1 Purified membranes retaining a catecholamine responsive adenylate cyclase have been prepared from rabbit heart, lung and (pseudo-pregnant) uterus. 2 These preparations have the characteristics of plasma membranes and both heart and lung respond to P-adrenoceptor agonists in the order: (± )-isoprenaline > (-)-noradrenaline > (-)-adrenaline > ( + )-isoprenaline > salbutamol. The sensitivity of ...

This study was performed to distinguish central and peripheral a -adrenoceptors in the inhibition of rat pineal melatonin synthesis. The 2 rats received lipoor hydrophilic a -adrenoceptor ligand injections at middark; after 1 or 2 h the pineal melatonin contents were 2 measured. The lipophilic agonist medetomidine (100 mg/kg s.c.) suppressed the melatonin contents significantly, while the hydro...

Beta2-adrenoceptor agonists have been used as bronchodilators in the management of bronchial asthma and chronic obstructive pulmonary disease (COPD); however, there is evidence suggesting that beta2adrenoceptor agonist use may increase morbidity and mortality1. The long term beta-agonists, salmeterol and formeterol were introduced at the time of heightened concern about safety of beta2 agonist ...

Although the prevalence of overactive bladder (OAB) is similar in both male and female populations, females have a greater tendency to seek medical advice regarding their symptoms. A review of the evidence of therapy among women shows that a variety of modalities has been shown to be effective for symptom improvement in women with OAB. Bladder retraining/re-education should be considered for al...

In the dog saphenous vein (DSV), phenylephrine (PE) responses through alpha-1 adrenoceptors receptors are antagonized by both alpha-1 and alpha-2 receptor antagonists. Furthermore, pretreatment with chloroethylclonidine (CEC) eliminates prazosin binding but reduces rauwolscine binding by half (). In new functional experiments, the effects of preincubation with phenoxybenzamine (PBZ), an irrever...

β2-Adrenoceptor (β2-AR) agonists promote muscle growth. The aim of this study was to elucidate some effects of the selective β2-adrenoceptor agonist clenbuterol (CLB) on myoblast proliferation. We found that CLB induces cell cycle arrest in C2C12 myoblasts. This effect is partly due to the enhanced stability of p27, rather than the increased gene transcription via cAMP response element-binding ...

The aim of this study was to determine the contribution of beta-adrenoceptor activation in the reconstruction of the structural and functional organization of denervated skeletal muscle. beta-agonists, clenbuterol (1.2 mg/kg body weight) and isoproterenol (2 mg/kg body weight), administration (daily oral administration; maximum 7 days) to normal innervated rats as well as denervated animals cau...

On the basis of data obtained in rabbits, the imidazoline receptor ligand rilmenidine has been suggested to decrease blood pressure in humans by activating central a2A-adrenoceptors. A prerequisite for this hypothesis was the unproved assumption that rabbit and human a2A-adrenoceptors are equally activated by rilmenidine. Because a2A-adrenoceptors in the brain and on cardiovascular sympathetic ...

Compared with epinephrine, the relative intrinsic activity of a series of partial agonists to activate fusion proteins between the porcine alpha-2A adrenoceptor and the a-subunit of Gi1 was reduced after a single-point mutation (CysGly) in the G protein. Although UK14304 was close to a full agonist at the fusion construct containing wild-type (Cys)Gi1a, it was a partial agonist at that containi...