High doses of catecholamines activate glucose transport in human adipocytes independently from adrenoceptor stimulation or vanadium addition

Table 1 Methylamine stimulation of hexose uptake in rat and human adipocytes is dependent on semicarbazide-sensitive amine oxidase

	Rat adipocytes with vanadate 0.1 mmol/L	Human adipocytes without vanadium
Incubation condition	2-DG uptake (nmol/100 mg lipids/10 min)
Control	1.30 ± 0.12	0.49 ± 0.05
Insulin 100 nmol/L	13.08 ± 0.31e	1.49 ± 0.19e
Methylamine 1 mmol/L	11.27 ± 1.17e	0.86 ± 1.3b
Met + pargyline 1 mmol/L	6.37 ± 0.88f	0.84 ± 0.09
Met + semicarbazide 1 mmol/L	1.32 ± 0.19f	0.60 ± 0.08c
Met + pargyline + semicarbazide	1.18 ± 0.34f	0.59 ± 0.07d

Glucose uptake was assayed for 10 min after 45-min incubation with the indicated doses of agents. Mean ± SE of the mean of 8-9 rat and 18 human adipocyte preparations. Difference between insulin or methylamine and control significant at:

^aP < 0.05.

^bP < 0.01.

^eP < 0.001.

Significantly different from methylamine alone at:

^cP < 0.05.

^dP < 0.01.

^fP < 0.001.

2-DG: 2-Deoxyglucose; Met: Methylamine.