title: Distribution of atrial natriuretic peptide and its effects on contraction and intracellular calcium in ventricular myocytes from streptozotocin-induced diabetic rat.
abstract: The distribution of atrial natriuretic peptide (ANP) in blood plasma and cardiac muscle and its effects on ventricular myocyte contraction and intracellular free calcium concentration [Ca2+]i in the streptozotocin (STZ)-induced diabetic rat have been investigated. Blood plasma concentration and heart atrial and ventricular contents of ANP were significantly increased in STZ-treated rats compared to age-matched controls. STZ treatment increased the number of ventricular myocytes immunolabeled with antibodies against ANP. In control myocytes the percentage of cells that labeled positively and negatively were 17% versus 83%, respectively. However, in myocytes from STZ-treated rat the percentages were 52% versus 53%. Time to peak (TPK) shortening was significantly and characteristically prolonged in myocytes from STZ-treated rats (360+/-5 ms) compared to controls (305+/-5 ms). Amplitude of the Ca2+ transient was significantly increased in myocytes from STZ-treated rats compared to controls (0.39+/-0.02 versus 0.29+/-0.02 fura-2 RU in controls) and treatment with ANP reduced the amplitude of the Ca2+ transient to control levels. ANP may have a protective role in STZ-induced diabetic rat heart.
authors.affiliation: Department of Physiology, Faculty of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, UAE. chris.howarth@uaeu.ac.ae
authors.forename: F C
authors.initials: FC
authors.lastname: Howarth
authors.forename: A
authors.initials: A
authors.lastname: Adem
authors.forename: E A
authors.initials: EA
authors.lastname: Adeghate
authors.forename: N A
authors.initials: NA
authors.lastname: Al Ali
authors.forename: A M
authors.initials: AM
authors.lastname: Al Bastaki
authors.forename: F R
authors.initials: FR
authors.lastname: Sorour
authors.forename: R O
authors.initials: RO
authors.lastname: Hammoudi
authors.forename: N A
authors.initials: NA
authors.lastname: Ghaleb
authors.forename: N J
authors.initials: NJ
authors.lastname: Chandler
authors.forename: H
authors.initials: H
authors.lastname: Dobrzynski
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000494:pharmacology* / Q000502:physiology*; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000503:physiopathology*; D006352:Heart Ventricles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D032342:Muscle Cells / Q000187:drug effects / Q000502:physiology*; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000633:toxicity
chemical_list: D013311:Streptozocin; D009320:Atrial Natriuretic Factor