pituitary morphology and function in a cohort of FD patients through a prospectic, monocentric study at an Academic Tertiary Center. The study population included 28 FD patients and 42 sex and age-matched normal subjects. The protocol included a contrast enhancement pituitary MRI, the assessment of pituitary hormones, anti-pituitary, and anti-hypothalamus antibodies. At pituitary MRI, an empty sella was found in 11 (39%) FD patients, and in 2 (5%) controls (p < 0.001). Pituitary volume was significantly smaller in FD than in controls (p < 0.001). Determinants of pituitary volume were age and alpha-galactosidase enzyme activity. Both parameters resulted independently correlated at multivariate analysis. Pituitary function was substantially preserved in FD patients. Empty sella is a common finding in patients with FD. The major prevalence in the elderly supports the hypothesis of a progressive pituitary shrinkage overtime. Pituitary function seems not to be impaired in FD. An endocrine workup with pituitary hormone assessment should be periodically performed in FD patients, who are already at risk of cardiovascular complications.

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Section: Discussionmentioning

confidence: 98%

Pituitary function and morphology in Fabry disease

et al. 2015

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“…However, since influx of calcium plays a key role in regulation of growth hormone secretion (Holl et al 1988;Rawlings et al 1991;Lussier et al 1991), it is tempting to speculate that a flow-dependent mechanism might play an important regulatory role in this secretion during different physiological and pathological conditions of blood flow through the gland. The anterior pituitary is highly vascular and receives a very high rate of blood flow (Page, 1982;Lees, Lynch, Richards, Lovick, Perry & Pickard, 1992) through a venous portal system, which divides into a dense network of sinusoidal capillaries (for illustrations see Bergland & Page, 1978;Wheater, Burkitt & Daniels, 1987). Adjacent to these sinusoidal capillaries, somatotrophs (and other pituitary cells) can be found, secreting their hormones into the perivascular or intercellular spaces (Shimada & Tosaka-Shimada, 1989).…”

Section: Possible Role Of the Flow Effectmentioning

confidence: 99%

Mechanosensitivity of voltage‐gated calcium currents in rat anterior pituitary cells.

Ben‐Tabou,

Keller,

Nussinovitch

1994

The Journal of Physiology

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Sensitivity of voltage‐activated calcium currents to flow‐induced mechanical stress was examined in enriched populations of rat anterior pituitary somatotrophs. Voltage‐activated calcium currents were recorded with the whole‐cell configuration of the patch‐clamp technique. Pituitary cells were exposed to flow (from pipettes) which was produced by a hydrostatic pressure of about 3 cmH2O. In 92% of the cells studied (n = 87 cells) flow reduced the amplitude of both low voltage‐activated (LVA) and high voltage‐activated (HVA) calcium currents. These effects of flow on calcium currents did not result from changes in either seal resistance or leak conductance of the cell and were dependent on the magnitude of flow. The effect of flow is selective. We found that LVA calcium currents were substantially more sensitive to flow than HVA calcium currents. Under constant flow conditions, LVA calcium currents were reduced by 57.6 +/‐ 29.6% (S.D.), whereas HVA currents (recorded from the same cells) were reduced by only 17.8 +/‐ 15.9% (S.D.). The effects of flow on calcium currents were associated with effects on their related calcium tail currents. Slowly deactivating calcium tail currents were reduced by 75.3 +/‐ 25.6% (S.D.), whereas rapidly deactivating calcium tail currents were reduced by 29.1 +/‐ 14.4% (S.D.). The effect of flow on calcium currents was not associated with any significant shift in the activation curves of the calcium currents (voltage range ‐60 to +30 mV), suggesting that the effect of flow is not voltage dependent. The effect of flow is not dependent on activation of calcium currents during the exposure to flow. Calcium currents which were evoked immediately after cessation of the exposure to flow were reduced in amplitude and recovered to control values. Possible mechanisms underlying the flow effect and possible physiological relevance of the effect on pituitary cells are discussed.

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“…and bilateral manipulation of the pituitary venous drainage system, which may lead to postoperative glandular venous congestion and dysfunction. 6,9,10 Considering the importance of the venous drainage system for the preservation of pituitary function, 11 we explored a modification of the classic technique using an endoscopic endonasal intradural pituitary hemitransposition technique that requires only unilateral manipulation of the pituitary gland and its venous system. In this article, we aim to describe the nuances of this technique and illustrate its applicability in different tumors.…”

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confidence: 99%

Intradural Pituitary Hemitransposition: Technical Note and Case Series Illustration

Almeida,

Finger,

Weber

et al. 2023

Operative Neurosurgery

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BACKGROUND AND OBJECTIVES: Lesions located in the retrosellar region, interpeduncular cistern, and petroclival region are among the most difficult to access in neurosurgery. Transcranial approaches are useful; however, the large distance between the surgeon and the lesion as well as the presence of major neurovascular structures surrounding the lesion may limit surgical exposure. A midline transsphenoidal route avoids transgression of the neurovascular plane and provides direct access to the interpeduncular cistern. To safely access the interpeduncular fossa, it requires mobilization of the pituitary gland. The pituitary hemitransposition technique permits mobilization of the gland, while preserving its venous drainage and arterial supply to the gland on one of its sides, preserving gland function. The authors aim to describe the intradural pituitary hemitransposition technique and to demonstrate its safe application for resection of skull base tumors in the retrosellar space. METHODS: The authors describe the surgical technique and illustrate its application in 5 cases of different types of skull base tumors, including a video demonstrating all the steps to perform this approach. In addition, the authors discuss the advantages and limitations of this technique compared with other approaches to the retrosellar space. RESULTS: The intradural pituitary hemitransposition technique was used to safely resect a chondrosarcoma, chordoma, craniopharyngioma, teratoma, and meningioma involving the parasellar and retrosellar spaces, while minimizing endocrine morbidity. We had one patient with mild, albeit permanent hyperprolactinemia and hypothyroidism after surgery. No other patients had permanent dysfunction related to surgery. CONCLUSION: The endonasal endoscopic intradural pituitary hemitransposition approach is an effective technique for resection of lesions located within the retrosellar and petroclival regions, allowing adequate exposure while potentially optimizing the preservation of the pituitary function.

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Blood Flow in Portal Systems with Special Reference to the Rat Pituitary Gland

Cited by 6 publications

References 19 publications

Pituitary function and morphology in Fabry disease

Pituitary function and morphology in Fabry disease

Mechanosensitivity of voltage‐gated calcium currents in rat anterior pituitary cells.

Intradural Pituitary Hemitransposition: Technical Note and Case Series Illustration

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