Selective alpha-1 and alpha-2 adrenergic agonists were used to test the hypothesis that both receptor subtypes increase transcellular Na+ transport in the nephron. Oxygen consumption (QO2) was used as an index of transcellular transport and provided a continuous dynamic record of the tubules' response to an agonist. Both alpha-1 and alpha-2 adrenoceptor agonists produced a linear dose-related i...

The purpose of this study was to determine whether both alpha 1- and alpha 2-adrenergic receptors exist on vascular smooth muscle of microvessels and whether adrenergic constriction of anatomically distinct microvascular segments is differentially subserved by either receptor subtype. The cremaster skeletal muscle of anesthetized rats was acutely denervated and suspended in a Krebs bath contain...

Both nonlinear and fractal properties of beat-to-beat R-R interval variability signal (RRV) of freely moving lizards (Gallotia galloti) were studied in baseline and under autonomic nervous system blockade. Nonlinear techniques allowed us to study the complexity, chaotic behavior, nonlinearity, stationarity, and regularity over time of RRV. Scaling behavior of RRV was studied by means of fractal...

The alpha 2 and beta 2 adrenergic receptors, both of which are activated by epinephrine, but which can be differentiated by selective drugs, have opposite effects (inhibitory and stimulatory) on the adenylyl cyclase system. The two receptors are homologous with each other, rhodopsin, and other receptors coupled to guanine nucleotide regulatory proteins and they contain seven hydrophobic domains...

Gender-related differences in brown adipose tissue (BAT) thermogenesis of 110-day-old rats were studied by determining the morphological and functional features of BAT. The adrenergic control was assessed by studying the levels of beta(3)- and alpha(2A)-adrenergic receptors (AR) and by determining the lipolytic response to norepinephrine (beta(1)-, beta(2)-, beta(3)-, and alpha(2)-AR agonist), ...

BACKGROUND AND AIMS COX-2 enzyme inhibition is responsible for the anti-inflammatory effects of NSAIDs, COX-1 for their effects upon the gastrointestinal system (GIS), along with other side effects. We investigated the relationship between COX levels and those adrenergic receptors known to play a role in gastroprotection and anti-inflammatory activity. METHOD The effects of adrenaline and pre...

We studied the respiratory and blood pressure responses to chemical stimulation of two regions of the ventral brainstem in mice: the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively). Stimulation of the RVLM by microinjections of the excitatory amino acid L-glutamate induced increases in diaphragm activity and breathing frequency, elevation of blood pressure (BP), and a sli...