- Email: [email protected]
USA — Putative microvascular oxygen sensor
Biosensors & Bioelectronics Vol. I2 No. 1 (1997)
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reduction of in vivo sensitivity was not due to a local factor or factors but to a reversible alteration of the glucose sensor characteristics induced in vivo by some local factor(s). This suggests that modifications of the outer sensor membrane, the nature of which remains to be determined, may prevent this effect and resolve the problem. Contact: Service de Diabetologie, Hotel-Dieu, I Place du Parvis Notre-Dame, F75004 Paris, France. UK - Use of recombinant design of heroin sensor
DNA technology
in
In ANN. NEW YORK ACAD. SCI. (782/(534-543) 1996) D.A. Rathbone, P.-J. Halt., N.C. Bruce & C.R. Lowe of the Institute of Biotechnology report on ‘The use of recombinant DNA technology in the design of a highly specific heroin sensor’. No abstract given
Contact: Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 IQT, UK. USA - Putative microvascular oxygen sensor In CIRC. RES. (79/l (54-61) 1996) D.R. Harder,
J. Narayanan, E.K. Birks, J.F. Liard, J.D. Imig, J.H. Lombard, A.R. Lange & R.J. Roman of the Medical College of Wisconsin report on ‘Identification of a putative microvascular oxygen sensor’. The vascular response to changes in oxygen levels in the blood and tissue is a highly adaptive physiological response that &&ions to match tissue oxygen supply to metabolic demand. Defining the cellular mechanisms that can sense physiologically relevant changes in PO* and adjust vascular diameter are vital to an understanding of this process. A cytochrome P450 (P450) enzyme of the 4A family of omega-hydroxylases was localized in renal microvessels, renal cortex, and a striated muscle microvascular bed (crernaster) of the rat In the presence of molecular oxygen, this P450 enzyme catalyzes formation of 20-HETE from
,.,., ,.,......
.i,.,.,.,.,.,.,.,.,.,
arachidonic acid (AA). Prior studies have shown that 20-HETE potently contracts renal and cerebral arteries and arterioles. The present study demonstrates that 20-I-IETE constricts striated muscle arterioles as well. In both intact renal microvessels and enriched renal critical microsomal enzyme prepamtions, the formation of 20-HETE was linearly dependent on PO, between 20 and 140 mm Hg. Homogenates of cremaster tissue produced 2O-oxygen. HETE when incubated with AA. They also expressed message for P450 4A enzyme, as determined by Southern and Western blots. Administration of 17-octadecynoic acid (17-ODYA), which is a P450 4A inhibitor, attenuated the constriction of third-order cremasteric arterioles in response to elevation of superfusion solution PO2 from -3 to 5 mm Hg to -35 mm Hg. 17-ODYA had no effect on basal vascular tone or response of cremaster arterioles to vasoactive compounds. These results demonstrate the P450 existence of omega-hydroxylase activity and 20-HETE fbrmation in the vasculature and parenchyma of at least two microvascular beds. The data suggest that a P450 enzyme of the 4A family has the potential to function as an oxygen sensor in m microcirculatory beds and to regulate arteriolar caliber by generating 20-HETE in an oxygen-dependent manner. Contact: Cardiovascular Research Center, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226, USA. USA - Real-time monitoring of II-adrenergic response in fibroblasts
reduced
In ANAL. BIOCHEM. (238/l (76-81) 1996) O.C. Ong, C. Van Dop, & B.K.-K. Fung of UCLA School of Medicine report on ‘Real-time monitoring of reduced D-adrenergic response in fibroblasts from patients with pseudohypoparathyroidism’. The activation of cell-surface receptors usually produces a transient increase of the extracelldar acidification rate in culture cells that can be detected with a biosensor-based instrument. The authors describe the application
xi
...............:.:.:.:.:.:.:.:.:.:.:,:.:.:.:.:.~~:.:.~:.:::::::: ~~~~~~ -:-. :.:j:.:.:.:.:.:.:.:.:.:.r.,,:.:.: .:.:.:.:.:.:.:...:.:.:.: ...................... E ,...,.,.......................,...,
reduction of in vivo sensitivity was not due to a local factor or factors but to a reversible alteration of the glucose sensor characteristics induced in vivo by some local factor(s). This suggests that modifications of the outer sensor membrane, the nature of which remains to be determined, may prevent this effect and resolve the problem. Contact: Service de Diabetologie, Hotel-Dieu, I Place du Parvis Notre-Dame, F75004 Paris, France. UK - Use of recombinant design of heroin sensor
DNA technology
in
In ANN. NEW YORK ACAD. SCI. (782/(534-543) 1996) D.A. Rathbone, P.-J. Halt., N.C. Bruce & C.R. Lowe of the Institute of Biotechnology report on ‘The use of recombinant DNA technology in the design of a highly specific heroin sensor’. No abstract given
Contact: Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 IQT, UK. USA - Putative microvascular oxygen sensor In CIRC. RES. (79/l (54-61) 1996) D.R. Harder,
J. Narayanan, E.K. Birks, J.F. Liard, J.D. Imig, J.H. Lombard, A.R. Lange & R.J. Roman of the Medical College of Wisconsin report on ‘Identification of a putative microvascular oxygen sensor’. The vascular response to changes in oxygen levels in the blood and tissue is a highly adaptive physiological response that &&ions to match tissue oxygen supply to metabolic demand. Defining the cellular mechanisms that can sense physiologically relevant changes in PO* and adjust vascular diameter are vital to an understanding of this process. A cytochrome P450 (P450) enzyme of the 4A family of omega-hydroxylases was localized in renal microvessels, renal cortex, and a striated muscle microvascular bed (crernaster) of the rat In the presence of molecular oxygen, this P450 enzyme catalyzes formation of 20-HETE from
,.,., ,.,......
.i,.,.,.,.,.,.,.,.,.,
arachidonic acid (AA). Prior studies have shown that 20-HETE potently contracts renal and cerebral arteries and arterioles. The present study demonstrates that 20-I-IETE constricts striated muscle arterioles as well. In both intact renal microvessels and enriched renal critical microsomal enzyme prepamtions, the formation of 20-HETE was linearly dependent on PO, between 20 and 140 mm Hg. Homogenates of cremaster tissue produced 2O-oxygen. HETE when incubated with AA. They also expressed message for P450 4A enzyme, as determined by Southern and Western blots. Administration of 17-octadecynoic acid (17-ODYA), which is a P450 4A inhibitor, attenuated the constriction of third-order cremasteric arterioles in response to elevation of superfusion solution PO2 from -3 to 5 mm Hg to -35 mm Hg. 17-ODYA had no effect on basal vascular tone or response of cremaster arterioles to vasoactive compounds. These results demonstrate the P450 existence of omega-hydroxylase activity and 20-HETE fbrmation in the vasculature and parenchyma of at least two microvascular beds. The data suggest that a P450 enzyme of the 4A family has the potential to function as an oxygen sensor in m microcirculatory beds and to regulate arteriolar caliber by generating 20-HETE in an oxygen-dependent manner. Contact: Cardiovascular Research Center, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226, USA. USA - Real-time monitoring of II-adrenergic response in fibroblasts
reduced
In ANAL. BIOCHEM. (238/l (76-81) 1996) O.C. Ong, C. Van Dop, & B.K.-K. Fung of UCLA School of Medicine report on ‘Real-time monitoring of reduced D-adrenergic response in fibroblasts from patients with pseudohypoparathyroidism’. The activation of cell-surface receptors usually produces a transient increase of the extracelldar acidification rate in culture cells that can be detected with a biosensor-based instrument. The authors describe the application
xi