The method of cellular immobilization and perfusion was applied to adipocytes. The lipolytic effect of isoprénaline, whose action is produced as a result of receptor-drug interaction, was followed. An agarose solution kept at at 37 °C was mixed 1:1 with the cell suspension. Thereafter, adipocytes were immobilized in the agarose threads. The lipolytic effect of 0.1 ml of isoprénaline (1x10~4 mol/1), that was rapidly introduced to the cell perfusion inlet in a non-recirculating system, was monitored by assessing glycerol production. The immobilized and perfused adipocytes exhibited significant lipolytic activity. After reaching the maximum effect, 0.1 ml of propranol (lxl 0-3 mol/1) that was applied to the bioreactor inlet, abolished the isoprénaline effect. The present data demonstrate the potential applicability of immobilized perfused adipocytes for various kinds of studies.
To study the nature of adrenergic stimulation of ions and water reabsorption in the newt renal distal tubule, stationary microperfusion of the nephron and electron probe analysis were used. After application of norepinephrine (NE 10'6 M) to the tubule surface, the fractional reabsorption of fluid increased from 15.0±3.1 to 41.30±10.4 % (n = 7, p<0.01), of Na+ from 69.30 ±6.6 to 79.10±7.5 % (p<0.05), CT from 63.30±7.6 to 72.40 ±7.9 % (p<0.05). Instead of secretion (control), there was reabsorption of K+. Fractional reabsorption of Ca2+ decreased from 51.00±6.0 to 43.00±7.0 % (p<0.05). The nonspecific alpha-adrenergic antagonist dibenamine 10"6 M completely inhibited the effect of NE while, under the action of propranolol (2xl(76 M) NE increased ion and water reabsorption significantly. When applied alone, or with NE, the specific alpha2-adrenoblocker idazoxan, 2xl0‘6 M, did not interfere with reabsorption in the distal tubule. At the same time, under the action of alphai-adrenoblocker prazosin 2xl0'6 M NE, increased the fractional reabsorption of fluid from 24.10 ±3.4 to 44.40 ±4.0 % (n = 6, p<0.001). These results serve as evidence that there exist specific alpha^adrenoceptors in the newt distal tubule the stimulation of which increases membrane permeability of the distal tubule to water, Na+, K+, Cl', but not to Ca2+.