Vascular endothelial growth factor in the rat pituitary: differential distribution and regulation by estrogen

Abstract

Vascular endothelial growth factor

Hypoxia Inhibits Expression of Prolactin and Secretion of Cathepsin-D by the GH4C1 Pituitary Adenoma Cell Line

“…Because low concentrations of oxygen have previously been reported to stimulate the expression of angiogenic factors such as vascular endothelial growth factor (VEGF) in tumor cells (Minchenko et al, 1994;Shweiki et al, 1992) and because the GH3 cell line, parental to GH4C1 cells, expresses VEGF (Lohrer et al, 2001;Ochoa et al, 2000;Vidal et al, 2000b), we used RT-PCR to assay transcription of several forms of VEGF in GH4C1 cells in response to hypoxia. Transcription of both the 164 and 120 amino acid variants of VEGF was elevated in GH4C1 cells after hypoxic treatment for 12 hours ( Fig.…”

“…In this regard, VEGF levels increase in the pituitary gland during the development of estrogen-induced prolactinomas (Banerjee et al, 1997), and both VEGF164 and VEGF120 are up-regulated by estrogens in the pituitary gland and in the GH3 lactotroph cell line (Ochoa et al, 2000).…”

“…RNA (5 g) was reverse transcribed using M-MLV Reverse Transcriptase (Promega, Madison, Wisconsin) and random hexamers (Roche Applied Science, Indianapolis, Indiana). All PCR reactions and primers used for VEGF and the internal control, ribosomal protein L19, were done as described previously (Ochoa et al, 2000). Briefly, PCR reactions were performed using the following primers for VEGF: antisense primer 5'-GCTCTCTTGGGTGCACTGGA-3' and sense primer 5'-CACCGCCTTGGCTTGTCACA-3' (Nakamura et al, 1996), with expected sizes of 635, 563, and 431 bp for amplification of VEGF188, VEGF164, and VEGF120, respectively.…”

Expression and Distribution of Vascular Endothelial Growth Factor Receptor Flk-1 in the Rat Pituitary

“…An intrinsic intercellular communication network appears to be involved in the control of pituitary homeostasis, particularly with regard to gene expression and the production/secretion of anterior pituitary hormones (Arzt et al 1998(Arzt et al ,1999. VEGF is also an autocrine/paracrine molecule secreted by normal and neoplastic anterior pituitary cells (Banerjee et al 1997(Banerjee et al ,2000Lloyd et al 1999;Vidal et al 1999Vidal et al , 2000aOchoa et al 2000). Although unanswered questions remain regarding the functional signifcant of VEGF expression in the adenohypophysis, it is conceivable that VEGF plays a role both in the formation of pituitary portal vessels during fetal life and in maintenance of their differentiated state in mature animals (Ferrara et al 1992).…”

Id2 Mediates Tumor Initiation, Proliferation, and Angiogenesis in Rb Mutant Mice

“…There is wide acceptance of the notion that, beyond a critical size, the "angiogenic switch" is required for growth of the tumor mass. The intermediate lobe of the pituitary gland is poorly vascularized (41). However, Rb-null tumors undergoing rapid expansion became highly angiogenic (Fig.…”