Multiple firm mobile swellings over the scalp.

Abstract

Sympathomimetic drugs and drugs that block adrenoceptors have important effects, some of which are of great clinical value. These effects vary dramatically according to the drug’s selectivity for  and  receptors.  1 and  2 adrenoceptors coexist in the heart of various animal species, including man. Competitive radio-ligand binding studies performed in membranes from homogenized hearts have shown that only 20-30% of the total β-adrenoceptors are of the β2-subtype in adult mammalian ventricular tissue. This number is even further reduced when purified cardiac myocytes rather than homogenized tissues are used. Unlike the mammalian heart, β-adrenoceptor population in the frog heart is composed of a majority (~ 80%) of β2-receptors. Frogs, weighing 150 – 250g, double pith a frog and fasten it to a frog board, ventral side up, midline incision was given on the abdomen. Pectoral girdle was removed and the heart was exposed, Pericardium was removed carefully ‘v’ shaped cut was given in inferior vena cava and the tip of syme’s cannula was passed into it. It was tied firmly with inferior vena cava to assure the cannula in place.