caa a22 4500 469078081 CHVBK 20180323132941.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF00168734 doi (NATIONALLICENCE)springer-10.1007/BF00168734 Cholinergic sensitivity of irides from donors with various pathological conditions and lens implants [Elektronische Daten] [Popat Patil, Thomas Manger] Summary: In vitro, iris contractions after muscarinic agonists were measured in mg of tension change and the concentration producing 50% of the response was expressed as EC50 μmol/1. Although the average EC50 value of carbachol in the iris sphincter of the donors with diabetes or Parkinson's disease did not change significantly when compared with the control, the maximum contraction of the tissue from the diseased state was increased significantly. Thus, in addition to the well known denervation supersensitivity of the iris-dilator, the iris-sphincter also develops adaptive sensitivity changes. Antimuscarinic drug treatment in some Parkinson's patients interfered with the estimation of supersensitivity in vitro studies. The enhanced response of carbachol at the low temperatures or the relative potency of carbachol and pilocarpine in the tissue obtained from the diseased donors was not significantly different from that of controls. Based on EC50 values, the potency of arecoline on the iris was 1/3 that of carbachol. Significantly lower EC50 values of carbachol were found in irides which were in contact with open loop type anterior chamber lens implants compared with those in contact with the closed loop anterior chamber lens implants. Maximum responses of irides to carbachol were less when the tissue was in contact with open loop lens compared with those in contact with closed loop anterior chamber implants. Irides from many donors having unilateral or bilateral replacement of the artificial lenses responded with EC50 of carbachol which was approximately equal to that of the contralateral eye. The maximum difference between EC50 values of the left and right iris was less than 5 fold. Paired irides with asymmetric surgical procedures responded unequally to carbachol. The dissociation constant KB of atropine (1 nmol/1) at 17°C was equal to that observed at 37.5°C. The KB values of himbacine, methoctramine and pirenzepine were 120, 1500, 120 nmol/1, respectively. From one tissue to another, there was a spread in the dissociation constant value of pirenzepine indicating that human iris sphincter may contain heterogenous population of muscarinic receptors. Springer-Verlag, 1992 Human iris-sphincter nationallicence Iris receptor in disease nationallicence Lens replacements nationallicence Intra ocular lens nationallicence Pirenzepine nationallicence Methoctramine nationallicence Muscarinic receptor subtypes nationallicence Patil Popat Division of Pharmacology, College of Pharmacy and Department of Ophthalmology, College of Medicine, the Ohio State University, 43210, Columbus, OH, USA aut Manger Thomas Division of Pharmacology, College of Pharmacy and Department of Ophthalmology, College of Medicine, the Ohio State University, 43210, Columbus, OH, USA aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/6(1992-12-01), 620-628 0028-1298 346:6<620 1992 346 210 https://doi.org/10.1007/BF00168734 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00168734 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Patil Popat Division of Pharmacology, College of Pharmacy and Department of Ophthalmology, College of Medicine, the Ohio State University, 43210, Columbus, OH, USA aut NATIONALLICENCE 700 1- Manger Thomas Division of Pharmacology, College of Pharmacy and Department of Ophthalmology, College of Medicine, the Ohio State University, 43210, Columbus, OH, USA aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/6(1992-12-01), 620-628 0028-1298 346:6<620 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 469078081 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer